SoundExpertSoundExperthttp://soundexpert.org/articles/-/blogs/rss2024-03-28T23:35:25Z2024-03-28T23:35:25ZAudio-Transparency InitiativeSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-transparency-initiative2021-09-12T16:49:16Z2020-08-15T13:53:00Z<p> <img alt="A boy playing flute, bronze statue" src="http://soundexpert.org/documents/10179/1842467/se-atinitiative-cover.jpg" style="width: 1000px; height: 553px;" /></p> <p> <strong>The Audio-Transparency Initiative focuses on shifting a listener's attention from gadgets and technology to music and its authors. To this end, clear guidelines are proposed for designing and manufacturing audio equipment with extremely low sound degradation, inaudible to human hearing. A transparent audio path - an ideal channel for communication between music authors and listeners - should become a new norm and a standard commodity. The accompanying study of the audio quality in the market of portable players is aimed at (1) defining the required level of transparency for audio equipment and (2) showing how far current portable players are from this level. Exceptional audio quality at low prices can be achieved through the united effort of music lovers.</strong></p> <p style="text-align: right;"> Music is the universal language of mankind.<br /> Henry Longfellow<br /> <br /> Music is everybody's possession.<br /> It's only publishers who think that people own it.<br /> John Lennon</p> <p> <span style="font-size:18px;"><strong>I</strong></span>t is not currently possible to say with certainty how and why our species of Homosapiens started to sing (hunting, rituals/dances, lullabies, language-genesis, etc.). Our closest relatives in the animal world - chimpanzees - have no such musical behavior at all (and poorly developed larynxes), but, for example, among birds, it is common. At the same time, in all known human communities, musical culture in one form or another is inherently present, and some researchers believe that the Neanderthals were even more musical than us. Considering that the oldest known musical instrument is about 37000 years old (primative bone-flute with holes), we can confidently say that our musical culture has its roots in the very earliest stages of the emergence of humans as a species, and that music itself is one of the oldest forms of social interaction.</p> <p> With the emergence and extinction of new hearths of human civilization, our musical practices also developed. Despite local successes (ancient Egypt, India, Greece, etc.), musical culture up to the Renaissance was quite basic and most people could easily be both listeners and performers. The rise of Western civilization at the end of the Late Middle Ages gave a powerful impetus to the development of science, technology, and culture as a whole. The deepest and most important component of any culture - music - also experienced a rapid blossoming. There appeared advanced musical notation, professional composers and performers, new musical genres and instruments, a music economy, entrepreneurs, sound recording and distribution of the recordings to listeners. A deeper understanding of the structure of music appeared, its regularities, peculiarities and perception by humans. In the context of the current initiative, two aspects of this musical evolution are most interesting.</p> <p> <strong>Musical instruments</strong>. Since about the 15th century, the variety and complexity of musical instruments increased drastically. The separation of musicians from listeners began and reached its peak at the end of the 20th century. With the advent of electronic musical instruments, sampling techniques and personal computers, the process of separation began to slow and even reverse. It became possible to create music at home without requiring an education in music. The rapid development in recent years of AI technology has led to the emergence of so-called generative music [<a href="https://mubert.com/" target="_blank">Mubert</a>, <a href="https://openai.com/blog/jukebox/" target="_blank">Jukebox</a> ...]. Such "artificial" music in terms of its technical and, most importantly, artistic characteristics is already not so different from the human creation (we often hear it now without knowing the origin). The mass availability of AI technologies will inevitably lead to the explosive growth of people making music, further blurring the boundary between musicians and listeners. Each person will have the opportunity to compose and perform new music by training a neural network with some selected music material and the author's music experiments - playing instruments, and/or singing. The "quality" of such music may be questionable but the quantity will be huge and there will surely be some outstanding examples.</p> <p> <strong>Music economy</strong>. Somewhere around the turn of the 18th century, more elaborate music started to develop and move beyond the realms of churches and the mansions of noble people and began to flourish on its own. The first music intermediaries and managers appeared, helping musicians to organize performances, and to inform and encourage listeners to attend those performances. The commercialization of music had begun. This process also reached its peak at the end of the 20th century, when most of the music business found itself in the hands of the four record companies - EMI, Sony Music Entertainment, Universal Music Group, and Warner Music Group. In the music market, they set the rules for both musicians and listeners. Over two centuries, the humble helpers had turned into the owners of the world music business, controlling almost any interaction between musicians and listeners, and taking the bulk of all profits. To be fair, it should be noted that despite such an unhealthy commercial situation, the recording industry in the 20th century produced a huge number of real musical masterpieces that will be in demand for several generations of listeners. And again, the technological progress in the late 20th century changed the rules of the game. Internet, compact audio file formats (mp3, FLAC, etc.), and decentralized file-sharing protocol (Bittorrent) have formed an open technological environment for direct communication between musicians and listeners. During the last two decades we have been actively searching for new forms of such interaction: personal websites/blogs of musicians, services for promotion/sales of their music (MySpace, Soundcloud, TuneCore, FB Social Audio), free distribution of music by authors, payment by the formula of "pay what you want", direct financial support of musicians by listeners and participation in their releases. Despite the serious complications of this process, there is little doubt it will be successful because musicians and listeners need each other, they have all required network technologies for self-organization, and the differences between them, as mentioned above, are becoming increasingly blurred and conditional. Conversely, any closed proprietary mass delivery channels for music on any medium would seem to have no future. Meanwhile, new types of intermediary services will be in demand as listener navigation in the new boundless ocean of music becomes more and more complicated, and musicians require increasingly sophisticated technical support. It is worth adding that it will remain very challenging to create great works and hits.</p> <p> Thus, having made dizzying progress together with Western civilization, musicians and listeners are uniting again. The question of whether to listen to, or to write, music will soon be a question of mood and preference. However, another barrier between musicians and listeners remains.</p> <h3> Playback obsession</h3> <p> Following the advances in sound recording that began in the late 19th century, rapidly-increasing technical complexity resulted in musicians starting to require the assistance of sound engineers. The quality of the final product - the master record - became highly dependent on their knowledge, experience, and musical taste. Listeners also needed technically advanced devices for sound reproduction. While the technology and equipment are much more complex for recording than for playback and the skill of the sound engineer has a significant impact on the final quality of the recording, the quality of the listening experience has been mostly associated with playback devices. In Hi-Fi/Hi-End magazines, forums, websites, etc., the characteristics of recorded sound such as detail, resolution, imaging, timbre, layering, sound stage depth and width, fidelity, transparency, etc., are invariably discussed only in the context of the playback audio path. It is difficult to say why such an unnatural discourse has emerged. Perhaps it can be explained by the fact that the first playback devices were truly of poor quality, and their advancement was seen as the main potential for improving the listening experience. Perhaps economic factors also played a role - the nascent market for playback equipment looked promising, and so the issue of sound quality was debated mostly within the marketing of these new consumer devices. But whatever the reason, this crafty approach remains dominant to this day and, it should be noted, is fully in the interests of manufacturers of consumer audio equipment.</p> <h3> Flawed audiometric</h3> <p> This confusing tradition is favored by the fact that a listener has the last word in determining the sound quality of an audio device and there is no reliable method of measuring it with an instrument. The traditional set of objective audio parameters - THD, IMD, SNR, frequency response, etc. - does not correlate well enough with subjectively-perceived sound quality. This was well known to audio engineers from the very beginning. With the advent of digital-audio technology, this weakness of traditional audiometric (TAM) became even more evident. Today, only an experienced audio specialist can benefit from the results of traditional measurements; the average user is unable to interpret them correctly. While a manufacturer of audio equipment necessarily has such a specialist in the staff and no doubt clearly understands the actual quality of its products, the listener has to rely only on his/her feelings and impressions from listening. And the listening experience is strongly influenced by many extraneous factors - the appearance of the device, its brand and price, reviews and friends' advice, etc. In short, the manufacturer knows everything about the product; the consumer knows little more than nothing. Such an information asymmetry in the market creates the opportunity for a manufacturer to pass off lower-quality goods as high-quality [<a href="https://en.wikipedia.org/wiki/Information_asymmetry" target="_blank">Information Asymmetry</a>, G. Akerlof]. This is exactly what has happened in the consumer audio market and, to a lesser extent, in the professional market. Taking advantage of this information asymmetry, manufacturers have gradually become more focused on marketing rather than research and development. As a result, today's audio equipment prices are mostly backed by quasi-scientific marketing stories. Thousand-dollar audio cables and fabulously expensive high-end products are the most egregious manifestations of this phenomenon.</p> <p> This exaggerated importance of modern playback equipment is the last barrier between musicians and listeners. This barrier can be safely removed with the help of a new approach to designing an audio path and an assessment of its quality. The integral part of this approach is the new audiometric - df-metric, which was developed to overcome the shortcomings of TAM [<a href="http://soundexpert.org/documents/10179/11017/se-audio-metric.pdf" target="_blank">Audio metric that makes a difference</a>].</p> <h3> The basic idea of df-metric</h3> <p> In its simplest form, the basic idea of the new audiometric can be explained as follows. Since sound is entirely determined by the shape of the sound wave, the task of preserving the sound quality is the task of preserving the waveform of a signal along the audio path. The level of degradation (distortion) of the waveform is measured with a special parameter - Difference Level, dB [<a href="http://soundexpert.org/documents/10179/11017/DiffLevel_AES118.pdf" target="_blank">Difference Level. An objective audio parameter</a>]. The main advantage of this parameter is the ability to measure the degradation of any signals, including real music. When using the latter, this parameter correlates well with the results of listening tests.</p> <h3> Why traditional audiometrics work poorly</h3> <p> Experiments with signals of different waveforms that were used for testing real audio devices helped to identify the main cause of the low efficiency of TAM. The figure below shows the results of testing eleven players with signals of various waveforms: music, noise, rectangular, triangular, and sinusoidal signals [the source: <a href="http://soundexpert.org/articles/-/blogs/audio-quality-of-high-end-portable-players" target="_blank">Audio Quality of High-End Portable Players</a>]. The devices in the picture are sorted by Df levels of the real music signal.</p> <p> </p> <table align="center" style="width:100%;"> <tbody> <tr> <td> <img alt="Test of portable players with signals of different waveforms" src="http://soundexpert.org/documents/10179/1842467/mt-signals.png/9a0eabfb-6c27-4cb3-ac5a-efc7a788311e?t=1597500261000" style="width: 501px; height: 500px;" /></td> <td> <p style="margin-left: 80px;"> <strong>Test of portable players with signals of different waveforms</strong>: real music [<a href="http://soundexpert.org/test-signals#variety" target="_blank">Test set of music material "Variety"</a>], noise signal simulating real music (BS EN 50332-1), rectangular, triangular and sinusoidal signals. The correlation of Df levels of each signal with Df levels of the music signal is indicated.</p> </td> </tr> </tbody> </table> <p> </p> <p> We can see that the noise signal correlates best with the music signal (r=0.99), and the correlation with the sinusoidal signal is the lowest (r=0.69). It should be noted that when using a sinusoidal signal the value of the Df parameter is equal to THD+Noise of TAM (they differ from each other by 3 dB). The signals of different waveforms do not degrade accordingly or consistently. Each time we measure the quality of a group of devices with a new signal, we get a new ranking of their quality. Thus, the initial assumption that smaller distortion/degradation of one signal (typically sinusoidal) results in smaller distortion/degradation of other signals turns out to be false. A device that reproduces a sinusoidal signal more accurately than other devices may in fact be less accurate in reproducing a signal of a different waveform.</p> <p> If the results of measurement depend on the type of test signal used, there is a question - which test signal should be preferred while measuring? The answer is obvious - real music/speech signals (or its noise equivalent). Audio equipment should be designed to work exactly with such signals.</p> <p> Recent attempts to expand the list of test signals used in TAM can increase its efficiency only to a small extent because of the low correlation between measurements with different test signals. Today, TAM is reminiscent of Ptolemy's model with the Earth at the center, where an ever-increasing number of new epicycles had to be introduced to predict the positions of the planets more precisely. Finally, it was replaced by a heliocentric model, which proved to be both simpler and more accurate. An audiometric can provide similar benefits by eliminating the use of narrow technical signals to predict the sound quality of audio devices. There should be real music/speech signals in the center.</p> <h3> Features and benefits of df-metric</h3> <p> In the df-metric, technical signals are used only for testing specific aspects of device performance and are interesting mainly to developers and engineers. The actual sound quality of a device is measured with statistical methods using a large array of varied sound material (music and speech).</p> <p> Benefits of the new audiometric:</p> <ul> <li> a fairly simple and inexpensive way to measure Difference Level</li> <li> df measurements give a comprehensive picture of device audio performance</li> <li> higher correlation of measurements with subjective sound quality due to use of real-world sound signals</li> <li> easier interpretation of measurement results, understandable to the layperson</li> <li> Df parameter can be used for both analog and digital signals (regardless of sample rates for the latter)</li> <li> df-metric helps to determine the lower threshold of sound signal degradation, at which this degradation becomes imperceptible for any listener (or a majority of listeners). In other words, it helps to determine the required transparency level of an audio path. Such transparency level can be determined both theoretically and based on measurements of real audio devices in the market. If necessary, it is possible to define several additional classes of semi-transparency.</li> </ul> <p> One disadvantage of the Df parameter is its indifference to the nature/type of signal degradation. As we know, not all distortions are equally perceptible. However, all current audio engineering experience shows that weighing different types of degradation of real sound signals according to psychoacoustic regularities is hopelessly difficult. Their noticeability significantly depends both on the nature of the musical signal (genre, saturation, tempo, ...) and on the peculiarities of perception of a particular listener - his/her listening experience, musical preferences, features of his/her hearing (age), and even on the cultural musical environment in which the listener grew up (perception of consonances and dissonances). With such a set of complicating factors the establishment of any universally agreed objective audiometric that takes them all into account is simply impossible. Fortunately, there is no such need anymore.</p> <h3> The engineering approach to sound quality; a new paradigm</h3> <p> The current level of technology allows design and production of audio equipment with low level of distortion/degradation of a music signal. Available data measurements of real audio devices show that the audio transparency level for different types of devices is in the range from -70 dB to -90 dB and some devices on the market already provide such accuracy. In other words, today it is easier to provide the required transparency of an audio path by engineering methods than to sort out which distortions are acceptable due to their low audibility for hearing, and which should be excluded. The paradigm of <i>inevitable distortions</i> can be safely and permanently dispensed with; this is just the breeding ground for marketing abuses in the audio industry. This is especially true for manufacturers of High-End equipment, who are essentially the <i>sellers of distortions</i>, deluding their customers into believing their distortions are "the most musical, fully revealing the richness of recorded sound". The new paradigm of <i>transparent audio</i> (lossless digital/analog audio path) is more honest and allows us to shift the focus of listeners' attention from manufacturers of audio equipment to the creators of recordings [<a href="http://soundexpert.org/articles/-/blogs/hofi-%E2%80%93-the-honest-audio" target="_blank">The Honest Audio</a>]. Those in the studio should determine the warmth, depth, detail - the characteristics of sound tirelessly discussed in magazines and on sites devoted to playback equipment, supported by advertising budgets of audio manufacturers. The discussion of all those sound nuances with the manufacturer makes no more sense than a discussion of the content of letters you receive from the postman. Any sound playback equipment is just a communication channel for an audio signal and the sound quality of this channel is fully determined by only one parameter - the accuracy of music signal reproduction - the transparency of the channel. If, for some reason, achieving the required level of transparency isn't possible, it might make sense to allow certain distortions using our knowledge of psychoacoustics, but such exceptional cases are increasingly scarce nowadays.</p> <p> Besides strengthening the role of authors, musicians, and engineers, the proposed paradigm has several additional features and advantages:</p> <ul> <li> Easy customer control of the quality of audio products thanks to a reliable and affordable measurement method.</li> <li> Recovery of consumer audio market by displacing unnecessarily expensive devices of dubious quality and replacing them with equipment of minimal price/quality ratio. Outstanding sound quality at minimum price is the next technological step in audio.</li> <li> Commoditization of many hardware audio solutions and improvement of their quality thanks to clear guidelines for their design and manufacturing. Everything that produces sounds, can sound perfect. It's not only a question of aesthetics, it is a question of our hearing health too.</li> <li> For audiophiles who practice attentive listening, there will be an easy way to achieve the best sound. As the experience of listening to a recorded sound cannot be any better than that achieved in the studio, preparing a listening environment according to studio standards becomes a simple and logical guide. The appropriate recommendations in the sphere of professional audio are well understood. The very division of audio equipment by sound quality (not by functionality) into professional and consumer looks increasingly far-fetched. Ideally, quality-wise, they should be identical. Not the least because the line separating creators of recordings from their listeners is becoming less distinct.</li> <li> For those who believe that a recording can sound better than that in the studio, a new market of software plug-ins for <em>creative listening</em> is opening up. A transparent audio path can be easily supplemented with sound processing tools: EQs, HRTFs, correctors of room acoustics and frequency response of speakers/headphones, tube/vinyl sound emulators, enhancers of depth, width, warmth, detail ..., vocal removers and other audio-photoshop filters. The list is limited only by the imagination of developers.</li> </ul> <p> These changes will also affect traditional listening rituals. Instead of heating the tube amps, cleaning the vinyl, and placing the cartridge onto the groove, we will have:</p> <ul> <li> reading/viewing additional information about the author/artist and his motives for creating the track;</li> <li> searching for technical details of the record creation - equipment, technology, drawbacks/mistakes;</li> <li> listening to a pair of warm-up tracks of the same style/genre from another author/performer;</li> <li> after listening, perhaps leaving a comment on the author's page or even providing some small form of financial support.</li> </ul> <p> Connection ritual is an important procedure for any attentive listener and its variants can be numerous, not only maintenance of the sound system, which soon maybe invisible to the listener (in-wall speakers, control from phone/tablet, etc.).</p> <h3> A step towards better audio</h3> <p> Many manufacturers today can produce sound equipment of the required quality/transparency level. The new audiometric provides clear recommendations for developers as to what technical parameter should be achieved for this purpose. However, for manufacturers to start doing this, they must be sure that (a) the recommended value of the Df parameter provides the required transparency level and (b) there is sufficient market demand for such devices/solutions. Listeners need to send a clear message to manufacturers, with an informed purchasing decision reflecting their preferences.</p> <p> Both tasks can be solved by testing audio equipment on the market according to the new audiometric. First, such a study will make sure that the metric works and that the best examples of audio equipment have higher transparency levels. Secondly, it will help to determine more precisely the required level of transparency based on the current market overview. For the study results to be convincing and statistically meaningful, the number of devices examined should be sufficiently large, in excess of 100 models. For many reasons this study is easier to perform for specific segments of the market such as Digital Portable Audio:</p> <ul> <li> This is a popular way of listening to music in good quality both at home and on the go; almost half of all listeners are using top/specialized smartphones for this purpose. Therefore, the results of this segment of the study should be of interest to many people.</li> <li> This market segment is rather small, so almost all such devices can be tested, clearly showing who is who in portable audio.</li> <li> Portable players usually have a relatively low level of transparency (though there are exceptions), which allows use of inexpensive measurement equipment (for example, the $200 TI PCM4222 Evaluation Module). Therefore, many audio enthusiasts will be able to participate in testing over a relatively short period of time.</li> <li> The measurement method was developed/perfected while testing portable devices [<a href="http://soundexpert.org/articles/-/blogs/audio-quality-of-high-end-portable-players" target="_blank">hi-end DAPs</a>, <a href="http://soundexpert.org/portable-players-beta2" target="_blank">beta2</a>, <a href="http://soundexpert.org/portable-players-beta" target="_blank">beta1</a>], so there is already a good understanding of both the possible difficulties of the measurement process and the expected results.</li> </ul> <p> Successful experience gained in this market segment can be extended to other burgeoning areas of audio, such as wireless headphones.</p> <p> </p> <p> <img alt="Pump.a.DAP Campaign" src="http://soundexpert.org/documents/10179/1842467/pump-a-dap.jpg/ad70876e-17ff-4775-9b58-4397ccd51b16?t=1597501875000" style="width: 1000px; height: 220px;" /></p> <p> Digital portable audio mass testing campaign "Pump.a.DAP" will be carried out:</p> <ul> <li> with open discussion of its progress and results:</li> <li style="margin-left: 40px;"> <span style="indent:1;">The page with the results - <a href="http://soundexpert.org/vault/dpa.html" target="_blank">http://soundexpert.org/vault/dpa.html</a></span></li> <li style="margin-left: 40px;"> <span style="indent:1;">Facebook page - <a href="https://www.facebook.com/Pump.a.DAP/" target="_blank">https://www.facebook.com/Pump.a.DAP/</a></span></li> <li style="margin-left: 40px;"> <span style="indent:1;">SE Twitter - <a href="https://twitter.com/SoundExpertOrg/" target="_blank">https://twitter.com/SoundExpertOrg/</a></span></li> <li> according to clearly defined/described measurement procedure and using open-source software [<a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion#part3" target="_blank">Diffrogram</a>];</li> <li> using open accounting, as the campaign will require some funding.</li> </ul> <h3> Who is invited to participate in the campaign</h3> <p> <b>Audio enthusiasts</b> who already have TI PCM4222 Evaluation Module (or ready to purchase it) and who can perform simple measurement procedures. As usual, the authors of the measurements will be mentioned on df-slides with results.</p> <p> <b>Stores of portable audio</b>, planning to offer their customers high-quality devices with the best price/quality ratio; the campaign will need access to a large number of models that would be very expensive to purchase otherwise.</p> <p> <b>Audio forums and discussion platforms</b>, ready to provide a special place for discussion of testing progress and working issues.</p> <p> <b>Scientific and research organizations</b>; this study has a good potential for becoming the basis for the development of new standards in audio.</p> <p> <b>All music lovers and DAP users</b> who are tired of marketing noise/hype around portable audio, who would like to see a real picture of quality in this segment of the market, and who are willing to support this initiative/campaign by sharing its news or with small donations. You most likely will be the only source of funding for this campaign, which is carried out for the benefit of ordinary listeners, possibly to the detriment of certain audio manufacturers, who are perfectly satisfied with the current market status quo. All donations will be mentioned on the page with the results of this mass testing [<a href="http://soundexpert.org/vault/dpa.html#screen-of-fame" target="_blank">Screen of Fame</a>]. If you decide to donate, don't forget to specify the model of the player whose measurements you would like to see. These models will be given priority for testing.</p> <h3> A step towards a better future</h3> <p> The 21st century has already become a turning point in the musical life of the planet. New ways of delivering music to listeners, decentralized music sharing, experiments with new music economy, remastering of old recordings, the democratization of music creation, the increasing use of AI methods for creation, processing, recognition of music and speech, VR and binaural/immersive audio ... At the same time, manufacturers of consumer audio equipment for the most part continue to live in the 20th century and still prefer to earn their money through extensive and sometimes deceptive marketing.</p> <p> The advent of the Internet created a profound transformation of human society. The main driving force behind this change is broad social self-organization. Music culture was one of the first to engage in this process - P2P Music was ahead of P2P Money. It turned out that many complex technical and economic challenges associated with our music culture can be solved ourselves, using the potential of a global network that can easily connect both listeners to listeners and listeners to musicians. Progress in many other areas that follow will depend on the developments in the music industry.</p> <p> <strong><span style="font-size:16px;">C</span></strong>ould we find and consolidate new practices of direct interaction between musicians and listeners, including new economic models? Or we will rely on third-party services with their internal corporate rules?</p> <p> <span style="font-size:16px;"><strong>W</strong></span>ill we be attentive to, and curious about, new authors and their music? Or we will continue to focus on gadgets and technical aspects of sound reproduction, just consuming music content from providers (mostly in the background)?</p> <p> <span style="font-size:16px;"><strong>W</strong></span>ill we, listeners and music lovers, be able to influence the audio market according to our interests and priorities? Or we will rapturously look at the manufacturers who still manage/manipulate this market by knowingly shaping the interests of audio technology users?</p> <p> The answers to these questions will partly determine the future that we choose to create:</p> <p> </p> <p> <strong>a future with intensifying competition and invention of ever more civilized ways of deceiving each other, with infinitely stimulated consumption and decisions made within closed interest groups;</strong></p> <p> or,</p> <p> <strong>a future that is based largely on cooperation and attention to each other, transparent decision-making, and respect for nature and resources.</strong></p> <p> </p> <p> The Audio-Transparency Initiative and corresponding testing campaign, designed to shift listeners' attention from technology to music and its authors, is the first step towards a better future. If you would like to participate, feel free to share this <strong>#AudioTransparency</strong> initiative with your friends and colleagues:</p> <ul> <li> the permanent link to the initiative - <a href="http://soundexpert.org/audiotransparency">http://soundexpert.org/audiotransparency</a></li> </ul> <p> You can also:</p> <ul> <li> leave your comment below,</li> <li> contact us directly - <a href="http://soundexpert.org/contact-us" target="_blank">http://soundexpert.org/contact-us</a></li> <li> donate to the testing campaign - <a href="http://soundexpert.org/vault/dpa.html#screen-of-fame" target="_blank">http://soundexpert.org/vault/dpa.html#screen-of-fame</a></li> </ul> <p> <strong><span style="font-size:16px;">T</span></strong>hanks for your support and encouragement! Exceptional audio quality for everyone is not a utopia, but a real goal that can be achieved through the efforts of consumers alone.</p> <p> </p> <p> </p> <p> </p> <hr /> <p> Thanks, HypetheSonics for heavy editing the text and especially for the “edge rounding”. Definitely it's much more clear now.</p> <p> </p> <h3> Appendix</h3> <h4> A few words in-person</h4> <video controls="" height="970" style="border: 1px solid #999999; padding: 14px;" width="970"> <source src="http://soundexpert.org/media/ati-video.mp4" type="video/mp4"> Your browser does not support the video tag. </source></video>Serge Smirnoff2020-08-15T13:53:00ZDf-measurements of DA/AD loops from Gearslutz forumSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/gearslutz2020-06-15T19:54:01Z2020-05-18T13:08:00Z<p> <strong><span style="font-size:16px;">M</span></strong>easurements of difference signal can be made with a few software tools nowadays. Probably the first publicly available such tool was the <a href="http://libinst.com/Audio%20DiffMaker.htm" target="_blank">Audio DiffMaker</a> from Liberty Instruments. The latest one is the <a href="https://deltaw.org/" target="_blank">DeltaWave Audio Null Comparator</a> from Paul K.</p> <p> Since 2011 the enthusiasts from Gearslutz forum are performing difference measurements of various AD/DA converters and audio interfaces by means of the Audio DiffMaker using 2 min clip of classical music as a test signal. To the moment more than 200 measurements are completed and can be found in <a href="https://www.gearslutz.com/board/showpost.php?p=14630377&postcount=1922" target="_blank">this post</a>. As most recordings that were used for computing and measuring difference signal are still available for downloading, I performed standard SE df-measurements for them and computed similarity of their artifact signatures. Resulting 3D map of the tested devices is below (you can zoom and rotate):</p> <script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three.r81.min.js"></script><script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three_d.js"></script> <div id="sim-space" style="margin: 0 50px;"> </div> <script type="text/javascript"> function init_plot() { var params = {}; params.width = 900; params.height = 900; params.font = "Verdana, Arial, sans-serif"; params.div_id = "sim-space"; params.background_color = "#FFFFFF"; params.show_axis_titles = false; //params.axis_color = "#999999"; params.same_scale = [true, true, true]; //params.axis_font_color = "#999999"; //params.axis_font_size = 16; //params.x_scale_bounds = [0, 0.5]; //params.y_scale_bounds = [0, 0.5]; //params.z_scale_bounds = [0, 0.5]; params.show_box = false; params.show_snaps = false; params.show_toggles = false; params.show_ticks = true; params.grid_color = "#dddddd"; 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{"x":3.0814,"y":3.6885,"z":1.4755,"color":"#3AA654","label":"DA24MkII>PCM4222EVM-m(170)"}, {"x":3.1083,"y":2.9460,"z":0.4212,"color":"#2EA66B","label":"Madison>PCM4222EVM-m(171)"}, {"x":0.6816,"y":1.1648,"z":1.1322,"color":"#5AA535","label":"Juli@XTe>StudioADC-m(172)"}, {"x":0.2731,"y":1.3636,"z":1.3258,"color":"#7BA12B","label":"RossMartin>Halo-m(173)"}, {"x":0.2882,"y":1.3496,"z":1.3710,"color":"#7BA12B","label":"Hilo-m>MOTU828(174)"}, {"x":0.3034,"y":1.3580,"z":1.3635,"color":"#7BA12B","label":"MOTU828U>MOTU828F-m(175)"}, {"x":0.3014,"y":1.3547,"z":1.3007,"color":"#7CA12B","label":"MADA2>PCM4222EVM-m(176)"}, {"x":0.3524,"y":1.3092,"z":1.3569,"color":"#7EA02B","label":"LIO8>B2Bomber(177)"}, {"x":0.4358,"y":1.2263,"z":1.3046,"color":"#81A02B","label":"GXD8>B2Bomber-m(178)"}, {"x":0.2901,"y":1.3688,"z":1.2892,"color":"#81A02B","label":"DA24Mk2>iD22-m(179)"}, {"x":3.3641,"y":1.2422,"z":1.9632,"color":"#81A02B","label":"Aurora16>Blue245-m(180)"}, {"x":2.3695,"y":1.3415,"z":1.5249,"color":"#899D2C","label":"Aurora>PCM4222EVM-m(181)"}, {"x":0.3111,"y":1.2961,"z":1.3628,"color":"#8B9D2C","label":"GXD8>ConvertAD+m(182)"}, {"x":2.3435,"y":1.3121,"z":1.5606,"color":"#899D2C","label":"Hilo>MOTU828U-m(183)"}, {"x":2.6285,"y":0.8220,"z":1.3654,"color":"#8B9D2C","label":"Scarlett18i20>ZenTour(184)"}, {"x":3.2410,"y":0.9078,"z":1.7669,"color":"#889E2C","label":"MOTU828MkII>Hilo-m(185)"}, {"x":3.3570,"y":0.9277,"z":1.6226,"color":"#899D2C","label":"XMC1>Hilo-m(186)"}, {"x":0.2917,"y":1.3858,"z":1.3484,"color":"#8D9C2C","label":"DA924>AD12296MkII(187)"}, {"x":0.2734,"y":1.3692,"z":1.3558,"color":"#8E9B2C","label":"AES8DAC>PCM4222(188)"}, {"x":0.2773,"y":1.3720,"z":1.3708,"color":"#8E9B2C","label":"AES8DAC>PCM4222ADC-m(189)"}, {"x":0.2821,"y":1.3464,"z":1.2978,"color":"#8D9C2C","label":"MDAC4>MADC2-m(190)"}, {"x":2.3250,"y":1.1613,"z":1.5298,"color":"#8E9C2C","label":"MADA2>Aurora16-m(191)"}, {"x":2.8153,"y":1.0390,"z":1.6956,"color":"#8A9D2C","label":"UH7000>Hilo-m(192)"}, {"x":1.0833,"y":1.3477,"z":1.3858,"color":"#99972D","label":"AudientID14>Hilo(193)"}, {"x":1.1624,"y":1.3291,"z":1.3884,"color":"#98982D","label":"XDA1>Lyra1(194)"}, {"x":1.5268,"y":1.3785,"z":1.3493,"color":"#929A2C","label":"Aurora16>MADA2-m(195)"}, {"x":0.6874,"y":1.1452,"z":2.9533,"color":"#94992D","label":"DA3000>MytekS-m(196)"}, {"x":0.2530,"y":1.4734,"z":1.4283,"color":"#AA8C2F","label":"DigiR>MytekS-m(197)"}, {"x":3.1272,"y":4.4959,"z":1.8751,"color":"#56A538","label":"Aurora>PCM4222EVM(198)"}, {"x":0.2764,"y":1.3629,"z":1.3571,"color":"#7EA02B","label":"DAC2HGC>MytekS(199)"}, {"x":0.3314,"y":1.3150,"z":1.2397,"color":"#81A02B","label":"DAC1>ZenTour(200)"}, {"x":0.3114,"y":1.3454,"z":1.3521,"color":"#829F2B","label":"MDAC4>ML9600(201)"}, {"x":2.5616,"y":1.0953,"z":1.6251,"color":"#8C9C2C","label":"DAC2HGC>DigiR(202)"}, {"x":0.2642,"y":1.3841,"z":1.3238,"color":"#94992D","label":"AkaiZ8>EMU1212M(203)"}, {"x":0.3201,"y":1.1451,"z":0.9692,"color":"#7BA12B","label":"LGV30>MOTU828MkII(204)"}, {"x":0.0848,"y":1.1876,"z":0.1231,"color":"#7DA02B","label":"MOTUUltra>MytekS(205)"}, {"x":0.2590,"y":1.3613,"z":1.3713,"color":"#9E942E","label":"DAC2HGC>PMD661(207)"}, {"x":0.6796,"y":1.5141,"z":3.0098,"color":"#94992D","label":"DA3000>MytekS(208)"}, {"x":0.3518,"y":1.2237,"z":1.5911,"color":"#9C952E","label":"DAC2HGC>DA3000(209)"}, {"x":0.2170,"y":1.4196,"z":1.4068,"color":"#A2922E","label":"DAC2HGC>MOTUUltra(210)"}]; three_d.make_scatter(params); } init_plot(); </script> <p style="margin-left: 40px;"> <strong>The tested devices in similarity space</strong>. The closer devices to each other, the more similar their artifact signatures. Colors of devices correspond to their df-measurements. The distance (mean-corrected MAE) of 2 dB is critical for relation of objective measurements to subjective scores. For devices that have close artifact signatures (distance < 2 dB) their perceived sound quality correlates well to df-measurements performed with real-life music material. The numbered list of tested devices is in the end of this article.</p> <p> </p> <p> <strong>Some conclusions</strong>:</p> <ul> <li> Most tested devices have df-levels around -40 dB and are grouped in two clusters according to similarity of their artifact signatures. Usually devices within a cluster use similar engineering/circuitry solutions.</li> </ul> <ul> <li> There is a small group of devices with higher precision around -69 dB: Texas Instrument PCM4222 Evaluation Module, Focusrite Blue 245, Forssell MDAC-4, MSB Platinum IV Plus DAC, MSB Platinum Studio ADC, SPL Madison, ReQuest Audio The Beast DAC, Swissonic DA24 MkII</li> </ul> <p> </p> <h3> Diffrograms of the tested devices</h3> <p> Df-measurements are computed with 400ms window, so 2 min test clip results in 302 df values. They are color-coded and presented in the form of diffrogram that shows how the test clip is distorted with time by each device(s). Overall df value of a device is represented by median (dB, highlighted in Bold) of these 302 values. Diffrograms can be clicked to enlarge.</p> <p> The devices are numbered in the same order as they are listed in the <a href="https://www.gearslutz.com/board/showpost.php?p=14630377&postcount=1922" target="_blank">original Gearslutz forum post</a>, where you can find some details of the measurements and settings.</p> <p> While both DiffMaker and SE Matlab code measure the same physical entity - RMS amplitude of difference signal - they use different methods and scales, so resulting measurements have the constant shift of around 13 dB between them (original measurements by DiffMaker are in italics).</p> <p> </p> <h4 style="text-align: center;"> AD-DA converters performing from their internal clock</h4> <p> <strong>Lynx Hilo [Hilo]</strong><br /> (01) Hilo.wav(44)__Original2.flac(44)__mono_400-50.2321<strong>-45.6705</strong>-14.5383.png <a href="http://soundexpert.org/documents/10179/1964064/(01) Hilo.wav(44)__Original2.flac(44)__mono_400-50.2321-45.6705-14.5383.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(01) Hilo.wav(44)__Original2.flac(44)__mono_400-50.2321-45.6705-14.5383.png" width="60" /></a><br /> <em>CoolColJ - 6 last second part disregarded: -0,1 dB (L), -0,1 dB (R) Corr Depth: 41,8 dB (L), 43,7 dB (R), Difference: -59.1 dBFS (L), -59.2 dBFS (R)</em><br /> (02) Hilo Analog ref lev 0.wav(44)__Original2.flac(44)__mono_400-50.3200<strong>-45.7021</strong>-35.7222.png <a href="http://soundexpert.org/documents/10179/1964064/(02) Hilo Analog ref lev 0.wav(44)__Original2.flac(44)__mono_400-50.3200-45.7021-35.7222.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(02) Hilo Analog ref lev 0.wav(44)__Original2.flac(44)__mono_400-50.3200-45.7021-35.7222.png" width="60" /></a><br /> <em>sm5, line in and line out trims set at +0: -0.1 dB (L), -0.1 dB (R)..Corr Depth: 41,8 dB (L), 43,6 dB (R) Difference: -58.9 dBFS (L), -59.0 dBFS (R)</em><br /> (03) Hilo Analog ref lev 24.wav(44)__Original2.flac(44)__mono_400-50.3191<strong>-45.7019</strong>-35.7264.png <a href="http://soundexpert.org/documents/10179/1964064/(03) Hilo Analog ref lev 24.wav(44)__Original2.flac(44)__mono_400-50.3191-45.7019-35.7264.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(03) Hilo Analog ref lev 24.wav(44)__Original2.flac(44)__mono_400-50.3191-45.7019-35.7264.png" width="60" /></a><br /> <em>sm5, level line in and line out trims set at +24: 0.0 dB (L), 0.0 dB (R)..Corr Depth: 41,8 dB (L), 43,6 RMS Difference: -59.1 dBFS (L), -59.1 dBFS (R)</em><br /> (04) original2 loop through hilo play muted.wav(44)__Original2.flac(44)__mono_400-50.1501<strong>-45.6925</strong>-35.2391.png <a href="http://soundexpert.org/documents/10179/1964064/(04) original2 loop through hilo play muted.wav(44)__Original2.flac(44)__mono_400-50.1501-45.6925-35.2391.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(04) original2 loop through hilo play muted.wav(44)__Original2.flac(44)__mono_400-50.1501-45.6925-35.2391.png" width="60" /></a><br /> <em>capn357: 0.0 dB (L), 0.1 dB (R)..Corr Depth: 41,8 dB (L), 43,6 dB (R) Difference: -59.1 dBFS (L), -59.1 dBFS (R)</em><br /> <br /> <strong>Merging Technologies HAPI [HAPI]</strong><br /> (05) Merging ADA8 to ADA8.wav(44)__Original2.flac(44)__mono_400-55.6662<strong>-45.4191</strong>-33.2643.png <a href="http://soundexpert.org/documents/10179/1964064/(05) Merging ADA8 to ADA8.wav(44)__Original2.flac(44)__mono_400-55.6662-45.4191-33.2643.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(05) Merging ADA8 to ADA8.wav(44)__Original2.flac(44)__mono_400-55.6662-45.4191-33.2643.png" width="60" /></a><br /> <em>ADA8 ---> ADA8 (ljudatervinning): 0.391dB (L), 0.376dB (R) Corr Depth: 38,5 dB (L), 40,1 dB (R) Difference: -58,9 dBFS (L), -60,3 dBFS (R)</em><br /> (06) HAPI loopback ok.wav(44)__Original2.flac(44)__mono_400-43.0067<strong>-39.3632</strong>-30.9891.png <a href="http://soundexpert.org/documents/10179/1964064/(06) HAPI loopback ok.wav(44)__Original2.flac(44)__mono_400-43.0067-39.3632-30.9891.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(06) HAPI loopback ok.wav(44)__Original2.flac(44)__mono_400-43.0067-39.3632-30.9891.png" width="60" /></a><br /> <em>DA8P --> AD8DP (Touf on Pragmatic Audio): 0.08 dB (L), 0.07 dB (R) Corr Depth: 35,9 dB (L), 37,2 dB (R) Difference: -53.0 dBFS (L), -52.8 dBFS (R)</em><br /> (07) Merging ADA8 to AD8D.wav(44)__Original2.flac(44)__mono_400-43.2151<strong>-39.5650</strong>-31.3447.png <a href="http://soundexpert.org/documents/10179/1964064/(07) Merging ADA8 to AD8D.wav(44)__Original2.flac(44)__mono_400-43.2151-39.5650-31.3447.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(07) Merging ADA8 to AD8D.wav(44)__Original2.flac(44)__mono_400-43.2151-39.5650-31.3447.png" width="60" /></a><br /> <em>ADA8 ---> AD8D (ljudatervinning): 0,2 dB (L), 0,2 dB (R)..Corr Depth: 36,2 dB (L), 37,6 dB (R) Difference: -53.1 dBFS (L), -53.0 dBFS (R)</em><br /> <br /> <strong>Lynx Aurora(n) [AuroraN]</strong><br /> (08) AuroraN24_int.wav(44)__Original2.flac(44)__mono_400-50.2555<strong>-45.4771</strong>-35.3466.png <a href="http://soundexpert.org/documents/10179/1964064/(08) AuroraN24_int.wav(44)__Original2.flac(44)__mono_400-50.2555-45.4771-35.3466.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(08) AuroraN24_int.wav(44)__Original2.flac(44)__mono_400-50.2555-45.4771-35.3466.png" width="60" /></a><br /> <em>Mikathechou: 1.1 dB (L), 1.1 dB (R)..Corr Depth: 41,4 dB (L), 43,2 dB (R) Difference: -58.9 dBFS (L), -59.0 dBFS (R</em>)<br /> <br /> <strong>Antelope Pure2</strong><strong> [Pure2]</strong><br /> (09) Pure2 INT_05.wav(44)__Original2.flac(44)__mono_400-53.4379<strong>-43.2115</strong>-31.0659.png <a href="http://soundexpert.org/documents/10179/1964064/(09) Pure2 INT_05.wav(44)__Original2.flac(44)__mono_400-53.4379-43.2115-31.0659.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(09) Pure2 INT_05.wav(44)__Original2.flac(44)__mono_400-53.4379-43.2115-31.0659.png" width="60" /></a><br /> <em>Touf on Pragmatic Audio: -0.0 dB (L), -0,2 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.8 dBFS (L), -58.2 dBFS (R)</em><br /> <br /> <strong>Apogee Symphony I/0 Mk II [SymphonyMkII]</strong><br /> (10) Symphony mkii -.4.wav(44)__Original2.flac(44)__mono_400-53.5485<strong>-43.2271</strong>-31.0601.png <a href="http://soundexpert.org/documents/10179/1964064/(10) Symphony mkii -.4.wav(44)__Original2.flac(44)__mono_400-53.5485-43.2271-31.0601.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(10) Symphony mkii -.4.wav(44)__Original2.flac(44)__mono_400-53.5485-43.2271-31.0601.png" width="60" /></a><br /> <em>Diegel: -0.4 dB (L), -0.4 (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.8 dBFS (L), -58.2 dBFS (R) </em><br /> <br /> <strong>Metric Halo LIO-8 [LIO8]</strong><br /> (11) lio_loopback2.wav(44)__Original2.flac(44)__mono_400-53.2952<strong>-43.1898</strong>-31.0788.png <a href="http://soundexpert.org/documents/10179/1964064/(11) lio_loopback2.wav(44)__Original2.flac(44)__mono_400-53.2952-43.1898-31.0788.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(11) lio_loopback2.wav(44)__Original2.flac(44)__mono_400-53.2952-43.1898-31.0788.png" width="60" /></a><br /> <em>BrianVengeance: 3.0 dB (L), 3.0 dB (R)..Corr Depth: 36,4 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> <br /> <strong>Metric Halo ULN-8 3d [ULN8] </strong><br /> (12) ULN8 3D into itself.wav(44)__Original2.flac(44)__mono_400-53.3282<strong>-43.1856</strong>-31.0581.png <a href="http://soundexpert.org/documents/10179/1964064/(12) ULN8 3D into itself.wav(44)__Original2.flac(44)__mono_400-53.3282-43.1856-31.0581.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(12) ULN8 3D into itself.wav(44)__Original2.flac(44)__mono_400-53.3282-43.1856-31.0581.png" width="60" /></a><br /> <em>Actualsizeaudio: 3.6 dB (L), 3.5 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> <br /> <strong>MOTU 2408mk3 [MOTU2408]</strong><br /> (13) Test Gerslutz - Motu 2408mk3.wav(44)__Original2.flac(44)__mono_400-53.2862<strong>-43.1806</strong>-31.0461.png <a href="http://soundexpert.org/documents/10179/1964064/(13) Test Gerslutz - Motu 2408mk3.wav(44)__Original2.flac(44)__mono_400-53.2862-43.1806-31.0461.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(13) Test Gerslutz - Motu 2408mk3.wav(44)__Original2.flac(44)__mono_400-53.2862-43.1806-31.0461.png" width="60" /></a><br /> <em>ram75: 0,1 dB (L), 0,1 dB (R) Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56,7 dBFS (L), -58,1 dBFS (R)</em><br /> <br /> <strong>MOTU 828 MkII [MOTU828]</strong><br /> (14) MOTU-828MK2_asym.wav(44)__Original2.flac(44)__mono_400-53.2686<strong>-43.2019</strong>-31.0492.png <a href="http://soundexpert.org/documents/10179/1964064/(14) MOTU-828MK2_asym.wav(44)__Original2.flac(44)__mono_400-53.2686-43.2019-31.0492.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(14) MOTU-828MK2_asym.wav(44)__Original2.flac(44)__mono_400-53.2686-43.2019-31.0492.png" width="60" /></a><br /> <em>laurend: 6.1 dB (L), 6.2 dB (R) Corr Depth: 36,4 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L) -58.0 dBFS (R)</em><br /> (15) Original on motu 828 mkii via audiodesk.wav(44)__Original2.flac(44)__mono_400-53.3170<strong>-43.1817</strong>-7.6998.png <a href="http://soundexpert.org/documents/10179/1964064/(15) Original on motu 828 mkii via audiodesk.wav(44)__Original2.flac(44)__mono_400-53.3170-43.1817-7.6998.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(15) Original on motu 828 mkii via audiodesk.wav(44)__Original2.flac(44)__mono_400-53.3170-43.1817-7.6998.png" width="60" /></a><br /> <em>capn357 0.1 dB (L), 0.1 dB (R)..Corr Depth: 36,4 dB (L), 38,0 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> (16) Motu 828 Mk2.wav(44)__Original2.flac(44)__mono_400-53.2625<strong>-43.1788</strong>-31.0654.png <a href="http://soundexpert.org/documents/10179/1964064/(16) Motu 828 Mk2.wav(44)__Original2.flac(44)__mono_400-53.2625-43.1788-31.0654.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(16) Motu 828 Mk2.wav(44)__Original2.flac(44)__mono_400-53.2625-43.1788-31.0654.png" width="60" /></a><br /> <em>Xav: 0.1 dB (L), 0.1 dB (R), Difference: -56.7 dBFS (L), -58.1 dBFS (R) </em><br /> <br /> <strong>MOTU 24I/O [MOTU24]</strong><br /> (17) Motu24ioZAM.wav(44)__Original2.flac(44)__mono_400-53.2896<strong>-43.1794</strong>-31.0378.png <a href="http://soundexpert.org/documents/10179/1964064/(17) Motu24ioZAM.wav(44)__Original2.flac(44)__mono_400-53.2896-43.1794-31.0378.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(17) Motu24ioZAM.wav(44)__Original2.flac(44)__mono_400-53.2896-43.1794-31.0378.png" width="60" /></a><br /> <em>Zam on Pragmatic Audio: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.0 dBFS (R)</em><br /> (18) Test Gerslutz - Motu 24 io.wav(44)__Original2.flac(44)__mono_400-53.3119<strong>-43.1774</strong>-31.0601.png <a href="http://soundexpert.org/documents/10179/1964064/(18) Test Gerslutz - Motu 24 io.wav(44)__Original2.flac(44)__mono_400-53.3119-43.1774-31.0601.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(18) Test Gerslutz - Motu 24 io.wav(44)__Original2.flac(44)__mono_400-53.3119-43.1774-31.0601.png" width="60" /></a><br /> <em>ram75: 0.1 dB (L), 0.1 dB (R) Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> <br /> <strong>Mytek 8 x 192 AD/DA [Mytek8]</strong><br /> (19) Mytek.wav(44)__Original2.flac(44)__mono_400-52.7958<strong>-42.2019</strong>-29.8534.png <a href="http://soundexpert.org/documents/10179/1964064/(19) Mytek.wav(44)__Original2.flac(44)__mono_400-52.7958-42.2019-29.8534.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(19) Mytek.wav(44)__Original2.flac(44)__mono_400-52.7958-42.2019-29.8534.png" width="60" /></a><br /> <em>MainTime: 0.4 dB (L), 0.5 dB (R) Corr Depth: 35,3 dB (L), 36,9 dB (R) Difference: -55.8 dBFS (L) -57.1 dBFS (R)</em><br /> (20) Diffmaker_1stPass-Mytek-Master.wav(44)__Original2.flac(44)__mono_400-53.3219<strong>-42.7225</strong>-30.4273.png <a href="http://soundexpert.org/documents/10179/1964064/(20) Diffmaker_1stPass-Mytek-Master.wav(44)__Original2.flac(44)__mono_400-53.3219-42.7225-30.4273.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(20) Diffmaker_1stPass-Mytek-Master.wav(44)__Original2.flac(44)__mono_400-53.3219-42.7225-30.4273.png" width="60" /></a><br /> <em>mudseason: -0.1 dB (L), -0.1 dB (R)..Corr Depth: 35,8 dB (L), 37,4 dB (R) Difference: -56.3 dBFS (L), -57.7 dBFS (R)</em><br /> <br /> <strong>Genex GXD8 ---> Genex GXA8 [Genex]</strong><br /> (21) Antoine+Fabi+Null+files+test+export+Genex+GXD8-GXA8_01.wav(44)__Original2.flac(44)__mono_400-49.9898<strong>-41.8332</strong>-28.5405.png <a href="http://soundexpert.org/documents/10179/1964064/%2821%29%2520Antoine%252BFabi%252BNull%252Bfiles%252Btest%252Bexport%252BGenex%252BGXD8-GXA8_01.wav%2844%29__Original2.flac%2844%29__mono_400-49.9898-41.8332-28.5405.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%2821%29%2520Antoine%252BFabi%252BNull%252Bfiles%252Btest%252Bexport%252BGenex%252BGXD8-GXA8_01.wav%2844%29__Original2.flac%2844%29__mono_400-49.9898-41.8332-28.5405.png" width="60" /></a><br /> <em>Antoine Fabi, 0.1 dB (L), 0.1 dB (R)..Corr Depth: 35,1 dB (L), 36,3 dB (R) Difference: -55.7 dBFS (L), -55.7 dBFS (R)</em><br /> <br /> <strong>Antelope Audio Zen Tour [ZenTour]</strong><br /> (22) Antelope audio Zen Tour monitor out ot line in.wav(44)__Original2.flac(44)__mono_400-51.6680<strong>-41.3784</strong>-29.2356.png <a href="http://soundexpert.org/documents/10179/1964064/(22) Antelope audio Zen Tour monitor out ot line in.wav(44)__Original2.flac(44)__mono_400-51.6680-41.3784-29.2356.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(22) Antelope audio Zen Tour monitor out ot line in.wav(44)__Original2.flac(44)__mono_400-51.6680-41.3784-29.2356.png" width="60" /></a><br /> <em>esldude: 0.5 dB (L), 0.6 dB (R)..Corr Depth: 34,5 dB (L), 36,1 dB (R) Difference: -55.0 dBFS (L), -56.3 dBFS (R)</em><br /> (23) ZenTour_by_Zek_441_24_MBP_TB_LogicX.wav(44)__Original2.flac(44)__mono_400-48.5301<strong>-39.9814</strong>-29.2276.png <a href="http://soundexpert.org/documents/10179/1964064/(23) ZenTour_by_Zek_441_24_MBP_TB_LogicX.wav(44)__Original2.flac(44)__mono_400-48.5301-39.9814-29.2276.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(23) ZenTour_by_Zek_441_24_MBP_TB_LogicX.wav(44)__Original2.flac(44)__mono_400-48.5301-39.9814-29.2276.png" width="60" /></a><br /> <em>Zek: 0.9 dB (L), 1.0 dB (R)..Corr Depth: 34,9 dB (L), 36,5 dB (R) Difference: -49.8 dBFS (L), -50.8 dBFS (R)</em><br /> <br /> <strong>Lynx Aurora 8 [Aurora8]</strong><br /> (24) aurora8.wav(44)__Original2.flac(44)__mono_400-47.5606<strong>-41.0884</strong>-29.3425.png <a href="http://soundexpert.org/documents/10179/1964064/(24) aurora8.wav(44)__Original2.flac(44)__mono_400-47.5606-41.0884-29.3425.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(24) aurora8.wav(44)__Original2.flac(44)__mono_400-47.5606-41.0884-29.3425.png" width="60" /></a><br /> <em>cylens: -0,1 dB (L), -0,1 dB (R) Corr Depth: 34,6 dB (L), 36,3 dB (R) Difference: -54.5 dBFS (L) -55.6 dBFS (R)</em><br /> <br /> <strong>Lynx Aurora 16 [Aurora16]</strong><br /> (25) aurora 15-16.wav(44)__Original2.flac(44)__mono_400-47.5420<strong>-41.0741</strong>-29.3492.png <a href="http://soundexpert.org/documents/10179/1964064/(25) aurora 15-16.wav(44)__Original2.flac(44)__mono_400-47.5420-41.0741-29.3492.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(25) aurora 15-16.wav(44)__Original2.flac(44)__mono_400-47.5420-41.0741-29.3492.png" width="60" /></a><br /> <em>Touf on Pragmatic Audio: -0.1dB (L), -0.1dB (R)..Corr Depth: 34,6 dB (L), 36,3 dB (R) Difference: -54.5 dBFS (L), -55.6 dBFS (R)</em><br /> (26) LynxAurora16-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.5253<strong>-41.0264</strong>-29.3275.png <a href="http://soundexpert.org/documents/10179/1964064/(26) LynxAurora16-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.5253-41.0264-29.3275.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(26) LynxAurora16-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.5253-41.0264-29.3275.png" width="60" /></a><br /> <em>antichef: -0,1 dB (L), -0,1 dB (R)..Corr Depth: 34,6 dB (L), 36,2 dB (R) Difference: -54.5 dBFS (L), -55.5 dBFS (R)</em><br /> <br /> <strong>Edirol UA-1000 [UA1000]</strong><br /> (27) UA1000_ADDALoop.wav(44)__Original2.flac(44)__mono_400-50.9862<strong>-40.9063</strong>-28.8023.png <a href="http://soundexpert.org/documents/10179/1964064/(27) UA1000_ADDALoop.wav(44)__Original2.flac(44)__mono_400-50.9862-40.9063-28.8023.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(27) UA1000_ADDALoop.wav(44)__Original2.flac(44)__mono_400-50.9862-40.9063-28.8023.png" width="60" /></a><br /> <em>gollumsluvslave: 0.2 dB (L), 0.2 dB (R) Corr Depth: 34,0 dB (L), 35,6 dB (R) Difference: -54.4 dBFS (L), -55.7 dBFS (R)</em><br /> <br /> <strong>RME ADI-2 Pro [ADI2pro]</strong>; balanced out to balanced in, LesC:<br /> (28) Sharp_In_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-49.5137<strong>-40.3876</strong>-28.4300.png <a href="http://soundexpert.org/documents/10179/1964064/(28) Sharp_In_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-49.5137-40.3876-28.4300.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(28) Sharp_In_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-49.5137-40.3876-28.4300.png" width="60" /></a><br /> <em>Sharp DA - Sharp AD: 0.4 dB (L), 0.4 dB (R)..Corr Depth: 33,6 dB (L), 35,2 dB (R) Difference: -53.9 dBFS (L), -55.2 dBFS (R)</em><br /> (29) Slow_In_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-50.1182<strong>-40.1368</strong>-28.4093.png <a href="http://soundexpert.org/documents/10179/1964064/(29) Slow_In_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-50.1182-40.1368-28.4093.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(29) Slow_In_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-50.1182-40.1368-28.4093.png" width="60" /></a><br /> <em>Slow DA - Slow AD: 0.4 dB (L), 0.3 dB (R)..Corr Depth: 33,6 dB (L), 35,2 dB (R) Difference: -52.8 dBFS (L), -54.3 dBFS (R)</em><br /> (30) SD_Sharp_In_SD_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-45.4782<strong>-36.8381</strong>-22.8101.png <a href="http://soundexpert.org/documents/10179/1964064/(30) SD_Sharp_In_SD_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-45.4782-36.8381-22.8101.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(30) SD_Sharp_In_SD_Sharp_Out_01.wav(44)__Original2.flac(44)__mono_400-45.4782-36.8381-22.8101.png" width="60" /></a><br /> <em>SD Sharp DA - SD Sharp AD: 0.4 dB (L), 0.4 dB (R)..Corr Depth: 33,6 dB (L), 35,3 dB (R) Difference: -44.5 dBFS (L), -45.5 dBFS (R)</em><br /> (31) SD_Slow_In_SD_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-47.1014<strong>-38.3156</strong>-27.1622.png <a href="http://soundexpert.org/documents/10179/1964064/(31) SD_Slow_In_SD_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-47.1014-38.3156-27.1622.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(31) SD_Slow_In_SD_Slow_Out_01.wav(44)__Original2.flac(44)__mono_400-47.1014-38.3156-27.1622.png" width="60" /></a><br /> <em>SD Slow DA - SD slow AD: 0.3 dB (L), 0.3 dB (R)..Corr Depth: 33,6 dB (L), 35,2 dB (R) Difference: -47.9 dBFS (L), -48.9 dBFS (R)</em><br /> <br /> <strong>RME ADI-2 Pro FS [ADI2proFS]</strong><br /> (32) Symphonic Test Original2 Recorded2.wav(44)__Original2.flac(44)__mono_400-45.2067<strong>-36.6806</strong>-22.7762.png <a href="http://soundexpert.org/documents/10179/1964064/(32) Symphonic Test Original2 Recorded2.wav(44)__Original2.flac(44)__mono_400-45.2067-36.6806-22.7762.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(32) Symphonic Test Original2 Recorded2.wav(44)__Original2.flac(44)__mono_400-45.2067-36.6806-22.7762.png" width="60" /></a><br /> <em>Archimago, unspecified setting, XLR loopback: 0,2 dB (L), 0,2 dB (R)..Corr Depth: 33,6 dB (L), 35,1 dB (R) Difference: -44.3 dBFS (L), -45.4 dBFS (R)</em><br /> <br /> <strong>Alesis io|26 [io|26]</strong><br /> (33) Alesis_IO26_dffmkr.wav(44)__Original2.flac(44)__mono_400-46.9432<strong>-40.4941</strong>-28.6575.png <a href="http://soundexpert.org/documents/10179/1964064/(33) Alesis_IO26_dffmkr.wav(44)__Original2.flac(44)__mono_400-46.9432-40.4941-28.6575.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(33) Alesis_IO26_dffmkr.wav(44)__Original2.flac(44)__mono_400-46.9432-40.4941-28.6575.png" width="60" /></a><br /> <em>mistergo: 0.7 dB (L), 0.7 dB (R)..Corr Depth: 33,9 dB (L), 35,6 dB (R) Difference: -53.9 dBFS (L), -55.0 dBFS (R)</em><br /> <br /> <strong>TC Electronic Studio Konnekt 48 [Konnect48]</strong><br /> (34) Konnekt 48.wav(44)__Original2.flac(44)__mono_400-49.6459<strong>-40.0358</strong>-27.8441.png <a href="http://soundexpert.org/documents/10179/1964064/(34) Konnekt 48.wav(44)__Original2.flac(44)__mono_400-49.6459-40.0358-27.8441.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(34) Konnekt 48.wav(44)__Original2.flac(44)__mono_400-49.6459-40.0358-27.8441.png" width="60" /></a><br /> <em>DownSideUp: 13.1 dB (L), 13.2 dB (R)..Corr Depth: 33,2 dB (L), 34,8 dB (R) Difference: -53.6 dBFS (L) -54.9 dBFS (R)</em><br /> <br /> <strong>Lynx L22 [L22]</strong><br /> (35) L22 .wav(44)__Original2.flac(44)__mono_400-50.0323<strong>-39.9022</strong>-27.9136.png <a href="http://soundexpert.org/documents/10179/1964064/(35) L22 .wav(44)__Original2.flac(44)__mono_400-50.0323-39.9022-27.9136.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(35) L22 .wav(44)__Original2.flac(44)__mono_400-50.0323-39.9022-27.9136.png" width="60" /></a><br /> <em>bezen4uk: 2.9 dB (L), 2.9 dB (R)..Corr Depth: 33,0 dB (L), 34,7 dB (R) Difference: -53.5 dBFS (L), -54.7 dBFS (R)</em><br /> <br /> <strong>Lynx LynxTWO-B [LynxTwoB]</strong><br /> (36) Lynx Two B.wav(44)__Original2.flac(44)__mono_400-49.7488<strong>-39.5993</strong>-27.6120.png <a href="http://soundexpert.org/documents/10179/1964064/(36) Lynx Two B.wav(44)__Original2.flac(44)__mono_400-49.7488-39.5993-27.6120.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(36) Lynx Two B.wav(44)__Original2.flac(44)__mono_400-49.7488-39.5993-27.6120.png" width="60" /></a><br /> <em>bezen4uk: 2.8 dB (L), 2.8 dB (R) Corr Depth: 32,7 dB (L), 34,3 dB (R) Difference: -53.2 dBFS (L) , -54.5 dBFS (R)</em><br /> (37) LynxTWOB_ReRecordedStereo.wav(44)__Original2.flac(44)__mono_400-49.9288<strong>-39.8042</strong>-27.8054.png <a href="http://soundexpert.org/documents/10179/1964064/(37) LynxTWOB_ReRecordedStereo.wav(44)__Original2.flac(44)__mono_400-49.9288-39.8042-27.8054.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(37) LynxTWOB_ReRecordedStereo.wav(44)__Original2.flac(44)__mono_400-49.9288-39.8042-27.8054.png" width="60" /></a><br /> <em>mattiasnyc: -0.0 dB (L), -0.0 dB (R) Corr Depth: 32,9 dB (L), 34,5 dB (R) Difference: -53.4 dBFS (L) , -54.7 dBFS (R)</em><br /> <br /> <strong>ESI Juli@ XTe [Juli@XTe]</strong><br /> (38) Juli DAC - Juli ADC orig.wav(44)__Original2.flac(44)__mono_400-49.5268<strong>-39.5634</strong>-27.4983.png <a href="http://soundexpert.org/documents/10179/1964064/(38) Juli DAC - Juli ADC orig.wav(44)__Original2.flac(44)__mono_400-49.5268-39.5634-27.4983.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(38) Juli DAC - Juli ADC orig.wav(44)__Original2.flac(44)__mono_400-49.5268-39.5634-27.4983.png" width="60" /></a><br /> <em>DUJS: -0.3 dB (L), -0.3 dB (R) Corr Depth: 32,7 dB (L), 34,3 dB (R) Difference: -53.1 dBFS (L), -54.5 dBFS (R)</em><br /> <br /> <strong>Lynx E44 [E44]</strong><br /> (39) LynxE44.wav(44)__Original2.flac(44)__mono_400-46.5703<strong>-39.1125</strong>-27.2420.png <a href="http://soundexpert.org/documents/10179/1964064/(39) LynxE44.wav(44)__Original2.flac(44)__mono_400-46.5703-39.1125-27.2420.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(39) LynxE44.wav(44)__Original2.flac(44)__mono_400-46.5703-39.1125-27.2420.png" width="60" /></a><br /> <em>LTrain: -0.0 dB (L), -0.0 dB (R) Corr Depth: 32,3 dB (L), 34,1 dB (R) Difference: -52.5 dBFS (L), -53.9 dBFS (R)</em><br /> (40) LynxE44(1).wav(44)__Original2.flac(44)__mono_400-46.5703<strong>-39.1125</strong>-27.2420.png <a href="http://soundexpert.org/documents/10179/1964064/(40) LynxE44(1).wav(44)__Original2.flac(44)__mono_400-46.5703-39.1125-27.2420.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(40) LynxE44(1).wav(44)__Original2.flac(44)__mono_400-46.5703-39.1125-27.2420.png" width="60" /></a><br /> <em>Zek: -0.1 dB (L), -0.1 dB (R)..Corr Depth: 32,1 dB (L), 33,8 dB (R) Difference: -52.4 dBFS (L), -53.6 dBFS (R)</em><br /> <br /> <strong>RME HDSP 9632 [HDSP9632]</strong><br /> (41) RME HDSP 9632.wav(44)__Original2.flac(44)__mono_400-48.4058<strong>-38.3167</strong>-26.2809.png <a href="http://soundexpert.org/documents/10179/1964064/(41) RME HDSP 9632.wav(44)__Original2.flac(44)__mono_400-48.4058-38.3167-26.2809.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(41) RME HDSP 9632.wav(44)__Original2.flac(44)__mono_400-48.4058-38.3167-26.2809.png" width="60" /></a><br /> <em>schtim: 0.5 dB (L), 0.5 dB (R) Corr Depth: 31.4 dB (L), 33.0 dB (R) Difference: -51.9 dBFS (L) -53.2 dBFS (R)</em><br /> <br /> <strong>RME ADI-8 QS [ADI8QS]</strong><br /> (42) Original2_RME_ADI-8QS_0dB.wav(44)__Original2.flac(44)__mono_400-46.2096<strong>-38.1523</strong>-26.1437.png <a href="http://soundexpert.org/documents/10179/1964064/(42) Original2_RME_ADI-8QS_0dB.wav(44)__Original2.flac(44)__mono_400-46.2096-38.1523-26.1437.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(42) Original2_RME_ADI-8QS_0dB.wav(44)__Original2.flac(44)__mono_400-46.2096-38.1523-26.1437.png" width="60" /></a><br /> <em>lou latch: 0.0 dB (L), 0.0 dB (R) Corr Depth: 31,4 dB (L), 32,9 dB (R) Difference: -51.7 dBFS (L), -52.7 dBFS (R)</em><br /> <br /> <strong>Audient iD22 [iD22]</strong>, through insert returns<br /> (43) Audient iD22 Ins.-Return.wav(44)__Original2.flac(44)__mono_400-34.6431<strong>-32.5718</strong>-25.4513.png <a href="http://soundexpert.org/documents/10179/1964064/%2843%29%20Audient+iD22+Ins.-Return.wav%2844%29__Original2.flac%2844%29__mono_400-34.6431-32.5718-25.4513.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" src="http://soundexpert.org/documents/10179/1964064/%2843%29%20Audient+iD22+Ins.-Return.wav%2844%29__Original2.flac%2844%29__mono_400-34.6431-32.5718-25.4513.png/2e1dcf20-e34f-4e22-ab5a-321b857762ae?t=1590515645000" style="width: 60px; height: 20px;" /></a><br /> <em>andyfromHH: 0.0 dB (L), 0.1 dB (R) Corr Depth: 32,4 dB (L), 34,3 dB (R) Difference: -45.4 dBFS (L), -46.6 dBFS (R)</em><br /> (44) ID22 Output 1#2 into inserts loopback.wav(44)__Original2.flac(44)__mono_400-48.1521<strong>-38.0959</strong>-26.0966.png <a href="http://soundexpert.org/documents/10179/1964064/%2844%29%20ID22%20Output%201%252B2%20into%20inserts%20loopback.wav%2844%29__Original2.flac%2844%29__mono_400-48.1521-38.0959-26.0966.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%2844%29%20ID22%20Output%201%252B2%20into%20inserts%20loopback.wav%2844%29__Original2.flac%2844%29__mono_400-48.1521-38.0959-26.0966.png" width="60" /></a><br /> <em>SM5, out 1-2: 1.2 dB (L), 0.1 dB (R)..Corr Depth: 24,4 dB (L), 30,5 dB (R) Difference: -51.7 dBFS (L), -53.0 dBFS (R)</em><br /> (45) ID22 Output 3#4 into inserts looback.wav(44)__Original2.flac(44)__mono_400-48.0789<strong>-38.0148</strong>-26.0219.png <a href="http://soundexpert.org/documents/10179/1964064/%2845%29%20ID22%20Output%203%252B4%20into%20inserts%20looback.wav%2844%29__Original2.flac%2844%29__mono_400-48.0789-38.0148-26.0219.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%2845%29%20ID22%20Output%203%252B4%20into%20inserts%20looback.wav%2844%29__Original2.flac%2844%29__mono_400-48.0789-38.0148-26.0219.png" width="60" /></a><br /> <em>Out 3-4: 0.2 dB (L), 0.2 dB (R)..Corr Depth: 31,2 dB (L), 32,7 dB (R) Difference: -51.6 dBFS (R), -52.9 dBFS (L)</em><br /> (46) ID22-To-ID22.wav(44)__Original2.flac(44)__mono_400-48.1484<strong>-38.1157</strong>-26.1407.png <a href="http://soundexpert.org/documents/10179/1964064/(46) ID22-To-ID22.wav(44)__Original2.flac(44)__mono_400-48.1484-38.1157-26.1407.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(46) ID22-To-ID22.wav(44)__Original2.flac(44)__mono_400-48.1484-38.1157-26.1407.png" width="60" /></a><br /> <em>feutche: 0.9 dB (L), 0.9 dB (R)..Corr Depth: 31,3 dB (L), 32,8 dB (R) Difference: -51.7 dBFS (L), -53.0 dBFS (R)</em><br /> <br /> <strong>Prism Lyra 1 [Lyra1]</strong><br /> (47) Original2viaLyra1.wav(44)__Original2.flac(44)__mono_400-46.2658<strong>-38.1594</strong>-25.9560.png <a href="http://soundexpert.org/documents/10179/1964064/(47) Original2viaLyra1.wav(44)__Original2.flac(44)__mono_400-46.2658-38.1594-25.9560.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(47) Original2viaLyra1.wav(44)__Original2.flac(44)__mono_400-46.2658-38.1594-25.9560.png" width="60" /></a><br /> <em>capn357: 0,0 dB (L), -0,0 dB (R)..Corr Depth: 31,3 dB (L), 33,1 dB (R) Difference: -51.6 dBFS (L), -53.0 dBFS (R)</em><br /> <br /> <strong>Prism Lyra 2 [Lyra2]</strong><br /> (48) Lyra 2.wav(44)__Original2.flac(44)__mono_400-46.0977<strong>-37.8009</strong>-25.6026.png <a href="http://soundexpert.org/documents/10179/1964064/(48) Lyra 2.wav(44)__Original2.flac(44)__mono_400-46.0977-37.8009-25.6026.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(48) Lyra 2.wav(44)__Original2.flac(44)__mono_400-46.0977-37.8009-25.6026.png" width="60" /></a><br /> <em>Shptq: 0,0 dB (L), -0,0 dB (R)..Corr Depth: 31,0 dB (L), 32,6 dB (R) Difference: -51.3 dBFS (L), -52.6 dBFS (R)</em><br /> <br /> <strong>Prism Orpheus [Orpheus]</strong><br /> (49) Prism.wav(44)__Original2.flac(44)__mono_400-46.0695<strong>-37.6642</strong>-25.4469.png <a href="http://soundexpert.org/documents/10179/1964064/(49) Prism.wav(44)__Original2.flac(44)__mono_400-46.0695-37.6642-25.4469.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(49) Prism.wav(44)__Original2.flac(44)__mono_400-46.0695-37.6642-25.4469.png" width="60" /></a><br /> <em>MainTime: 0,1 dB (L), 0,1 dB (R) Corr Depth: 30,8 dB (L), 32,4 dB (R) Difference: -51.1 dBFS (L) -52.4 dBFS (R)</em><br /> <br /> <strong>Digidesign Digi 002 Rack with Black Lion Audio Signature mod [Digi002R]</strong><br /> (50) Black Lion Audio Modified - Digidesign 002R Signature Series.wav(44)__Original2.flac(44)__mono_400-47.4915<strong>-37.3016</strong>-25.2836.png <a href="http://soundexpert.org/documents/10179/1964064/(50) Black Lion Audio Modified - Digidesign 002R Signature Series.wav(44)__Original2.flac(44)__mono_400-47.4915-37.3016-25.2836.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(50) Black Lion Audio Modified - Digidesign 002R Signature Series.wav(44)__Original2.flac(44)__mono_400-47.4915-37.3016-25.2836.png" width="60" /></a><br /> <em>jlam, Line Out 7+8 to Line In 7+8: 0.3 dB (L), 0.4 dB (R)..Corr Depth: 30,3 dB (L), 32,1 dB (R) Difference: -50.7 dBFS (L), -52.1 dBFS (R)</em><br /> <br /> <strong>Universal Audio Apollo 16 mkII [Apollo16]</strong><br /> (51) Apollo16mkii-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.4061<strong>-37.1144</strong>-25.0148.png <a href="http://soundexpert.org/documents/10179/1964064/(51) Apollo16mkii-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.4061-37.1144-25.0148.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(51) Apollo16mkii-InternalClock.wav(44)__Original2.flac(44)__mono_400-47.4061-37.1144-25.0148.png" width="60" /></a><br /> <em>antichef: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 30,2 dB (L), 31,8 dB (R) Difference: -50.7 dBFS (L) , -52.1 dBFS (R)</em><br /> <br /> <strong>RME Fireface 400 [Fireface400]</strong><br /> (52) Fireface400.wav(44)__Original2.flac(44)__mono_400-47.0812<strong>-37.0849</strong>-25.2116.png <a href="http://soundexpert.org/documents/10179/1964064/(52) Fireface400.wav(44)__Original2.flac(44)__mono_400-47.0812-37.0849-25.2116.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(52) Fireface400.wav(44)__Original2.flac(44)__mono_400-47.0812-37.0849-25.2116.png" width="60" /></a><br /> <em>didier.brest: 0.3 dB (L), 0.3 dB (R) Corr Depth: 30,2 dB (L), 31,8 dB (R) Difference: -50.7 dBFS (L), 52.0 dBFS (R)</em><br /> <br /> <strong>Merging Anubis Pro [Anubis]</strong><br /> (53) Zek_Merging_Anubis.wav(44)__Original2.flac(44)__mono_400-49.6709<strong>-41.7906</strong>-29.5312.png <a href="http://soundexpert.org/documents/10179/1964064/(53) Zek_Merging_Anubis.wav(44)__Original2.flac(44)__mono_400-49.6709-41.7906-29.5312.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(53) Zek_Merging_Anubis.wav(44)__Original2.flac(44)__mono_400-49.6709-41.7906-29.5312.png" width="60" /></a><br /> <em>Zek, DA filter set to Slow: 0.6 dB (L), 0.6 dB (R)..Corr Depth: 37,5 dB (L), 39,2 dB [/URL](R) Difference: -50.5 dBFS (L), -51.5 dBFS (R)</em><br /> (54) Zek_Merging_Anubis_DA-sharp.wav(44)__Original2.flac(44)__mono_400-49.7033<strong>-41.6968</strong>-29.2822.png <a href="http://soundexpert.org/documents/10179/1964064/(54) Zek_Merging_Anubis_DA-sharp.wav(44)__Original2.flac(44)__mono_400-49.7033-41.6968-29.2822.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(54) Zek_Merging_Anubis_DA-sharp.wav(44)__Original2.flac(44)__mono_400-49.7033-41.6968-29.2822.png" width="60" /></a><br /> <em>Zek, DA filter set to Sharp: 0.6 dB (L), 0,6 dB (R)..Corr Depth: 37,4 dB (L), 39,1 dB (R) Difference: -50.3 dBFS (L), -51.3 dBFS (R)</em><br /> <br /> <strong>MOTU Track16 [MOTUTrack16]</strong><br /> (55) Track16 playback.wav(44)__Original2.flac(44)__mono_400-45.6687<strong>-36.8370</strong>-24.8288.png <a href="http://soundexpert.org/documents/10179/1964064/(55) Track16 playback.wav(44)__Original2.flac(44)__mono_400-45.6687-36.8370-24.8288.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(55) Track16 playback.wav(44)__Original2.flac(44)__mono_400-45.6687-36.8370-24.8288.png" width="60" /></a><br /> <em>EvgenyStudio: 7.0 dB (L), 6.9 dB Corr Depth: 30,0 dB (L), 31,5 dB (R) Difference: -50,4 dBFS (L), -51,6 dBFS (R)</em><br /> <br /> <strong>Forssell MADA-2 [MADA2]</strong><br /> (56) AuDirFor_loopXLR_ForDirAu_MasForWC.wav(44)__Original2.flac(44)__mono_400-46.2577<strong>-36.5031</strong>-21.9876.png <a href="http://soundexpert.org/documents/10179/1964064/(56) AuDirFor_loopXLR_ForDirAu_MasForWC.wav(44)__Original2.flac(44)__mono_400-46.2577-36.5031-21.9876.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(56) AuDirFor_loopXLR_ForDirAu_MasForWC.wav(44)__Original2.flac(44)__mono_400-46.2577-36.5031-21.9876.png" width="60" /></a><br /> <em>Mikathechou (DA converters upgraded to 2a version): 1.0 dB (L), 1.0 dB (R)..Corr Depth: 29,7 dB (L), 31,3 dB (R) Difference: -50.1 dBFS (L), -51.5 dBFS (R)</em><br /> <br /> <strong>Apogee Symphony I/O [Symphony]</strong><br /> (57) Apogee Symphony IO 1x loopback.wav(44)__Original2.flac(44)__mono_400-45.1603<strong>-38.4330</strong>-33.6970.png <a href="http://soundexpert.org/documents/10179/1964064/(57) Apogee Symphony IO 1x loopback.wav(44)__Original2.flac(44)__mono_400-45.1603-38.4330-33.6970.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(57) Apogee Symphony IO 1x loopback.wav(44)__Original2.flac(44)__mono_400-45.1603-38.4330-33.6970.png" width="60" /></a><br /> <em>Ajantis: 0,0 dB (L), 0,0 dB (R) Corr Depth: 43,4 dB (L), 45,6 dB (R) Difference: -51,2 dBFS (L), -50,1 dBFS dB (R)</em><br /> (58) Symphony mki -.2.wav(44)__Original2.flac(44)__mono_400-45.1627<strong>-38.4330</strong>-33.6970.png <a href="http://soundexpert.org/documents/10179/1964064/(58) Symphony mki -.2.wav(44)__Original2.flac(44)__mono_400-45.1627-38.4330-33.6970.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(58) Symphony mki -.2.wav(44)__Original2.flac(44)__mono_400-45.1627-38.4330-33.6970.png" width="60" /></a><br /> <em>Diegel -0.2 dB (L), -0.1 dB (R)..Corr Depth: 43,4 dB (L), 45,6 dB (R) Difference: -51.1 dBFS (L), -50.1 dBFS (R)</em><br /> <br /> <strong>MOTU 624 [MOTU624]</strong><br /> (59) 624-0+2_LoopBack.wav(44)__Original2.flac(44)__mono_400-45.1633<strong>-38.4298</strong>-33.6949.png <a href="http://soundexpert.org/documents/10179/1964064/%2859%29%20624-0%252B2_LoopBack.wav%2844%29__Original2.flac%2844%29__mono_400-45.1633-38.4298-33.6949.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%2859%29%20624-0%252B2_LoopBack.wav%2844%29__Original2.flac%2844%29__mono_400-45.1633-38.4298-33.6949.png" width="60" /></a><br /> <em>EdwardZ7, 0dB output and +2dB input: 0.0 dB (L), -0.0 dB (R)..Corr Depth: 43,4 dB (L), 45,6 dB (R) Difference: -51.1 dBFS (L), -50.1 dBFS (R)</em><br /> <br /> <strong>MOTU 16A [MOTU16A]</strong><br /> (60) MOTU 16a Loop Test_correctstereo.wav(44)__Original2.flac(44)__mono_400-45.1778<strong>-38.4048</strong>-33.6922.png <a href="http://soundexpert.org/documents/10179/1964064/(60) MOTU 16a Loop Test_correctstereo.wav(44)__Original2.flac(44)__mono_400-45.1778-38.4048-33.6922.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(60) MOTU 16a Loop Test_correctstereo.wav(44)__Original2.flac(44)__mono_400-45.1778-38.4048-33.6922.png" width="60" /></a><br /> <em>davidbayles: 1.518 dB (L) 1.513 dB (R) Corr Depth: 43,4 dB (L), 45,6 dB (R) Difference: -51.1 dBFS (L), -50.1 dBFS (R)</em><br /> <br /> <strong>MOTU 8A [MOTU8A]</strong><br /> (61) Motu8a-IN_Out_5-6_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.1608<strong>-38.3798</strong>-0.3051.png <a href="http://soundexpert.org/documents/10179/1964064/(61) Motu8a-IN_Out_5-6_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.1608-38.3798-0.3051.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(61) Motu8a-IN_Out_5-6_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.1608-38.3798-0.3051.png" width="60" /></a><br /> <em>Zek: 1.2 dB (L), 1.1 dB (R)..Corr Depth: 43,4 dB (L), 45,7 dB (R) Difference: -51.1 dBFS (L), -50.0 dBFS (R)</em><br /> <br /> <strong>Apogee Rosetta 800 [Rosetta800]</strong><br /> (62) 7. Rosetta 800 clocked internally.wav(44)__Original2.flac(44)__mono_400-43.2383<strong>-38.2073</strong>-33.6892.png <a href="http://soundexpert.org/documents/10179/1964064/(62) 7. Rosetta 800 clocked internally.wav(44)__Original2.flac(44)__mono_400-43.2383-38.2073-33.6892.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(62) 7. Rosetta 800 clocked internally.wav(44)__Original2.flac(44)__mono_400-43.2383-38.2073-33.6892.png" width="60" /></a><br /> <em>davidbayle: 0.2 dB (L), 0.2 dB (R) Corr Depth: 39,7 dB (L), 41,7 dB (R) Difference: -50.0 dBFS (L), -50.9 dBFS (R)</em><br /> <br /> <strong>Apogee Rosetta 200 [Rosetta 200]</strong><br /> (63) Apogee Rosetta 200.wav(44)__Original2.flac(44)__mono_400-42.6982<strong>-37.9458</strong>-31.4866.png <a href="http://soundexpert.org/documents/10179/1964064/(63) Apogee Rosetta 200.wav(44)__Original2.flac(44)__mono_400-42.6982-37.9458-31.4866.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(63) Apogee Rosetta 200.wav(44)__Original2.flac(44)__mono_400-42.6982-37.9458-31.4866.png" width="60" /></a><br /> <em>Winston Tones: -0.1 dB (L), -0.0 dB (R) Corr Depth: 37,9 dB (L), 39,8 dB (R) Difference: -50.7 dB (L), -50.0 dB (R)</em><br /> <br /> <strong>Prism ADA-8XR [ADA8XR]</strong><br /> (64) Prism ADA-8XR shelterr (GearSlutz).wav(44)__Original2.flac(44)__mono_400-42.6357<strong>-37.8708</strong>-31.7659.png <a href="http://soundexpert.org/documents/10179/1964064/(64) Prism ADA-8XR shelterr (GearSlutz).wav(44)__Original2.flac(44)__mono_400-42.6357-37.8708-31.7659.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(64) Prism ADA-8XR shelterr (GearSlutz).wav(44)__Original2.flac(44)__mono_400-42.6357-37.8708-31.7659.png" width="60" /></a><br /> <em>shelterr: -0,03 dB (L), -0,03 dB (R) Corr Depth: 37,5 dB (L), 39,5 dB (R) Difference: -50,7 dBFS(L) -50,0 dBFS(R)</em><br /> <br /> <strong>Crane Song HEDD-92 [HEDD92]</strong><br /> (65) Original2 Hedd192.wav(44)__Original2.flac(44)__mono_400-42.4544<strong>-37.7163</strong>-30.9568.png <a href="http://soundexpert.org/documents/10179/1964064/(65) Original2 Hedd192.wav(44)__Original2.flac(44)__mono_400-42.4544-37.7163-30.9568.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(65) Original2 Hedd192.wav(44)__Original2.flac(44)__mono_400-42.4544-37.7163-30.9568.png" width="60" /></a><br /> <em>Spartacus: 0.5 dB (L), 0.5 dB (R) Corr Depth: 36,6 dB (L), 38,4 dB (R) Difference: -50.7 dBFS (L) , -50.0 dBFS (R)</em><br /> <br /> <strong>Antelope Orion Studio Rev2017 [OrionSt]</strong><br /> (66) OrionStudio2017_Line.wav(44)__Original2.flac(44)__mono_400-42.2637<strong>-33.1493</strong>-22.5125.png <a href="http://soundexpert.org/documents/10179/1964064/(66) OrionStudio2017_Line.wav(44)__Original2.flac(44)__mono_400-42.2637-33.1493-22.5125.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(66) OrionStudio2017_Line.wav(44)__Original2.flac(44)__mono_400-42.2637-33.1493-22.5125.png" width="60" /></a><br /> <em>jeamsler, Line Out to Line In: 1.3 dB (L), 1.3 dB (R)..Corr Depth: 27,7 dB (L), 29,3 dB (R) Difference: -43.6 dBFS (L), -44.8 dBFS (R)</em><br /> (67) OrionStudio2017_mon.wav(44)__Original2.flac(44)__mono_400-48.4554<strong>-39.9453</strong>-29.1500.png <a href="http://soundexpert.org/documents/10179/1964064/(67) OrionStudio2017_mon.wav(44)__Original2.flac(44)__mono_400-48.4554-39.9453-29.1500.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(67) OrionStudio2017_mon.wav(44)__Original2.flac(44)__mono_400-48.4554-39.9453-29.1500.png" width="60" /></a><br /> <em>jeamsler, Monitor Out to Line In: 1.3 dB (L), 1.3 dB (R)..Corr Depth: 34,8 dB (L), 36,4 dB (R) Difference: -49.9 dBFS (L), -50.9 dBFS (R)</em><br /> (68) OrionStudio2017_ReampLine.wav(44)__Original2.flac(44)__mono_400-23.8181<strong>-15.5390</strong>-7.4396.png <a href="http://soundexpert.org/documents/10179/1964064/(68) OrionStudio2017_ReampLine.wav(44)__Original2.flac(44)__mono_400-23.8181-15.5390-7.4396.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(68) OrionStudio2017_ReampLine.wav(44)__Original2.flac(44)__mono_400-23.8181-15.5390-7.4396.png" width="60" /></a><br /> <em>jeamsler, Reamp Out to Line In: 6.5 dB (L), 6.5 dB (R)..Corr Depth: 9,9 dB (L), 9,8 dB (R) Difference: -29.7 dBFS (L), -29.3 dBFS (R)</em><br /> <br /> <strong>TC Electronics Impact Twin [ImpactTwin]</strong><br /> (69) impcttwin.wav(44)__Original2.flac(44)__mono_400-49.0518<strong>-38.9224</strong>-26.8742.png <a href="http://soundexpert.org/documents/10179/1964064/(69) impcttwin.wav(44)__Original2.flac(44)__mono_400-49.0518-38.9224-26.8742.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(69) impcttwin.wav(44)__Original2.flac(44)__mono_400-49.0518-38.9224-26.8742.png" width="60" /></a><br /> <em>AndG: 0.5 dB (L), 0.8 dB (R) Corr Depth: 32,0 dB (L), 33,6 dB (R) Difference: -52.5 dBFS (L) -53.8 dBFS (R)</em><br /> (70) Tc Electronic Impact Twin No Clock Recovery.wav(44)__Original2.flac(44)__mono_400-45.8786<strong>-35.8268</strong>-23.8266.png <a href="http://soundexpert.org/documents/10179/1964064/(70) Tc Electronic Impact Twin No Clock Recovery.wav(44)__Original2.flac(44)__mono_400-45.8786-35.8268-23.8266.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(70) Tc Electronic Impact Twin No Clock Recovery.wav(44)__Original2.flac(44)__mono_400-45.8786-35.8268-23.8266.png" width="60" /></a><br /> <em>Coucou: -0.1 dB (L), -0.0 dB (R) Corr Depth: 29,1 dB (L), 30,4 dB (R) Difference: -49.5 dBFS (L), -50.5 dBFS (R)</em><br /> <br /> <strong>Echo Audiofire 12 [Audiofire12]</strong><br /> (71) audiofire12.wav(44)__Original2.flac(44)__mono_400-45.4815<strong>-35.5622</strong>-23.6896.png <a href="http://soundexpert.org/documents/10179/1964064/(71) audiofire12.wav(44)__Original2.flac(44)__mono_400-45.4815-35.5622-23.6896.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(71) audiofire12.wav(44)__Original2.flac(44)__mono_400-45.4815-35.5622-23.6896.png" width="60" /></a><br /> <em>guze: 0.7 dB (L), 0.7 dB (R) Corr Depth: 28,8 dB (L), 30,1 dB (R) Difference: -49.2 dBFS (L), -50.3 dBFS (R)</em><br /> <br /> <strong>PreSonus RML32AI [RML32AI]</strong><br /> (72) Presonus RML32AI.wav(44)__Original2.flac(44)__mono_400-45.3500<strong>-35.2659</strong>-23.4880.png <a href="http://soundexpert.org/documents/10179/1964064/(72) Presonus RML32AI.wav(44)__Original2.flac(44)__mono_400-45.3500-35.2659-23.4880.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(72) Presonus RML32AI.wav(44)__Original2.flac(44)__mono_400-45.3500-35.2659-23.4880.png" width="60" /></a><br /> <em>Xav: -0.8 dB (L), -0.7 dB (R)..Corr Depth: 28,4 dB (L), 30,0 dB (R) Difference: -48.8 dBFS (L), -50.1 dBFS (R)</em><br /> <br /> <strong>RME Babyface Pro [BabyfacePro]</strong><br /> (73) Babyface Pro XLR Out 1 2 - XLR In 1 2.wav(44)__Original2.flac(44)__mono_400-43.5304<strong>-33.3812</strong>-22.3842.png <a href="http://soundexpert.org/documents/10179/1964064/(73) Babyface Pro XLR Out 1 2 - XLR In 1 2.wav(44)__Original2.flac(44)__mono_400-43.5304-33.3812-22.3842.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(73) Babyface Pro XLR Out 1 2 - XLR In 1 2.wav(44)__Original2.flac(44)__mono_400-43.5304-33.3812-22.3842.png" width="60" /></a><br /> <em>EvgenyStudio, XLR out to XLR in: -0.1 dB (L), 0.1 dB (R)..Corr Depth: 24,9 dB (L), 32,9 dB (R) (L), Difference: -43.9 dBFS (L), -48.7 dBFS (R)</em><br /> (74) Babyface Pro Headphones out to Jacks In 3 4.wav(44)__Original2.flac(44)__mono_400-48.1970<strong>-39.6194</strong>-27.9806.png <a href="http://soundexpert.org/documents/10179/1964064/(74) Babyface Pro Headphones out to Jacks In 3 4.wav(44)__Original2.flac(44)__mono_400-48.1970-39.6194-27.9806.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(74) Babyface Pro Headphones out to Jacks In 3 4.wav(44)__Original2.flac(44)__mono_400-48.1970-39.6194-27.9806.png" width="60" /></a><br /> <em>EvgenyStudio, Headphone out to two TS line in: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 34,9 dB (L), 36,5 dB (R) Difference: -48.8 dBFS (L), -49.8 dBFS (R)</em><br /> <br /> <strong>Konnekt Live [KonnektLive]</strong><br /> (75) testfile-konnektlive-result.wav(44)__Original2.flac(44)__mono_400-45.0743<strong>-35.0466</strong>-23.2306.png <a href="http://soundexpert.org/documents/10179/1964064/(75) testfile-konnektlive-result.wav(44)__Original2.flac(44)__mono_400-45.0743-35.0466-23.2306.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(75) testfile-konnektlive-result.wav(44)__Original2.flac(44)__mono_400-45.0743-35.0466-23.2306.png" width="60" /></a><br /> <em>livebox: 7.0 dB (L), 7.0 dB (R)..Corr Depth: 28,2 dB (L), 29,7 dB (R) Difference: -48.6 dBFS (L), -50.0 dBFS (R)</em><br /> <br /> <strong>MOTU 828 mk3 hybrid [MOTU828h]</strong><br /> (76) MOTU828mk3.wav(44)__Original2.flac(44)__mono_400-40.6525<strong>-34.7967</strong>-24.3391.png<a href="https://www.gearslutz.com/board/gear.php?id=20788"> <img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(76) MOTU828mk3.wav(44)__Original2.flac(44)__mono_400-40.6525-34.7967-24.3391.png" width="60" /> </a><br /> <em>jeamsler: 3.5 dB (L), 3.5 dB (R) Corr Depth: 29,5 dB (L), 31,3 dB (R) Difference: -48.1 dBFS (L), -48.5 dBFS (R)</em><br /> <br /> <strong>Steinberg AXR4T [AXR4T]</strong><br /> (77) Zek_Steinberg_AXR4T_Front_inputs.wav(44)__Original2.flac(44)__mono_400-44.7193<strong>-34.6109</strong>-22.6434.png <a href="http://soundexpert.org/documents/10179/1964064/(77) Zek_Steinberg_AXR4T_Front_inputs.wav(44)__Original2.flac(44)__mono_400-44.7193-34.6109-22.6434.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(77) Zek_Steinberg_AXR4T_Front_inputs.wav(44)__Original2.flac(44)__mono_400-44.7193-34.6109-22.6434.png" width="60" /></a><br /> <em>Zek: 0.6 dB (L), 0.6 dB (R)..Corr Depth: 27,7 dB (L), 29,3 dB (R) Difference: -48.2 dBFS (L), -49.5 dBFS (R)</em><br /> <br /> <strong>Avid HD I/O 16x16 Analog [AvidHDI/O]</strong><br /> (78) Audio 1_01.LR.wav(44)__Original2.flac(44)__mono_400-40.3133<strong>-34.3106</strong>-23.5149.png <a href="http://soundexpert.org/documents/10179/1964064/%2878%29%20Audio+1_01.LR.wav%2844%29__Original2.flac%2844%29__mono_400-40.3133-34.3106-23.5149.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" src="http://soundexpert.org/documents/10179/1964064/%2878%29%20Audio+1_01.LR.wav%2844%29__Original2.flac%2844%29__mono_400-40.3133-34.3106-23.5149.png/1e739baa-ce22-46f6-bc3d-72b1da64a115?t=1590515826000" style="width: 60px; height: 20px;" /></a><br /> <em>Pezzn: -0,0 dB (L), -0,0 dB (R)..Corr Depth: 28,8 dB (L), 30,6 dB (R) Difference: -47.7 dBFS (L), -48.1 dBFS (R)</em><br /> <br /> <strong>SPL Madison [Madison]</strong><br /> (79) madison.wav(44)__Original2.flac(44)__mono_400-44.1609<strong>-34.0933</strong>-22.1970.png <a href="http://soundexpert.org/documents/10179/1964064/(79) madison.wav(44)__Original2.flac(44)__mono_400-44.1609-34.0933-22.1970.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(79) madison.wav(44)__Original2.flac(44)__mono_400-44.1609-34.0933-22.1970.png" width="60" /></a><br /> <em>funkakuchi on Pragmatic Audio: 0.0 dB (L), 0.1 dB (R)..Corr Depth: 27,2 dB (L), 28,8 dB (R) Difference: -47.7 dB (L), -49.0 dB (R)</em><br /> <br /> <strong>MOTU M4 [MOTUM4]</strong><br /> (80) Untitled_2#01.wav(44)__Original2.flac(44)__mono_400-44.0353<strong>-34.1933</strong>-22.6905.png <a href="http://soundexpert.org/documents/10179/1964064/(80) Untitled_2%2301.wav(44)__Original2.flac(44)__mono_400-44.0353-34.1933-22.6905.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(80) Untitled_2%2301.wav(44)__Original2.flac(44)__mono_400-44.0353-34.1933-22.6905.png" width="60" /></a><br /> <em>eigentone1: 2.5 dB (L), 2.5 dB (R)..Corr Depth: 27,4 dB (L), 28,9 dB (R) Difference: -47.7 dBFS (L), -49.0 dBFS</em><br /> <br /> <strong>SSL Alpha-Link MX 16\-4<a href="http://www.gearslutz.com/board/gear.php?id=23796" target="_blank"> </a>[MX164Xt64]</strong><br /> (81) Test 3.wav(44)__Original2.flac(44)__mono_400-44.1966<strong>-34.0953</strong>-22.3544.png <a href="http://soundexpert.org/documents/10179/1964064/(81) Test 3.wav(44)__Original2.flac(44)__mono_400-44.1966-34.0953-22.3544.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(81) Test 3.wav(44)__Original2.flac(44)__mono_400-44.1966-34.0953-22.3544.png" width="60" /></a><br /> <em>Sankly: 0,1 dB (L), 0,1 dB (R)..Corr Depth: 27,2 dB (L), 28,8 dB (R) Difference: -47.6 dBFS, -48.9 dBFS</em><br /> <br /> <strong>Yamaha MONTAGE 6 [MONTAGE6]</strong><br /> (82) Yamaha_Montage_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.6636<strong>-33.6954</strong>-21.8187.png <a href="http://soundexpert.org/documents/10179/1964064/(82) Yamaha_Montage_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.6636-33.6954-21.8187.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(82) Yamaha_Montage_by_Zek.wav(44)__Original2.flac(44)__mono_400-43.6636-33.6954-21.8187.png" width="60" /></a><br /> <em>Zek: 2.4 dB (L), 2.1 dB (R)..Corr Depth: 26,8 dB (L), 28,4 dB (R) Difference: -47.3 dBFS (L), -48.6 dBFS (R)</em><br /> <br /> <strong>Antelope Orion32 HD [Orion32HD]</strong><br /> (83) Orion 32HD into itself.wav(44)__Original2.flac(44)__mono_400-44.6330<strong>-35.3342</strong>-24.1835.png <a href="http://soundexpert.org/documents/10179/1964064/(83) Orion 32HD into itself.wav(44)__Original2.flac(44)__mono_400-44.6330-35.3342-24.1835.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(83) Orion 32HD into itself.wav(44)__Original2.flac(44)__mono_400-44.6330-35.3342-24.1835.png" width="60" /></a><br /> <em>Actualsizeaudio: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 29,4 dB (L), 31,0 dB (R) Difference: -46.8 dBFS (L), -47.9 dBFS (R)</em><br /> <br /> <strong>DAD AX24 [DADAX24]</strong><br /> (84) DAD.wav(44)__Original2.flac(44)__mono_400-39.5968<strong>-33.3542</strong>-22.1737.png <a href="http://soundexpert.org/documents/10179/1964064/(84) DAD.wav(44)__Original2.flac(44)__mono_400-39.5968-33.3542-22.1737.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(84) DAD.wav(44)__Original2.flac(44)__mono_400-39.5968-33.3542-22.1737.png" width="60" /></a><br /> <em>Norm@gear: -0,1 dB (L), -0,1 dB (R) Corr Depth: 27,4 dB (L), 28,9 dB (R) Difference: -46.8 dBFS (L), -47.3 dBFS (R)</em><br /> <br /> <strong>Behringer ADA8200 [ADA8200]</strong><br /> (85) BerhingerADA8200.wav(44)__Original2.flac(44)__mono_400-40.6054<strong>-33.8147</strong>-21.9460.png <a href="http://soundexpert.org/documents/10179/1964064/(85) BerhingerADA8200.wav(44)__Original2.flac(44)__mono_400-40.6054-33.8147-21.9460.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(85) BerhingerADA8200.wav(44)__Original2.flac(44)__mono_400-40.6054-33.8147-21.9460.png" width="60" /></a><br /> <em>didier.brest, gain @ 10 o'clock : 4.3 dB (L), 4.6 dB (R)..Corr Depth: 27,6 dB (L), 29,2 dB (R) Difference: -46.6 dBFS (L) , -47.7 dBFS (R)</em><br /> <br /> <strong>Echo AudioFire 4 [AudioFire4]</strong><br /> (86) Audiofire 4 output 3_4 to input 3_4.wav(44)__Original2.flac(44)__mono_400-42.5161<strong>-32.5905</strong>-21.2363.png <a href="http://soundexpert.org/documents/10179/1964064/(86) Audiofire 4 output 3_4 to input 3_4.wav(44)__Original2.flac(44)__mono_400-42.5161-32.5905-21.2363.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(86) Audiofire 4 output 3_4 to input 3_4.wav(44)__Original2.flac(44)__mono_400-42.5161-32.5905-21.2363.png" width="60" /></a><br /> <em>david1103: 0.5 dB (L), 0.4 dB Corr Depth: 25,6 dB (L), 27,4 dB (R) Difference: -45.9 dBFS (L), -47.5 dBFS (R)</em><br /> <br /> <strong>Antelope Audio Eclipse 384 [Eclipse384]</strong><br /> (87) Eclipse DA-AD Loop.wav(44)__Original2.flac(44)__mono_400-43.1993<strong>-33.1098</strong>-21.2989.png <a href="http://soundexpert.org/documents/10179/1964064/(87) Eclipse DA-AD Loop.wav(44)__Original2.flac(44)__mono_400-43.1993-33.1098-21.2989.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(87) Eclipse DA-AD Loop.wav(44)__Original2.flac(44)__mono_400-43.1993-33.1098-21.2989.png" width="60" /></a><br /> <em>Giuseppe Zaccaria: -0.1 dB (L), -0.2 dB (R) Corr Depth: 26,3 dB (L), 27,8 dB (R) Difference: -46.6 dBFS (L) -47.9 dBFS (R)</em><br /> <br /> <strong>Universal Audio Apollo 8 Duo [Apollo8Duo]</strong><br /> (88) Apollo mkii loopback.wav(44)__Original2.flac(44)__mono_400-44.6807<strong>-35.7679</strong>-24.8764.png <a href="http://soundexpert.org/documents/10179/1964064/(88) Apollo mkii loopback.wav(44)__Original2.flac(44)__mono_400-44.6807-35.7679-24.8764.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(88) Apollo mkii loopback.wav(44)__Original2.flac(44)__mono_400-44.6807-35.7679-24.8764.png" width="60" /></a><br /> <em>Philip Marinelis: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 30,2 dB (L), 31,8 dB (R) Difference: -46.3 dBFS (L), -47.4 dBFS (R)</em><br /> <br /> <strong>RME Fireface UFX+ [FirefaceUFX+]</strong><br /> (89) RME UFX+ Original2GS.wav(44)__Original2.flac(44)__mono_400-43.5146<strong>-34.0965</strong>-22.4001.png <a href="http://soundexpert.org/documents/10179/1964064/%2889%29%20RME%20UFX%252B%20Original2GS.wav%2844%29__Original2.flac%2844%29__mono_400-43.5146-34.0965-22.4001.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%2889%29%20RME%20UFX%252B%20Original2GS.wav%2844%29__Original2.flac%2844%29__mono_400-43.5146-34.0965-22.4001.png" width="60" /></a><br /> <em>paulthesparky: 0.2 dB (L), 0.2 dB (R)..Corr Depth: 28,0 dB (L), 29,5 dB (R) Difference: -46.0 dBFS (L), -47.1 dBFS (R)</em><br /> <br /> <strong>Focusrite Red 4Pre [Red4Pre]</strong><br /> (90) FocusriteRed4Pre_out9-10_in7-8.wav(44)__Original2.flac(44)__mono_400-43.5879<strong>-34.0830</strong>-22.7454.png <a href="http://soundexpert.org/documents/10179/1964064/(90) FocusriteRed4Pre_out9-10_in7-8.wav(44)__Original2.flac(44)__mono_400-43.5879-34.0830-22.7454.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(90) FocusriteRed4Pre_out9-10_in7-8.wav(44)__Original2.flac(44)__mono_400-43.5879-34.0830-22.7454.png" width="60" /></a><br /> <em>jacko: 8,6 dB (L), 8.6 dB (R)..Corr Depth: 27,9 dB (L), 29,5 dB (R) Difference: -46.0 dBFS (L), -47.1 dBFS (R)</em><br /> <br /> <strong>Echo 2 USB [Echo2]</strong><br /> (91) echo 2 usb_24.wav(44)__Original2.flac(44)__mono_400-42.9482<strong>-33.2803</strong>-21.8507.png <a href="http://soundexpert.org/documents/10179/1964064/(91) echo 2 usb_24.wav(44)__Original2.flac(44)__mono_400-42.9482-33.2803-21.8507.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(91) echo 2 usb_24.wav(44)__Original2.flac(44)__mono_400-42.9482-33.2803-21.8507.png" width="60" /></a><br /> <em>bezen4UK: 2,3 dB (L), 2,3 dB (R)..Corr Depth: 26,9 dB (L), 28,6 dB (R) Difference: -45.7 dBFS (L), -47.0 dBFS (R)</em><br /> <br /> <strong>Universal Audio Apollo Quad [ApolloQuad]</strong><br /> (92) 4. Apollo Quad clocked interally.wav(44)__Original2.flac(44)__mono_400-38.2636<strong>-32.2699</strong>-21.4867.png <a href="http://soundexpert.org/documents/10179/1964064/(92) 4. Apollo Quad clocked interally.wav(44)__Original2.flac(44)__mono_400-38.2636-32.2699-21.4867.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(92) 4. Apollo Quad clocked interally.wav(44)__Original2.flac(44)__mono_400-38.2636-32.2699-21.4867.png" width="60" /></a><br /> <em>davidbayles: 0.3dB (L), 0.3dB (R). Corr Depth: 26,5 dB (L), 28,0 dB (R). Difference: -45.7 dBFS (L), -46.4 dBFS (R)</em><br /> <br /> <strong>E-MU 1616M [EMU1616M]</strong><br /> (93) Original2Loop0.wav(44)__Original2.flac(44)__mono_400-38.1086<strong>-32.2718</strong>-22.1601.png <a href="http://soundexpert.org/documents/10179/1964064/(93) Original2Loop0.wav(44)__Original2.flac(44)__mono_400-38.1086-32.2718-22.1601.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(93) Original2Loop0.wav(44)__Original2.flac(44)__mono_400-38.1086-32.2718-22.1601.png" width="60" /></a><br /> <em>vechung: 9.7 dB (L), 9.6 dB (R)..Corr Depth: 26,3 dB (L), 28,4 dB (R) Difference: -45.5 dBFS (L), -46.5 dBFS (R)</em><br /> (94) Original2_E-MU_1616m.wav(44)__Original2.flac(44)__mono_400-37.4465<strong>-31.3628</strong>-21.1846.png <a href="http://soundexpert.org/documents/10179/1964064/(94) Original2_E-MU_1616m.wav(44)__Original2.flac(44)__mono_400-37.4465-31.3628-21.1846.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(94) Original2_E-MU_1616m.wav(44)__Original2.flac(44)__mono_400-37.4465-31.3628-21.1846.png" width="60" /></a><br /> <em>The Tenant: 0.1 dB (L), 0.0 dB (R)..Corr Depth: 25,5 dB (L), 27,0 dB (R) Difference: -44.8 dBFS (L), -45.5 dBFS (R)</em><br /> <br /> <strong>E-MU 1212M [EMU1212M]</strong><br /> (95) emu1212m.wav(44)__Original2.flac(44)__mono_400-37.6539<strong>-31.5346</strong>-20.8796.png <a href="http://soundexpert.org/documents/10179/1964064/(95) emu1212m.wav(44)__Original2.flac(44)__mono_400-37.6539-31.5346-20.8796.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(95) emu1212m.wav(44)__Original2.flac(44)__mono_400-37.6539-31.5346-20.8796.png" width="60" /></a><br /> <em>tiberius: 0.9 dB (L), 0.8 dB (R)..Corr Depth: 25,7 dB (L), 27,1 dB (R) Difference: -45.0 dBFS (L), -45.7 dBFS (R)</em><br /> <br /> <strong>Mackie Onyx Blackjack [OnyxBlackjack]</strong><br /> (96) MackieBlackJack.wav(44)__Original2.flac(44)__mono_400-36.1451<strong>-32.0076</strong>-24.9744.png <a href="http://soundexpert.org/documents/10179/1964064/(96) MackieBlackJack.wav(44)__Original2.flac(44)__mono_400-36.1451-32.0076-24.9744.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(96) MackieBlackJack.wav(44)__Original2.flac(44)__mono_400-36.1451-32.0076-24.9744.png" width="60" /></a><br /> <em>kegn51: 2,9 dB (L), 2,9 dB (R) Corr Depth: 30,5 dB (L), 32,3 dB (R) Difference: -45.1 dB (L), -44.5 dB (R)</em><br /> <br /> <strong>M-Audio FireWire 410 [FireWire410]</strong><br /> (97) m_audio_fw410_44k1_24bit_back.wav(44)__Original2.flac(44)__mono_400-41.4567<strong>-31.4265</strong>-19.6551.png <a href="http://soundexpert.org/documents/10179/1964064/(97) m_audio_fw410_44k1_24bit_back.wav(44)__Original2.flac(44)__mono_400-41.4567-31.4265-19.6551.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(97) m_audio_fw410_44k1_24bit_back.wav(44)__Original2.flac(44)__mono_400-41.4567-31.4265-19.6551.png" width="60" /></a><br /> <em>JonasNorberg: 0.2dB (L) 0.2dB (R)..Corr Depth: 24,5 dB (L), 26,2 dB (R) Difference: -44.9 dBFS (L), -46.4 dBFS (R)</em><br /> <br /> <strong>M-Audio Profire 2626 [Profire2626]</strong><br /> (98) Profire2626.wav(44)__Original2.flac(44)__mono_400-41.1631<strong>-31.1995</strong>-19.4855.png <a href="http://soundexpert.org/documents/10179/1964064/(98) Profire2626.wav(44)__Original2.flac(44)__mono_400-41.1631-31.1995-19.4855.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(98) Profire2626.wav(44)__Original2.flac(44)__mono_400-41.1631-31.1995-19.4855.png" width="60" /></a><br /> <em>cylens: -0.5 dB (L), -0.5 dB (R)..Corr Depth: 24,4 dB (L), 25,9 dB (R) Difference: -44.8 dBFS (L), -46.1 dBFS (R)</em><br /> <br /> <strong>Ferrofish A32 [FerrofishA32]</strong><br /> (99) TEST-LOOP_01.wav(44)__Original2.flac(44)__mono_400-37.8085<strong>-31.4418</strong>-20.6038.png <a href="http://soundexpert.org/documents/10179/1964064/(99) TEST-LOOP_01.wav(44)__Original2.flac(44)__mono_400-37.8085-31.4418-20.6038.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(99) TEST-LOOP_01.wav(44)__Original2.flac(44)__mono_400-37.8085-31.4418-20.6038.png" width="60" /></a><br /> <em>mudseason: 05 dB (L), 0.5 dB (R)..Corr Depth: 25,7 dB (L), 27,4 dB (R) Difference: -44.8 dBFS (L), -45.4 dBFS (R)</em><br /> <br /> <strong>PreSonus Quantum 4848 [Quantum4848]</strong><br /> (100) PresonusQuantum4848.wav(44)__Original2.flac(44)__mono_400-44.6321<strong>-35.6912</strong>-23.4285.png <a href="http://soundexpert.org/documents/10179/1964064/(100) PresonusQuantum4848.wav(44)__Original2.flac(44)__mono_400-44.6321-35.6912-23.4285.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(100) PresonusQuantum4848.wav(44)__Original2.flac(44)__mono_400-44.6321-35.6912-23.4285.png" width="60" /></a><br /> <em>Deckdaddy: -0.0 dB (L), -0.1 dB (R)..Corr Depth: 31.2 dB (L), 32.9 dB (R) Difference: -44.6 dBFS (L), -45.7 dBFS</em><br /> <br /> <strong>Audient iD44 [Audient iD44]</strong><br /> (101) ID44.wav(44)__Original2.flac(44)__mono_400-42.6802<strong>-34.3248</strong>-23.9218.png <a href="http://soundexpert.org/documents/10179/1964064/(101) ID44.wav(44)__Original2.flac(44)__mono_400-42.6802-34.3248-23.9218.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(101) ID44.wav(44)__Original2.flac(44)__mono_400-42.6802-34.3248-23.9218.png" width="60" /></a><br /> <em>sm5, 1-2 out to Insert Returns 1-2: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 29,1 dB (L), 30,7 dB (R) Difference: -44.5 dBFS (L), -45.6 dBFS (R)</em><br /> <br /> <strong>Echo Audiofire 8 non adat CS4272 [Audiofire8]</strong><br /> (102) audiofire8#3.wav(44)__Original2.flac(44)__mono_400-35.3559<strong>-30.4774</strong>-21.5799.png <a href="http://soundexpert.org/documents/10179/1964064/(102) audiofire8%233.wav(44)__Original2.flac(44)__mono_400-35.3559-30.4774-21.5799.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(102) audiofire8%233.wav(44)__Original2.flac(44)__mono_400-35.3559-30.4774-21.5799.png" width="60" /></a><br /> <em>guze: 0,8 dB (L), 0,9 dB (R) Corr Depth: 26,4 dB (L), 28,2 dB (R) Difference: -44.0 dBFS (L) -43.9 dBFS (R)</em><br /> <br /> <strong>Universal Audio Apollo Twin MkII [ApolloTwinMkII]</strong><br /> (103) Apollo Twin From Main Outs To Line Ins.wav(44)__Original2.flac(44)__mono_400-37.6191<strong>-31.0531</strong>-20.5201.png <a href="http://soundexpert.org/documents/10179/1964064/(103) Apollo Twin From Main Outs To Line Ins.wav(44)__Original2.flac(44)__mono_400-37.6191-31.0531-20.5201.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(103) Apollo Twin From Main Outs To Line Ins.wav(44)__Original2.flac(44)__mono_400-37.6191-31.0531-20.5201.png" width="60" /></a><br /> <em>EvgenyStudio, Main Outs To Line Ins: 5.9 dB (L), 5.9 dB (R)..Corr Depth: 25,7 dB (L), 27,2 dB (R) Difference: -43.5 dBFS (L), 44.3 dBFS (R)</em><br /> (104) apollo twin mk2 one last time - heaphones out to line in 16 bit.wav(44)__Original2.flac(44)__mono_400-42.4040<strong>-32.0973</strong>-20.5079.png <a href="http://soundexpert.org/documents/10179/1964064/(104) apollo twin mk2 one last time - heaphones out to line in 16 bit.wav(44)__Original2.flac(44)__mono_400-42.4040-32.0973-20.5079.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(104) apollo twin mk2 one last time - heaphones out to line in 16 bit.wav(44)__Original2.flac(44)__mono_400-42.4040-32.0973-20.5079.png" width="60" /></a><br /> <em>EvgenyStudio, Headphones out to Line Ins: 2.9 dB (L), 2.9 dB (R)..Corr Depth: 25,7 dB (L), 27,3 dB (R) Difference: -44.8 dBFS (L), -46.0 dBFS (R)</em><br /> <br /> <strong>RME HDSPe AIO [HDSPeAIO]</strong><br /> (105) RME AIO.wav(44)__Original2.flac(44)__mono_400-39.8987<strong>-29.7811</strong>-18.2588.png <a href="http://soundexpert.org/documents/10179/1964064/(105) RME AIO.wav(44)__Original2.flac(44)__mono_400-39.8987-29.7811-18.2588.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(105) RME AIO.wav(44)__Original2.flac(44)__mono_400-39.8987-29.7811-18.2588.png" width="60" /></a><br /> <em>Touf on Pragmatic Audio: 0.7 dB (L), 0.7 dB (R) Corr Depth: 23,0 dB (L), 24,5 dB (R) Difference: -43,4 dBFS (L) , -44,7 dBFS (R)</em><br /> <br /> <strong>RME Multiface II [MultifaceII]</strong><br /> (106) Test-convertissuers-RME-Multiface2-asymetrique.wav(44)__Original2.flac(44)__mono_400-39.7415<strong>-29.6599</strong>-17.8690.png <a href="http://soundexpert.org/documents/10179/1964064/(106) Test-convertissuers-RME-Multiface2-asymetrique.wav(44)__Original2.flac(44)__mono_400-39.7415-29.6599-17.8690.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(106) Test-convertissuers-RME-Multiface2-asymetrique.wav(44)__Original2.flac(44)__mono_400-39.7415-29.6599-17.8690.png" width="60" /></a><br /> <em>juki, Audiofanzine, Unbalanced, -10 dBV: 0.5 dB (L), 0.4 dB (R) Corr Depth: 22,7 dB (L), 24,4 dB (R) Difference: -43.2 dBFS (L) -44.6 dBFS (R)</em><br /> (107) Test-convertissuers-RME-Multiface2-symetrique.wav(44)__Original2.flac(44)__mono_400-39.2435<strong>-29.1632</strong>-17.4221.png <a href="http://soundexpert.org/documents/10179/1964064/(107) Test-convertissuers-RME-Multiface2-symetrique.wav(44)__Original2.flac(44)__mono_400-39.2435-29.1632-17.4221.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(107) Test-convertissuers-RME-Multiface2-symetrique.wav(44)__Original2.flac(44)__mono_400-39.2435-29.1632-17.4221.png" width="60" /></a><br /> <em>juki, Audiofanzine, Balanced, 4 dBu: 0.3 dB (L), 0.2 dB (R) Corr Depth: 22,3 dB (L), 23,9 dB (R) Difference: -42.7 dBFS (L) -44.1 dBFS (R)</em><br /> <br /> <strong>E-MU 0404 USB [EMU0404]</strong><br /> (108) e-mu_0404_usb_LoopBack.wav(44)__Original2.flac(44)__mono_400-39.3723<strong>-29.3333</strong>-17.7661.png <a href="http://soundexpert.org/documents/10179/1964064/(108) e-mu_0404_usb_LoopBack.wav(44)__Original2.flac(44)__mono_400-39.3723-29.3333-17.7661.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(108) e-mu_0404_usb_LoopBack.wav(44)__Original2.flac(44)__mono_400-39.3723-29.3333-17.7661.png" width="60" /></a><br /> <em>EdwardZ7: 0.0 dB (L), -0.0 dB (R)..Corr Depth: 22,4 dB (L), 24,1 dB (R) Difference: -42.9 dBFS (L), -44.3 dBFS (R)</em><br /> <br /> <strong>RME Fireface 800 [Fireface800]</strong><br /> (109) FF800 INTERNAL CLOCK_01.wav(44)__Original2.flac(44)__mono_400-39.2631<strong>-29.1808</strong>-17.4896.png <a href="http://soundexpert.org/documents/10179/1964064/(109) FF800 INTERNAL CLOCK_01.wav(44)__Original2.flac(44)__mono_400-39.2631-29.1808-17.4896.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(109) FF800 INTERNAL CLOCK_01.wav(44)__Original2.flac(44)__mono_400-39.2631-29.1808-17.4896.png" width="60" /></a><br /> <em>genelec79: 0.3 dB (L), 0.3 dB (R) Corr Depth: 22,3 dB (L), 23,9 dB (R) Difference: -42.6 dBFS (R), -44.1 dBFS (L)</em><br /> (110) TEST-LOOP_05.wav(44)__Original2.flac(44)__mono_400-39.2712<strong>-29.2102</strong>-17.5235.png <a href="http://soundexpert.org/documents/10179/1964064/(110) TEST-LOOP_05.wav(44)__Original2.flac(44)__mono_400-39.2712-29.2102-17.5235.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(110) TEST-LOOP_05.wav(44)__Original2.flac(44)__mono_400-39.2712-29.2102-17.5235.png" width="60" /></a><br /> <em>mudseason: 0.6 dB (L), 0.5 dB (R)..Corr Depth: 22,4 dB (L), 23,8 dB (R), Difference: -42.8 dBFS (L), -44.0 dBFS (R)</em><br /> <br /> <strong>Audient ID 14 [AudientID14]</strong><br /> (111) ID14.wav(44)__Original2.flac(44)__mono_400-39.1012<strong>-29.0236</strong>-17.4218.png <a href="http://soundexpert.org/documents/10179/1964064/(111) ID14.wav(44)__Original2.flac(44)__mono_400-39.1012-29.0236-17.4218.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(111) ID14.wav(44)__Original2.flac(44)__mono_400-39.1012-29.0236-17.4218.png" width="60" /></a><br /> <em>sm5: 8.8 dB (L), 9.1 dB (R)..Corr Depth: 22,2 dB (L), 23,7 dB (R) Difference: -42.6 dBFS (L), -43.9 dBFS (R)</em><br /> <br /> <strong>Universal Audio Apolllo x16 [Apolllo16]</strong><br /> (112) Apollo X16 loopback.wav(44)__Original2.flac(44)__mono_400-41.0798<strong>-32.0229</strong>-21.5156.png <a href="http://soundexpert.org/documents/10179/1964064/(112) Apollo X16 loopback.wav(44)__Original2.flac(44)__mono_400-41.0798-32.0229-21.5156.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(112) Apollo X16 loopback.wav(44)__Original2.flac(44)__mono_400-41.0798-32.0229-21.5156.png" width="60" /></a><br /> <em>Philip Marinelis: 0.4 dB (L), 0.4 dB (R)..Corr Depth: 26,7 dB (L), 28,3 dB (R) Difference: -42.4 dBFS (L), -43.5 dBFS (R)</em><br /> <br /> <strong>RME Fireface UCX [FirefaceUCX]</strong><br /> johannburkard, unbalanced link through TS cables and back TRS I/Os:<br /> (113) ADDA Loops Edit 1_+4dBu_Take_1.wav(44)__Original2.flac(44)__mono_400-39.1361<strong>-29.3272</strong>-17.9398.png <a href="http://soundexpert.org/documents/10179/1964064/%28113%29%20ADDA%20Loops%20Edit%201_%252B4dBu_Take_1.wav%2844%29__Original2.flac%2844%29__mono_400-39.1361-29.3272-17.9398.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%28113%29%20ADDA%20Loops%20Edit%201_%252B4dBu_Take_1.wav%2844%29__Original2.flac%2844%29__mono_400-39.1361-29.3272-17.9398.png" width="60" /></a><br /> <em>reference level +4 dBu: 3.6 dB (L), 3.7 dB (R)..Corr Depth: 22,8 dB (L), 24,3 dB (R) Difference: -42.4 dBFS (L), -43.4 dBFS</em><br /> (114) ADDA Loops Edit 1_-10dBV_Take_1.wav(44)__Original2.flac(44)__mono_400-40.2326<strong>-30.4504</strong>-19.0667.png <a href="http://soundexpert.org/documents/10179/1964064/(114) ADDA Loops Edit 1_-10dBV_Take_1.wav(44)__Original2.flac(44)__mono_400-40.2326-30.4504-19.0667.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(114) ADDA Loops Edit 1_-10dBV_Take_1.wav(44)__Original2.flac(44)__mono_400-40.2326-30.4504-19.0667.png" width="60" /></a><br /> <em>reference level -10 dBV: 3.7 dB (L), 3,7 dB (R)..Corr Depth: 24,0 dB (L), 25,5 dB (R) Difference: -43.4 dBFS (L), -44.6 dBFS</em><br /> <br /> <strong>MOTU Traveler MK1</strong> with Black Lion Mod<strong> [TravelerMK1]</strong><br /> (115) BlackLionModMOTUTravelerMK1-InternalClock.wav(44)__Original2.flac(44)__mono_400-38.5601<strong>-28.2983</strong>-16.9642.png <a href="http://soundexpert.org/documents/10179/1964064/(115) BlackLionModMOTUTravelerMK1-InternalClock.wav(44)__Original2.flac(44)__mono_400-38.5601-28.2983-16.9642.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(115) BlackLionModMOTUTravelerMK1-InternalClock.wav(44)__Original2.flac(44)__mono_400-38.5601-28.2983-16.9642.png" width="60" /></a><br /> <em>antichef: 2,0 dB (L), 2,0 dB (R)..Corr Depth: 21,4 dB (L), 23,0 dB (R) Difference: -41.8 dBFS (L), -43.2 dBFS (R)</em><br /> <br /> <strong>MOTU<a href="http://www.gearslutz.com/board/gear.php?id=5300" target="_blank"> </a>Ultralite [Ultralite]</strong><br /> (116) Motu_Ultralite_Loopback.wav(44)__Original2.flac(44)__mono_400-38.2000<strong>-27.9446</strong>-16.4276.png <a href="http://soundexpert.org/documents/10179/1964064/(116) Motu_Ultralite_Loopback.wav(44)__Original2.flac(44)__mono_400-38.2000-27.9446-16.4276.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(116) Motu_Ultralite_Loopback.wav(44)__Original2.flac(44)__mono_400-38.2000-27.9446-16.4276.png" width="60" /></a><br /> <em>dheming: 0.6 dB (L), 0.5 dB (R)..Corr Depth: 21,1 dB (L), 22,6 dB (R) Difference: -41.6 dBFS (L), -42.8 dBFS (R)</em><br /> <br /> <strong>Antelope Zen Studio [ZenStudio]</strong><br /> (117) Zen set to 0_01.wav(44)__Original2.flac(44)__mono_400-38.2486<strong>-28.0381</strong>-16.4675.png <a href="http://soundexpert.org/documents/10179/1964064/(117) Zen set to 0_01.wav(44)__Original2.flac(44)__mono_400-38.2486-28.0381-16.4675.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(117) Zen set to 0_01.wav(44)__Original2.flac(44)__mono_400-38.2486-28.0381-16.4675.png" width="60" /></a><br /> <em>Chris Perra, Gain 0: 16.9 dB (L), 16.8 dB (R)..Corr Depth: 21,1 dB (L), 22,7 dB (R) Difference: -41.6 dBFS (L), -42.9 dBFS (R)</em><br /> (118) Zen set to 30_03.wav(44)__Original2.flac(44)__mono_400-38.2167<strong>-28.0024</strong>-16.4437.png <a href="http://soundexpert.org/documents/10179/1964064/(118) Zen set to 30_03.wav(44)__Original2.flac(44)__mono_400-38.2167-28.0024-16.4437.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(118) Zen set to 30_03.wav(44)__Original2.flac(44)__mono_400-38.2167-28.0024-16.4437.png" width="60" /></a><br /> <em>Chris Perra, Gain 15: 2.2 dB (L), 1.2 dB (R)..Corr Depth: 20,1 dB (L), 22,5 dB (R) Difference: -41.5 dBFS (L), -42.9 dBFS (R)</em><br /> <br /> <strong>Focusrite Liquid Saffire 56 [LiquidSaffire56]</strong><br /> (119) LiquidSaffire56_line34.wav(44)__Original2.flac(44)__mono_400-33.6760<strong>-27.8152</strong>-17.5043.png <a href="http://soundexpert.org/documents/10179/1964064/(119) LiquidSaffire56_line34.wav(44)__Original2.flac(44)__mono_400-33.6760-27.8152-17.5043.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(119) LiquidSaffire56_line34.wav(44)__Original2.flac(44)__mono_400-33.6760-27.8152-17.5043.png" width="60" /></a><br /> <em>eugtone: 0.9 dB (L), 1.3 dB (R)..Corr Depth: 21,9 dB (L), 23,1 dB (R) Difference: -41.4 dBFS (L), -41.8 dBFS (R)</em><br /> (120) Focusrite Liquid Saffire 56.wav(44)__Original2.flac(44)__mono_400-31.1361<strong>-24.5617</strong>-13.6724.png <a href="http://soundexpert.org/documents/10179/1964064/(120) Focusrite Liquid Saffire 56.wav(44)__Original2.flac(44)__mono_400-31.1361-24.5617-13.6724.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(120) Focusrite Liquid Saffire 56.wav(44)__Original2.flac(44)__mono_400-31.1361-24.5617-13.6724.png" width="60" /></a><br /> <em>Melodeath, line output to microphone input + pad: 0.2 dB (L), 0.2 dB (R) Corr Depth: 17,9 dB (L), 19,3 dB (R) Difference: -38.1 dBFS (L), -39.1 dBFS (R)</em><br /> <br /> <strong>Steinberg UR824 [UR824]</strong><br /> (121) UR824-kegn51.wav(44)__Original2.flac(44)__mono_400-37.7119<strong>-27.4924</strong>-16.1406.png <a href="http://soundexpert.org/documents/10179/1964064/(121) UR824-kegn51.wav(44)__Original2.flac(44)__mono_400-37.7119-27.4924-16.1406.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(121) UR824-kegn51.wav(44)__Original2.flac(44)__mono_400-37.7119-27.4924-16.1406.png" width="60" /></a><br /> <em>kegn51: -0.4 (L), 0.2 dB (R) Corr Depth: 20,5 dB (L), 22,2 dB (R) Difference: -41.0 dBFS (L), -42.3 dBFS (R)</em><br /> <br /> <strong>Sony Vaio i7@2.2Ghz [SonyVaio]</strong><br /> (122) Vaio i7@2.2GHz.wav(44)__Original2.flac(44)__mono_400-37.5429<strong>-27.3264</strong>-15.5933.png <a href="http://soundexpert.org/documents/10179/1964064/(122) Vaio i7@2.2GHz.wav(44)__Original2.flac(44)__mono_400-37.5429-27.3264-15.5933.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(122) Vaio i7@2.2GHz.wav(44)__Original2.flac(44)__mono_400-37.5429-27.3264-15.5933.png" width="60" /></a><br /> <em>kegn51: 2.2 dB (L), 2.3 dB (R) Corr Depth: 20,4 dB (L), 22,0 dB (R) Difference: -40.9 dBFS (L) , -42.7 dBFS (R)</em><br /> <br /> <strong>SSL Alpha-Link AX [AlphaLinkAX ]</strong><br /> (123) SSL.wav(44)__Original2.flac(44)__mono_400-37.2815<strong>-27.0828</strong>-15.5377.png <a href="http://soundexpert.org/documents/10179/1964064/(123) SSL.wav(44)__Original2.flac(44)__mono_400-37.2815-27.0828-15.5377.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(123) SSL.wav(44)__Original2.flac(44)__mono_400-37.2815-27.0828-15.5377.png" width="60" /></a><br /> <em>eugtone: 0.3 dB (L), 0.4 dB (R)..Corr Depth: 20,2 dB (L), 21,8 dB (R) Difference: -40.6 dBFS (L), -42.0 dBFS (R)</em><br /> <br /> <strong>TASCAM DA-3000 [DA3000]</strong><br /> (124) DA3000_Loopback.wav(44)__Original2.flac(44)__mono_400-39.5118<strong>-29.2489</strong>-17.6889.png <a href="http://soundexpert.org/documents/10179/1964064/(124) DA3000_Loopback.wav(44)__Original2.flac(44)__mono_400-39.5118-29.2489-17.6889.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(124) DA3000_Loopback.wav(44)__Original2.flac(44)__mono_400-39.5118-29.2489-17.6889.png" width="60" /></a><br /> <em>dheming: 0.5 dB (L), 0.4 dB (R)..Corr Depth: 22,5 dB (L), 24,0 dB (R) Difference: -40.5 dBFS (L), -40.8 dBFS (R)</em><br /> <br /> <strong>Apogee Duet2 [Duet2]</strong><br /> (125) duet2.wav(44)__Original2.flac(44)__mono_400-35.7017<strong>-26.6867</strong>-15.2658.png <a href="http://soundexpert.org/documents/10179/1964064/(125) duet2.wav(44)__Original2.flac(44)__mono_400-35.7017-26.6867-15.2658.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(125) duet2.wav(44)__Original2.flac(44)__mono_400-35.7017-26.6867-15.2658.png" width="60" /></a><br /> <em>isma: 1.0 dB (L), 1.0 dB (R) Corr Depth: 19,8 dB (L), 21,4 dB (R) Difference: -40.2 dBFS (L) -41.6 dBFS (R)</em><br /> <br /> <strong>Yamaha Steinberg MR816X [MR816X]</strong><br /> (126) MR816_2.wav(44)__Original2.flac(44)__mono_400-36.4623<strong>-26.3249</strong>-14.8886.png <a href="http://soundexpert.org/documents/10179/1964064/(126) MR816_2.wav(44)__Original2.flac(44)__mono_400-36.4623-26.3249-14.8886.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(126) MR816_2.wav(44)__Original2.flac(44)__mono_400-36.4623-26.3249-14.8886.png" width="60" /></a><br /> <em>didier.brest: 1.1 dB (L), 0.5 dB (R) Corr Depth: 19,1 dB (L), 21,0 dB (R) Difference: -39.9 dB (L), -41.2 dB (R)</em><br /> <br /> <strong>Antelope Audio Orion [Orion]</strong><br /> (127) 1. Orion clocked internally.wav(44)__Original2.flac(44)__mono_400-36.2909<strong>-26.0420</strong>-14.5483.png <a href="http://soundexpert.org/documents/10179/1964064/(127) 1. Orion clocked internally.wav(44)__Original2.flac(44)__mono_400-36.2909-26.0420-14.5483.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(127) 1. Orion clocked internally.wav(44)__Original2.flac(44)__mono_400-36.2909-26.0420-14.5483.png" width="60" /></a><br /> <em>davidbayle: 0.3 dB (L), 0.2 dB (R) Corr Depth: 19,2 dB (L), 20,7 dB (R) Difference: -39.6 dBFS (L), -40.9 dBFS (R)</em><br /> <br /> <strong>MOTU 828es [MOTU828es]</strong><br /> (128) MOTU 828ES 5&6 to 5&6 TRS.wav(44)_warp_LR_400.wav(44)__Original2.flac(44)__mono_400-51.6098<strong>-43.0362</strong>-31.0553.png <a href="http://soundexpert.org/documents/10179/1964064/%28128%29%20MOTU+828ES+5%266+to+5%266+TRS.wav%2844%29_warp_LR_400.wav%2844%29__Original2.flac%2844%29__mono_400-51.6098-43.0362-31.0553.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" src="http://soundexpert.org/documents/10179/1964064/%28128%29%20MOTU+828ES+5%266+to+5%266+TRS.wav%2844%29_warp_LR_400.wav%2844%29__Original2.flac%2844%29__mono_400-51.6098-43.0362-31.0553.png/8da500d5-5822-4205-b9f3-9a1dfc9765f1?t=1590516008000" style="width: 60px; height: 20px;" /></a><br /> <em>sm5, 5-6 TRS out to 5-6 TRS in: 0.2 dB (L), 0.2 dB (R)..Corr Depth: 39,3 dB (L), 34,7 dB (R) Difference: -39.6 dBFS (L), -39.6 dBFS (R)</em><br /> <br /> <strong>Eventide H8000FW [H8000FW]</strong><br /> (129) Eventide8000FW.wav(44)_warp_LR_400.wav(44)__Original2.flac(44)__mono_400-84.2886<strong>-76.4993</strong>-41.9796.png <a href="http://soundexpert.org/documents/10179/1964064/%28129%29%20Eventide8000FW.wav%2844%29_warp_LR_400.wav%2844%29__Original2.flac%2844%29__mono_400-84.2886-76.4993-41.9796.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" src="http://soundexpert.org/documents/10179/1964064/%28129%29%20Eventide8000FW.wav%2844%29_warp_LR_400.wav%2844%29__Original2.flac%2844%29__mono_400-84.2886-76.4993-41.9796.png/2e39efb9-5947-494a-9de2-44015657235b?t=1590516081000" style="width: 60px; height: 20px;" /></a> (not included in 3D similarity spase as its artifact signature substantially [9dB] differs from others; an outlier)<br /> <em>jeamsler: 6.0 dB (L), 6.0 dB (R)..Corr Depth: 46,6 dB (L), 45,0 dB (R) Difference: -39.6 dBFS (L), -39.6 dBFS (R)</em><br /> <br /> <strong>Roland UA-25 [RolandUA25]</strong><br /> (130) UA25.wav(44)__Original2.flac(44)__mono_400-35.7186<strong>-25.6564</strong>-14.8355.png <a href="http://soundexpert.org/documents/10179/1964064/(130) UA25.wav(44)__Original2.flac(44)__mono_400-35.7186-25.6564-14.8355.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(130) UA25.wav(44)__Original2.flac(44)__mono_400-35.7186-25.6564-14.8355.png" width="60" /></a><br /> <em>bezen4uk: 3.9 dB (L), 3.5 dB (R)..Corr Depth: 18,9 dB (L), 20,3 dB (R) Difference: -39.3 dBFS (L), -40.5 dBFS (R)</em><br /> <br /> <strong>Tascam US-144MKII [US144MKII]</strong><br /> (131) Original2viaTASCAMUS144MKii.wav(44)__Original2.flac(44)__mono_400-35.5312<strong>-25.4980</strong>-14.0053.png <a href="http://soundexpert.org/documents/10179/1964064/(131) Original2viaTASCAMUS144MKii.wav(44)__Original2.flac(44)__mono_400-35.5312-25.4980-14.0053.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(131) Original2viaTASCAMUS144MKii.wav(44)__Original2.flac(44)__mono_400-35.5312-25.4980-14.0053.png" width="60" /></a><br /> <em>capn357: 0,2 dB (L), 0,4 dB (R)..Corr Depth: 18,6 dB (L), 20,2 dB (R) Difference: -39.0 dBFS (L), -40.4 dBFS (R)</em><br /> <br /> <strong>RME Fireface UFX [Fireface UFX]</strong><br /> (132) UFX_12_34.wav(44)__Original2.flac(44)__mono_400-34.9001<strong>-25.3985</strong>-13.7973.png <a href="http://soundexpert.org/documents/10179/1964064/(132) UFX_12_34.wav(44)__Original2.flac(44)__mono_400-34.9001-25.3985-13.7973.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(132) UFX_12_34.wav(44)__Original2.flac(44)__mono_400-34.9001-25.3985-13.7973.png" width="60" /></a><br /> <em>didier.brest, XLR outputs 1-2 to TRS inputs 3-4: 0.8 dB (L), 0.7 dB (R) Corr Depth: 18,5 dB (L), 20,1 dB (R) Difference: -39.0 dBFS (L), -40.3 dBFS (R)</em><br /> (133) UFX.wav(44)__Original2.flac(44)__mono_400-34.8829<strong>-25.3561</strong>-13.7677.png <a href="http://soundexpert.org/documents/10179/1964064/(133) UFX.wav(44)__Original2.flac(44)__mono_400-34.8829-25.3561-13.7677.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(133) UFX.wav(44)__Original2.flac(44)__mono_400-34.8829-25.3561-13.7677.png" width="60" /></a><br /> <em>didier.brest, TRS outputs 5-6 to TRS inputs 3-4: 0.7 dB (L), 0.7 dB (R) Corr Depth: 18,4 dB (L), 20,1 dB (R) Difference: -38.8 dBFS (L), -40.3 dBFS (R)</em><br /> (134) UFX_12_910.wav(44)__Original2.flac(44)__mono_400-31.9148<strong>-21.5927</strong>-10.3861.png <a href="http://soundexpert.org/documents/10179/1964064/(134) UFX_12_910.wav(44)__Original2.flac(44)__mono_400-31.9148-21.5927-10.3861.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(134) UFX_12_910.wav(44)__Original2.flac(44)__mono_400-31.9148-21.5927-10.3861.png" width="60" /></a><br /> <em>didier.brest, outputs 1-2 to XLR preamp inputs 9-10: 0.4 dB (L), 0.4 dB (R) Corr Depth: 14,7 dB (L), 16,2 dB (R) Difference: -35.2 dBFS (L) -36.5 dBFS (R)</em><br /> <br /> <strong>Digidesign 003 Rack [Digi003R]</strong><br /> (135) 003R_Loopback.wav(44)__Original2.flac(44)__mono_400-31.9078<strong>-25.1464</strong>-14.1059.png <a href="http://soundexpert.org/documents/10179/1964064/(135) 003R_Loopback.wav(44)__Original2.flac(44)__mono_400-31.9078-25.1464-14.1059.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(135) 003R_Loopback.wav(44)__Original2.flac(44)__mono_400-31.9078-25.1464-14.1059.png" width="60" /></a><br /> <em>dheming: 0.4 dB (L), 0.5 dB (R) Corr Depth: 18,6 dB (L), 20,0 dB (R) Difference: -38.7 dBFS (L), -39.6 dBFS (R)</em><br /> (136) Digi 003.wav(44)__Original2.flac(44)__mono_400-31.9043<strong>-25.1198</strong>-13.9862.png <a href="http://soundexpert.org/documents/10179/1964064/(136) Digi 003.wav(44)__Original2.flac(44)__mono_400-31.9043-25.1198-13.9862.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(136) Digi 003.wav(44)__Original2.flac(44)__mono_400-31.9043-25.1198-13.9862.png" width="60" /></a><br /> <em>Shptq: 0.5 dB (L), 0,5 dB (R) Corr Depth: 18,4 dB (L), 20,2 dB (R) Difference: -38.5 dBFS (L), -39.8 dBFS (R)</em><br /> <br /> <strong>MOTU M2 [MOTU M2]</strong><br /> (137) 2. MOTU M2 out to MOTU M2 in _ Original2 _ 24_44.1.wav(44)__Original2.flac(44)__mono_400-35.1620-<strong>24.9177</strong>-13.7983.png <a href="http://soundexpert.org/documents/10179/1964064/(137) 2. MOTU M2 out to MOTU M2 in _ Original2 _ 24_44.1.wav(44)__Original2.flac(44)__mono_400-35.1620-24.9177-13.7983.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(137) 2. MOTU M2 out to MOTU M2 in _ Original2 _ 24_44.1.wav(44)__Original2.flac(44)__mono_400-35.1620-24.9177-13.7983.png" width="60" /></a><br /> <em>manisandher: 0.4 dB (L), 0.4 dB (R)..Corr Depth: 18,0 dB (L), 19,7 dB (R) Difference: -38.4 dBFS (L), -39.9 dBFS</em><br /> <br /> <strong>Echo AudioFire 2 [AudioFire2]</strong><br /> (138) AudioFire2_Loopback.wav(44)__Original2.flac(44)__mono_400-27.9907<strong>-24.6209</strong>-20.7021.png <a href="http://soundexpert.org/documents/10179/1964064/(138) AudioFire2_Loopback.wav(44)__Original2.flac(44)__mono_400-27.9907-24.6209-20.7021.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(138) AudioFire2_Loopback.wav(44)__Original2.flac(44)__mono_400-27.9907-24.6209-20.7021.png" width="60" /></a><br /> <em>dheming: 0.6 dB (L), 0.2 dB (R) Corr Depth: 20,8 dB (L), 21,9 dB (R) Difference: -37.8 dBFS (L), -37.9 dBFS (R)</em><br /> <br /> <strong>Focusrite Scarlett 6i6 2nd Gen [Scarlett6i6]</strong><br /> (139) Saffire_6i6.wav(44)__Original2.flac(44)__mono_400-30.0794<strong>-21.1648</strong>-10.1485.png <a href="http://soundexpert.org/documents/10179/1964064/(139) Saffire_6i6.wav(44)__Original2.flac(44)__mono_400-30.0794-21.1648-10.1485.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(139) Saffire_6i6.wav(44)__Original2.flac(44)__mono_400-30.0794-21.1648-10.1485.png" width="60" /></a><br /> <em>Susceptor, 1&2 in to 3&4 out: 1.1 dB (L), 1.2 dB (R)..Corr Depth: 14,3 dB (L), 15,8 dB (R) Difference: -34.7 dBFS (L), -36.0 dBFS (R)</em><br /> (140) Saffire 6i6 Out 3+4 to In 3+4.wav(44)__Original2.flac(44)__mono_400-31.2757<strong>-24.2281</strong>-13.0655.png <a href="http://soundexpert.org/documents/10179/1964064/%28140%29%20Saffire%206i6%20Out%203%252B4%20to%20In%203%252B4.wav%2844%29__Original2.flac%2844%29__mono_400-31.2757-24.2281-13.0655.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%28140%29%20Saffire%206i6%20Out%203%252B4%20to%20In%203%252B4.wav%2844%29__Original2.flac%2844%29__mono_400-31.2757-24.2281-13.0655.png" width="60" /></a><br /> <em>Susceptor, 3&4 in to 3&4 out: 1.1 dB (L), 1.2 dB (R)..Corr Depth: 17,5 dB (L), 19,1 dB (R) Difference: -37.7 dBFS (L), -38.9 dBFS (R)</em><br /> <br /> <strong>Behringer XR18 [XR18]</strong><br /> (141) testfile-xr18-result.wav(44)__Original2.flac(44)__mono_400-34.3762<strong>-23.6690</strong>-12.4202.png <a href="http://soundexpert.org/documents/10179/1964064/(141) testfile-xr18-result.wav(44)__Original2.flac(44)__mono_400-34.3762-23.6690-12.4202.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(141) testfile-xr18-result.wav(44)__Original2.flac(44)__mono_400-34.3762-23.6690-12.4202.png" width="60" /></a><br /> <em>livebox: 9.5 dB (L), 9.7 dB (R)..Corr Depth: 16,7 dB (L), 18,3 dB (R) Difference: -37.2 dBFS (L), -38.6 dBFS (R)</em><br /> <br /> <strong>Zoom F4 [ZoomF4]</strong><br /> (142) Zoom F4.wav(44)__Original2.flac(44)__mono_400-33.4223<strong>-23.0609</strong>-11.7456.png <a href="http://soundexpert.org/documents/10179/1964064/(142) Zoom F4.wav(44)__Original2.flac(44)__mono_400-33.4223-23.0609-11.7456.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(142) Zoom F4.wav(44)__Original2.flac(44)__mono_400-33.4223-23.0609-11.7456.png" width="60" /></a><br /> <em>sm5, main out in XLR 1-2: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 16,2 dB (L), 17,7 dB (R), Difference: -36.6 dBFS (L), -38.0 dBFS (R)</em><br /> (143) Zoom 1-2 OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.1415<strong>-22.5916</strong>-11.6678.png <a href="http://soundexpert.org/documents/10179/1964064/(143) Zoom 1-2 OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.1415-22.5916-11.6678.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(143) Zoom 1-2 OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.1415-22.5916-11.6678.png" width="60" /></a><br /> <em>sm5, main out in unbalanced stereo TRS 5-6 input: 5,5 dB (L), 5,6 dB (R)..Corr Depth: 15,7 dB (L), 17,3 dB (R) Difference: -36.1 dBFS (L), -37.5 dBFS (R)</em><br /> (144) Zoom SUB OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.0577<strong>-22.6013</strong>-11.6866.png <a href="http://soundexpert.org/documents/10179/1964064/(144) Zoom SUB OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.0577-22.6013-11.6866.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(144) Zoom SUB OUT to 5-6 IN.wav(44)__Original2.flac(44)__mono_400-33.0577-22.6013-11.6866.png" width="60" /></a><br /> <em>sm5, stereo TRS 3-4 out to 5-6 IN: 0,9 dB (L), 1,0 dB (R)..Corr Depth: 15,7 dB (L), 17,3 dB (R) Difference: -36.1 dBFS (L), -37.5 dBFS (R)</em><br /> <br /> <strong>Aphex IN2 [AphexIN2]</strong><br /> (145) Aphex In2.wav(44)__Original2.flac(44)__mono_400-33.2101<strong>-23.0580</strong>-11.4872.png <a href="http://soundexpert.org/documents/10179/1964064/(145) Aphex In2.wav(44)__Original2.flac(44)__mono_400-33.2101-23.0580-11.4872.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(145) Aphex In2.wav(44)__Original2.flac(44)__mono_400-33.2101-23.0580-11.4872.png" width="60" /></a><br /> <em>ben: -0.3 dB (L), 0.3 dB (R) Difference: -36.6 dBFS (L), -38.0 dBFS (R)</em><br /> <br /> <strong>Lavry Blue [Lavry Blue]</strong><br /> (146) lavry crystal.wav(44)__Original2.flac(44)__mono_400-33.9782<strong>-23.6522</strong>-12.1413.png <a href="http://soundexpert.org/documents/10179/1964064/(146) lavry crystal.wav(44)__Original2.flac(44)__mono_400-33.9782-23.6522-12.1413.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(146) lavry crystal.wav(44)__Original2.flac(44)__mono_400-33.9782-23.6522-12.1413.png" width="60" /></a><br /> <em>Touf on Pragmatic Audio, Modes Crystal and Narrow: 0,2 dB (L), 0,2 dB (R)..Corr Depth: 16,8 dB (L), 18,3 dB (R) Difference -36,5 dBFS (L) , -37,5 dBFS (R)</em><br /> <br /> <strong>Asus 11.6" budget laptop [AsusLaptop]</strong><br /> (147) 11_inch_buget_ASUS_internal_soundcard.wav(44)__Original2.flac(44)__mono_400-32.9221<strong>-22.3486</strong>-11.4196.png <a href="http://soundexpert.org/documents/10179/1964064/(147) 11_inch_buget_ASUS_internal_soundcard.wav(44)__Original2.flac(44)__mono_400-32.9221-22.3486-11.4196.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(147) 11_inch_buget_ASUS_internal_soundcard.wav(44)__Original2.flac(44)__mono_400-32.9221-22.3486-11.4196.png" width="60" /></a><br /> <em>kegn51: 1,3 dB (L), 1,7 dB (R) Corr Depth: 15,5 dB (L), 17,0 dB (R) Difference: -35,2 dBFS (L) , -36,2 dBFS (R)</em><br /> <br /> <strong>Edirol FA-66 [EdirolFA66]</strong><br /> (148) FA-66.wav(44)__Original2.flac(44)__mono_400-30.8635<strong>-21.7293</strong>-10.9470.png <a href="http://soundexpert.org/documents/10179/1964064/(148) FA-66.wav(44)__Original2.flac(44)__mono_400-30.8635-21.7293-10.9470.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(148) FA-66.wav(44)__Original2.flac(44)__mono_400-30.8635-21.7293-10.9470.png" width="60" /></a><br /> <em>didier.brest: 1.0 dB (L), 0.6 dB (R) Corr Depth: 15,6 dB (L), 17,1 dB (R) Difference: -34.5 dBFS (L) -35.5 dBFS (R)</em><br /> <br /> <strong>MOTU MicroBook [MicroBook]</strong><br /> (149) MOTU-Microbook.wav(44)__Original2.flac(44)__mono_400-31.0210<strong>-21.1658</strong>-11.4884.png <a href="http://soundexpert.org/documents/10179/1964064/(149) MOTU-Microbook.wav(44)__Original2.flac(44)__mono_400-31.0210-21.1658-11.4884.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(149) MOTU-Microbook.wav(44)__Original2.flac(44)__mono_400-31.0210-21.1658-11.4884.png" width="60" /></a><br /> <em>feutche: 3.7 dB (L), 3.7 dB (R)..Corr Depth: 14,6 dB (L), 16,2 dB (R) Difference: -34.2 dBFS (L), -35.5 dBFS (R)</em><br /> <br /> <strong>Sound Devices MixPre-10T [MixPre10T]</strong><br /> (150) Sound Devices Mixpre-10T x1x2 out aux in.wav(44)__Original2.flac(44)__mono_400-26.5842<strong>-20.2533</strong>-10.6268.png <a href="http://soundexpert.org/documents/10179/1964064/(150) Sound Devices Mixpre-10T x1x2 out aux in.wav(44)__Original2.flac(44)__mono_400-26.5842-20.2533-10.6268.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(150) Sound Devices Mixpre-10T x1x2 out aux in.wav(44)__Original2.flac(44)__mono_400-26.5842-20.2533-10.6268.png" width="60" /></a><br /> <em>sm5, x1/x2 1/8" out into 1/8" Aux in: 0.7 dB (L), 0.6 dB (R)..Corr Depth: 14,2 dB (L), 15,5 dB (R) Difference: -33.5 dBFS (L), -33.5 dBFS (R)</em><br /> (151) MIXPRE LR to 12 xlr.wav(44)__Original2.flac(44)__mono_400-26.0211<strong>-15.4330</strong>-6.3038.png <a href="http://soundexpert.org/documents/10179/1964064/(151) MIXPRE LR to 12 xlr.wav(44)__Original2.flac(44)__mono_400-26.0211-15.4330-6.3038.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(151) MIXPRE LR to 12 xlr.wav(44)__Original2.flac(44)__mono_400-26.0211-15.4330-6.3038.png" width="60" /></a><br /> <em>sm5, L/R Mini XLR to 1/2 XLR: 0.2 dB (L), 0.5 dB (R)..Corr Depth: 8,7 dB (L), 10,3 dB (R) Difference: -29.1 dBFS (L), -30.4 dBFS (R)</em><br /> <br /> <strong>Focusrite Scarlett 2i2 [Scarlett2i2]</strong><br /> (152) Scarlet 2i2.wav(44)__Original2.flac(44)__mono_400-20.6678<strong>-18.2227</strong>-16.0506.png <a href="http://soundexpert.org/documents/10179/1964064/(152) Scarlet 2i2.wav(44)__Original2.flac(44)__mono_400-20.6678-18.2227-16.0506.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(152) Scarlet 2i2.wav(44)__Original2.flac(44)__mono_400-20.6678-18.2227-16.0506.png" width="60" /></a><br /> <em>EvgenyStudio: 15,5 dB (L), 15,5 dB (R)Corr Depth: 19,3 dB (L), 23,6 dB (R) Difference: -32,4 dBFS (L), -31,7 dBFS (R)</em><br /> <br /> <strong>Line 6 POD Studio UX2 [StudioUX2]</strong><br /> (153) Line 6 UX2.wav(44)__Original2.flac(44)__mono_400-28.8268<strong>-17.8301</strong>-9.0815.png <a href="http://soundexpert.org/documents/10179/1964064/(153) Line 6 UX2.wav(44)__Original2.flac(44)__mono_400-28.8268-17.8301-9.0815.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(153) Line 6 UX2.wav(44)__Original2.flac(44)__mono_400-28.8268-17.8301-9.0815.png" width="60" /></a><br /> <em>Piux: -0,5 dB (L), -0,4 dB (R) Corr Depth: 11,0 dB (L), 12,5 dB (R) Difference: -30.6 dBFS (L) -31.6 dBFS (R)</em><br /> <br /> <strong>RME Babyface [Babyface]</strong><br /> (154) Babyface_3.wav(44)__Original2.flac(44)__mono_400-26.8970<strong>-16.0375</strong>-7.3804.png <a href="http://soundexpert.org/documents/10179/1964064/(154) Babyface_3.wav(44)__Original2.flac(44)__mono_400-26.8970-16.0375-7.3804.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(154) Babyface_3.wav(44)__Original2.flac(44)__mono_400-26.8970-16.0375-7.3804.png" width="60" /></a><br /> <em>didier.brest: 0.4 dB (L), 0.5 dB (R) Corr Depth: 9,2 dB (L), 10,8 dB (R) Difference: -29.6 dBFS (L) -30.9 dBFS (R)</em></p> <p> </p> <h4 style="text-align: center;"> External clocking</h4> <p> <strong>MOTU 828 MkII clocked by Lynx Hilo [MOTU828@Hilo]</strong><br /> (155) Original2motuloopclkdbyhilo.wav(44)__Original2.flac(44)__mono_400-53.2871<strong>-43.1804</strong>-30.9241.png <a href="http://soundexpert.org/documents/10179/1964064/(155) Original2motuloopclkdbyhilo.wav(44)__Original2.flac(44)__mono_400-53.2871-43.1804-30.9241.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(155) Original2motuloopclkdbyhilo.wav(44)__Original2.flac(44)__mono_400-53.2871-43.1804-30.9241.png" width="60" /></a><br /> <em>capn357: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> <br /> <strong>Mytek 8x192 ADDA clocked by another Mytek 8x192 ADDA [Mytek8@~]</strong><br /> (156) diffmaker_1stPass-Mytek-Slaved.wav(44)__Original2.flac(44)__mono_400-52.7915<strong>-42.1764</strong>-29.8917.png <a href="http://soundexpert.org/documents/10179/1964064/(156) diffmaker_1stPass-Mytek-Slaved.wav(44)__Original2.flac(44)__mono_400-52.7915-42.1764-29.8917.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(156) diffmaker_1stPass-Mytek-Slaved.wav(44)__Original2.flac(44)__mono_400-52.7915-42.1764-29.8917.png" width="60" /></a><br /> <em>mudseason: -0.1 dB (L), -0.1 dB (R)..Corr Depth: 35,3 dB (L), 36,9 dB (R) Difference: -55.7 dBFS (L), -57.2 dBFS (R)</em><br /> <br /> <strong>Audient iD22 clocked by RME Digiface [AudientiD22@DigiF]</strong><br /> (157) ID22-To-ID22-Clocked-By-Digiface.wav(44)__Original2.flac(44)__mono_400-48.1497<strong>-38.1157</strong>-26.1429.png <a href="http://soundexpert.org/documents/10179/1964064/(157) ID22-To-ID22-Clocked-By-Digiface.wav(44)__Original2.flac(44)__mono_400-48.1497-38.1157-26.1429.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(157) ID22-To-ID22-Clocked-By-Digiface.wav(44)__Original2.flac(44)__mono_400-48.1497-38.1157-26.1429.png" width="60" /></a><br /> <em>feutche: 0.9 dB (L), 0.9 dB (R)..Corr Depth: 31,3 dB (L), 32,8 dB (R) Difference: -51.7 dBFS (L), -53.0 dBFS (R)</em><br /> <br /> <strong>Behringer ADA8200 clocked by RME Digiset [ADA8200@Digiset]</strong><br /> (158) Behri set to 11_01.wav(44)__Original2.flac(44)__mono_400-40.6285<strong>-33.8700</strong>-21.8921.png <a href="http://soundexpert.org/documents/10179/1964064/(158) Behri set to 11_01.wav(44)__Original2.flac(44)__mono_400-40.6285-33.8700-21.8921.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(158) Behri set to 11_01.wav(44)__Original2.flac(44)__mono_400-40.6285-33.8700-21.8921.png" width="60" /></a><br /> <em>Chris Perra, Gain @ 11 o'clock: 6.0 dB (L), 5.5 dB (R)..Corr Depth: 25,5 dB (L), 29,0 dB (R) Difference: -46.6 dBFS (L), -47.7 dBFS (R)</em><br /> <br /> <strong>Behringer ADA8000 clocked by RME Fireface UFX [ADA8000@<strong>FirefUFX</strong>]</strong><br /> (159) ADA 8000 preamp 0.wav(44)__Original2.flac(44)__mono_400-39.5651<strong>-30.9165</strong>-17.7888.png <a href="http://soundexpert.org/documents/10179/1964064/(159) ADA 8000 preamp 0.wav(44)__Original2.flac(44)__mono_400-39.5651-30.9165-17.7888.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(159) ADA 8000 preamp 0.wav(44)__Original2.flac(44)__mono_400-39.5651-30.9165-17.7888.png" width="60" /></a><br /> <em>Krisprolls on Pragmatic Audio, minimum gain : 13,4 dB (L), 13,4 dB (R)..Corr Depth: 24,4 dB (L), 25,9 dB (R) Diff. -44,0 dBFS (L) , -45,3 dBFS (R)</em><br /> (160) ADA 8000 preamp 4 compense manuelle.wav(44)__Original2.flac(44)__mono_400-38.9658<strong>-30.2611</strong>-17.3891.png <a href="http://soundexpert.org/documents/10179/1964064/(160) ADA 8000 preamp 4 compense manuelle.wav(44)__Original2.flac(44)__mono_400-38.9658-30.2611-17.3891.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(160) ADA 8000 preamp 4 compense manuelle.wav(44)__Original2.flac(44)__mono_400-38.9658-30.2611-17.3891.png" width="60" /></a><br /> <em>Krisprolls on Pragmatic Audio, gain @ 4 : 1,2 dB (L), 1,4 dB (R)..Corr Depth: 23,9 dB (L), 25,5 dB (R) Diff. -42,3 dBFS (L) , -44,5 dBFS (R)</em><br /> <br /> <strong>RME OctaMic XTC clocked by RME Fireface UFX [OctaMicXTC@<strong><strong>FirefUFX</strong></strong>]</strong><br /> (161) 1.wav(44)__Original2.flac(44)__mono_400-39.8741<strong>-29.6958</strong>-18.1079.png <a href="http://soundexpert.org/documents/10179/1964064/(161) 1.wav(44)__Original2.flac(44)__mono_400-39.8741-29.6958-18.1079.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(161) 1.wav(44)__Original2.flac(44)__mono_400-39.8741-29.6958-18.1079.png" width="60" /></a><br /> <em>Loicm on Pragmatic Audio, unbalanced phone output to unbalanced instrument inputs 5-6, 13 dB gain: 1,0 dB (L), 1,0 dB (R)..Corr Depth: 22,8 dB (L), 24,4 dB Difference: -43.3 dBFS (L), -44.6 dBFS (R)</em><br /> (162) 2.wav(44)__Original2.flac(44)__mono_400-36.4548<strong>-26.2752</strong>-14.8043.png <a href="http://soundexpert.org/documents/10179/1964064/(162) 2.wav(44)__Original2.flac(44)__mono_400-36.4548-26.2752-14.8043.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(162) 2.wav(44)__Original2.flac(44)__mono_400-36.4548-26.2752-14.8043.png" width="60" /></a><br /> <em>Loicm on Pragmatic Audio, balanced line inputs 1-2, 10 dB gain: 4,5 dB (L), 4,5 dB (R)..Corr Depth: 19,4 dB (L), 21,0 dB (R) Difference: -39.8 dBFS (L), -41.2 dBFS (R)</em><br /> <br /> <strong>MOTU Traveler MK1 clocked by Lynx Aurora 16 or Black Lion Micro Clock mk1 [Traveler@Aurora]</strong><br /> (163) BlackLionModMOTUTravelerMK1-LynxAurora16Clock.wav(44)__Original2.flac(44)__mono_400-38.5843<strong>-28.3126</strong>-17.0157.png <a href="http://soundexpert.org/documents/10179/1964064/(163) BlackLionModMOTUTravelerMK1-LynxAurora16Clock.wav(44)__Original2.flac(44)__mono_400-38.5843-28.3126-17.0157.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(163) BlackLionModMOTUTravelerMK1-LynxAurora16Clock.wav(44)__Original2.flac(44)__mono_400-38.5843-28.3126-17.0157.png" width="60" /></a><br /> <em>antichef: 2,0 dB (L), 2,0 dB (R)..Corr Depth: 21,4 dB (L), 23,0 dB (R) Difference: -41.1 dBFS (L), -42.1 dBFS (R)</em></p> <p> </p> <h4 style="text-align: center;"> Separate converters, synchronised mode</h4> <p style="text-align: center;"> 'master' indicates which converter delivers the master clock when the information is available</p> <p> <strong>Forssell MDAC-4 ----> Focusrite Blue 245 master [MDAC4>Blue245-m]</strong><br /> funkakuchi on Pragmatic Audio = funka on Gearslutz:<br /> (164) Forssell MDAC4 - Focusrite AD 245 (master)_DCoff.wav(44)__Original2.flac(44)__mono_400-72.9098<strong>-67.7212</strong>-55.5849.png <a href="http://soundexpert.org/documents/10179/1964064/(164) Forssell MDAC4 - Focusrite AD 245 (master)_DCoff.wav(44)__Original2.flac(44)__mono_400-72.9098-67.7212-55.5849.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(164) Forssell MDAC4 - Focusrite AD 245 (master)_DCoff.wav(44)__Original2.flac(44)__mono_400-72.9098-67.7212-55.5849.png" width="60" /></a><br /> <em>Focusrite sensitivity 0 dBFS = 16 dBu: 0.1 dB (L), 0.0 dB (R) Corr Depth: 64.7 dB (L), 65.7 dB (R) Difference: -78.0 dBFS (L) -78.0 dBFS (R)</em><br /> (165) Forssell DAC from AD245(master) bis -20 dbu.wav(44)__Original2.flac(44)__mono_400-74.8529<strong>-69.9476</strong>-54.6983.png <a href="http://soundexpert.org/documents/10179/1964064/(165) Forssell DAC from AD245(master) bis -20 dbu.wav(44)__Original2.flac(44)__mono_400-74.8529-69.9476-54.6983.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(165) Forssell DAC from AD245(master) bis -20 dbu.wav(44)__Original2.flac(44)__mono_400-74.8529-69.9476-54.6983.png" width="60" /></a><br /> <em>Focusrite sensitivity 0 dBFS = 20 dBu, serial number = 10: 4.0 dB (L), 4.0 dB (R) Corr Depth: 66.9 dB (L), 69.8 dB (R) Difference: -81.3 dBFS (L) -81.1 dBFS (R)</em><br /> (166) Forssell MDAC-AD245 sn53 wc master_01.wav(44)__Original2.flac(44)__mono_400-73.4507<strong>-68.2952</strong>-54.4116.png <a href="http://soundexpert.org/documents/10179/1964064/(166) Forssell MDAC-AD245 sn53 wc master_01.wav(44)__Original2.flac(44)__mono_400-73.4507-68.2952-54.4116.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(166) Forssell MDAC-AD245 sn53 wc master_01.wav(44)__Original2.flac(44)__mono_400-73.4507-68.2952-54.4116.png" width="60" /></a><br /> <em>Focusrite sensitivity 0 dBFS = 20 dBu, serial number = 53: 3.9 dB (L) 4.0 dB (R) Corr Depth: 69,4 dB (L), 71,5 dB (R) Difference: -80.2 dB (L), -80.2 dB (R)</em><br /> <br /> <strong>MSB Platinum IV Plus DAC ---> MSB Studio ADC master [PlatinumIV>StudioADC-m]</strong><br /> (167) MSB Platinum IV Plus DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-72.1667<strong>-68.3374</strong>-54.3722.png <a href="http://soundexpert.org/documents/10179/1964064/(167) MSB Platinum IV Plus DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-72.1667-68.3374-54.3722.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(167) MSB Platinum IV Plus DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-72.1667-68.3374-54.3722.png" width="60" /></a><br /> <em>DUJS: 4.9 dB (L), 4.9 dB (R) Corr Depth: 62,8 dB (L), 63,4 dB (R) Difference: -79.8 dBFS (L), -80.8 dBFS (R)</em><br /> <br /> <strong>SPL Madison ---> Focusrite Blue 245 master [Madison>Blue245-m]</strong><br /> (168) madison-AD245.wav(44)__Original2.flac(44)__mono_400-76.1935<strong>-69.1550</strong>-54.1043.png <a href="http://soundexpert.org/documents/10179/1964064/(168) madison-AD245.wav(44)__Original2.flac(44)__mono_400-76.1935-69.1550-54.1043.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(168) madison-AD245.wav(44)__Original2.flac(44)__mono_400-76.1935-69.1550-54.1043.png" width="60" /></a><br /> <em>funka: 4.0 dB (L), 4.1 dB (R)..Corr Depth: 68,5 dB (L), 68,7 dB (R) Difference: -79.2 dBFS (L), -79.2 dBFS (R)</em><br /> <br /> <strong>ReQuest Audio The Beast DAC master ---> MSB Platinum Studio ADC [BeastDAC-m>PlatinumSt]</strong><br /> (169) ReQuest Beast Soul DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-71.0213<strong>-66.9507</strong>-53.5505.png <a href="http://soundexpert.org/documents/10179/1964064/(169) ReQuest Beast Soul DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-71.0213-66.9507-53.5505.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(169) ReQuest Beast Soul DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-71.0213-66.9507-53.5505.png" width="60" /></a><br /> <em>DUJS: 4.5 dB (L), 4.4 dB (R). Corr Depth: 62,0 dB (L), 63,4 dB (R) Difference: -78.5 dBFS (L), -77.7 dBFS (R)</em><br /> <br /> <strong>Swissonic DA24 MkII ---> Texas Instrument PCM4222 Evaluation Module master [DA24MkII>PCM4222EVM-m]</strong><br /> (170) Swiss_EVM_1-2kres.wav(44)__Original2.flac(44)__mono_400-75.5627<strong>-64.6181</strong>-51.1182.png <a href="http://soundexpert.org/documents/10179/1964064/(170) Swiss_EVM_1-2kres.wav(44)__Original2.flac(44)__mono_400-75.5627-64.6181-51.1182.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(170) Swiss_EVM_1-2kres.wav(44)__Original2.flac(44)__mono_400-75.5627-64.6181-51.1182.png" width="60" /></a><br /> <em>living sounds, DC filter off: 0,1 dB (L), 0,1 dB (R) Corr Depth: 82,6 dB (L), 85,5 dB (R) Difference: -73.0 dBFS (L), -73.8 dBFS (R)</em><br /> <br /> <strong>SPL Madison ---> Texas Instrument PCM4222 Evaluation Module master [Madison>PCM4222EVM-m]</strong><br /> (171) Madison_EVM.wav(44)__Original2.flac(44)__mono_400-77.4194<strong>-71.0548</strong>-57.9201.png <a href="http://soundexpert.org/documents/10179/1964064/(171) Madison_EVM.wav(44)__Original2.flac(44)__mono_400-77.4194-71.0548-57.9201.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(171) Madison_EVM.wav(44)__Original2.flac(44)__mono_400-77.4194-71.0548-57.9201.png" width="60" /></a><br /> <em>living sounds, <a href="https://www.gearslutz.com/board/showpost.php?p=10549891-post672.html" target="_blank">details of the clocking</a>, DC filter off: 0.2 dB (L), 0.2 dB (R) Corr Depth: 78,7 dB (L), 81,2 dB (R) Difference: -74.4 dBFS, -72.2 dBFS</em><br /> <br /> <strong>ESI Juli@ XTe DAC ---> MSB Studio ADC master [Juli@XTe>StudioADC-m]</strong><br /> (172) Juli DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-60.3626<strong>-52.8186</strong>-28.7025.png <a href="http://soundexpert.org/documents/10179/1964064/(172) Juli DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-60.3626-52.8186-28.7025.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(172) Juli DAC - MSB Studio ADC orig.wav(44)__Original2.flac(44)__mono_400-60.3626-52.8186-28.7025.png" width="60" /></a><br /> <em>DUJS: 1.6 dB (L), 1.6 dB (R) Corr Depth: 46,0 dB (L), 48,0 dB (R) Difference: -66.1 dBFS (L), -67.6 dBFS (R)</em><br /> <br /> <strong>Zod Audio modded Ross Martin Audio AES8 ---> Metric Halo ULN-8 3d master [RossMartin>Halo-m]</strong><br /> (173) ZOD 8 into ULN3D (master).wav(44)__Original2.flac(44)__mono_400-53.4635<strong>-43.2159</strong>-31.0677.png <a href="http://soundexpert.org/documents/10179/1964064/(173) ZOD 8 into ULN3D (master).wav(44)__Original2.flac(44)__mono_400-53.4635-43.2159-31.0677.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(173) ZOD 8 into ULN3D (master).wav(44)__Original2.flac(44)__mono_400-53.4635-43.2159-31.0677.png" width="60" /></a><br /> <em>Actualsizeaudio: -0,1 dB (L), 0,3 dB (R)..Corr Depth: 36,1 dB (L), 37,9 dB (R) Difference: -56.8 dBFS (L), -58.2 dBFS (R)</em><br /> <br /> <strong>Lynx Hilo with SRC 88.2 master ---> MOTU 828 MkII [Hilo-m>MOTU828]</strong><br /> (174) motou44.1spdiftohilo88.2tomotu.wav(44)__Original2.flac(44)__mono_400-53.2389<strong>-43.2167</strong>-31.0373.png <a href="http://soundexpert.org/documents/10179/1964064/(174) motou44.1spdiftohilo88.2tomotu.wav(44)__Original2.flac(44)__mono_400-53.2389-43.2167-31.0373.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(174) motou44.1spdiftohilo88.2tomotu.wav(44)__Original2.flac(44)__mono_400-53.2389-43.2167-31.0373.png" width="60" /></a><br /> <em>capn357: 0.3 dB (L), 0.4 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.8 dBFS (L), -58.2 dBFS (R)</em><br /> <br /> <strong>MOTU 828 MkII USB ---> MOTU 828 MkII Firewire master [MOTU828U>MOTU828F-m]</strong><br /> (175) original2outmotuusbinmotufwclkedbyfw.wav(44)__Original2.flac(44)__mono_400-53.2943<strong>-43.1813</strong>-30.9408.png <a href="http://soundexpert.org/documents/10179/1964064/(175) original2outmotuusbinmotufwclkedbyfw.wav(44)__Original2.flac(44)__mono_400-53.2943-43.1813-30.9408.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(175) original2outmotuusbinmotufwclkedbyfw.wav(44)__Original2.flac(44)__mono_400-53.2943-43.1813-30.9408.png" width="60" /></a><br /> <em>capn357: 0.1 dB (L), 0.1 dB (R)..Corr Depth: 36,3 dB (L), 37,9 dB (R) Difference: -56.7 dBFS (L), -58.1 dBFS (R)</em><br /> <br /> <strong>Forssell MADA-2 2-a ---> Texas Instrument PCM4222 Evaluation Module master [MADA2>PCM4222EVM-m]</strong><br /> (176) Forssell_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-52.8864<strong>-42.9835</strong>-30.9906.png <a href="http://soundexpert.org/documents/10179/1964064/(176) Forssell_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-52.8864-42.9835-30.9906.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(176) Forssell_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-52.8864-42.9835-30.9906.png" width="60" /></a><br /> <em>Mikathechou: 0.7 dB (L), 0.7 dB (R)..Corr Depth: 36,1 dB (L), 37,7 dB (R) Difference: -56.5 dBFS (L), -57.9 dBFS (R)</em><br /> <br /> <strong>Metric Halo LIO-8 ---> Burl B2 Bomber ADC [LIO8>B2Bomber]</strong><br /> (177) LIO-8 without output jumpers to Burl B2 (Master WC) -16db input.wav(44)__Original2.flac(44)__mono_400-51.7664<strong>-42.0818</strong>-29.8056.png <a href="http://soundexpert.org/documents/10179/1964064/(177) LIO-8 without output jumpers to Burl B2 (Master WC) -16db input.wav(44)__Original2.flac(44)__mono_400-51.7664-42.0818-29.8056.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(177) LIO-8 without output jumpers to Burl B2 (Master WC) -16db input.wav(44)__Original2.flac(44)__mono_400-51.7664-42.0818-29.8056.png" width="60" /></a><br /> <em>Antoine Fabi, B2 WC master: -14 dB / -16 dB B2 input: 1,8 dB / 3,8 dB (L), 1,8 / 3,8 dB (R)..Corr Depth: 35,3 dB (L), 36,8 dB (R), Difference: -55.7 dBFS (L), -57.0 dBFS (R)</em><br /> <br /> <strong>Genex GXD8 --> Burl B2 Bomber ADC master through AES [GXD8>B2Bomber-m]</strong><br /> (178) Genex to Burl Master clock Burl#02.wav(44)__Original2.flac(44)__mono_400-51.0402<strong>-41.1955</strong>-27.6018.png <a href="http://soundexpert.org/documents/10179/1964064/(178) Genex to Burl Master clock Burl%2302.wav(44)__Original2.flac(44)__mono_400-51.0402-41.1955-27.6018.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(178) Genex to Burl Master clock Burl%2302.wav(44)__Original2.flac(44)__mono_400-51.0402-41.1955-27.6018.png" width="60" /></a><br /> <em>Antoine Fabi: 2.0 dB (L), 2.0 dB (R)..Corr Depth: 34,3 dB (L), 36,1 dB (R) Difference: -54.8 dBFS (L), -55.6 dBFS (R)</em><br /> <br /> <strong>Swissonic DA24 Mk2 ---> Audient iD22 master [DA24Mk2>iD22-m]</strong><br /> (179) DA24-To-Audient-Master.wav(44)__Original2.flac(44)__mono_400-51.2067<strong>-41.0919</strong>-29.0235.png <a href="http://soundexpert.org/documents/10179/1964064/(179) DA24-To-Audient-Master.wav(44)__Original2.flac(44)__mono_400-51.2067-41.0919-29.0235.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(179) DA24-To-Audient-Master.wav(44)__Original2.flac(44)__mono_400-51.2067-41.0919-29.0235.png" width="60" /></a><br /> <em>fedor.tche: 0.9 dB (L), 1.0 dB (R)..Corr Depth: 34,2 dB (L), 35,8 dB (R) Difference: -54.6 dBFS (L), -56.0 dBFS (R)</em><br /> <br /> <strong>Lynx Aurora 16 ---> Focusrite Blue 245 master [Aurora16>Blue245-m]</strong><br /> (180) Aurora 16 DAC - AD 245 (master).wav(44)__Original2.flac(44)__mono_400-52.1418<strong>-41.1684</strong>-35.9933.png <a href="http://soundexpert.org/documents/10179/1964064/(180) Aurora 16 DAC - AD 245 (master).wav(44)__Original2.flac(44)__mono_400-52.1418-41.1684-35.9933.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(180) Aurora 16 DAC - AD 245 (master).wav(44)__Original2.flac(44)__mono_400-52.1418-41.1684-35.9933.png" width="60" /></a><br /> <em>funkakuchi on Pragamatic Audio: 0,04 dB (L), 0,02 dB (R) Corr Depth: 63,4 dB (L), 62,2 dB (R) Difference: -53.4 dBFS(L) -52.5 dBFS(R)</em><br /> <br /> <strong>Lynx Aurora ---> Texas Instrument PCM4222 Evaluation Module master [Aurora>PCM4222EVM-m]</strong><br /> (181) Aurora_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-42.8949<strong>-38.1157</strong>-30.7925.png <a href="http://soundexpert.org/documents/10179/1964064/(181) Aurora_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-42.8949-38.1157-30.7925.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(181) Aurora_PCM4222_AESfromPCM4222.wav(44)__Original2.flac(44)__mono_400-42.8949-38.1157-30.7925.png" width="60" /></a><br /> <em>Mikathechou: 1.1 dB (L), 1.1 dB (R)..Corr Depth: 36,1 dB (L), 37,5 dB (R) Difference: -51.2 dBFS (L), -50.9 dBFS (R)</em><br /> <br /> <strong>Genex GXD8 --> Dangerous Music CONVERT-AD+ master through AES [GXD8>ConvertAD+m]</strong><br /> (182) Genex to AD+ Master clock AD+#02.wav(44)__Original2.flac(44)__mono_400-47.6913<strong>-37.3294</strong>-24.4323.png <a href="http://soundexpert.org/documents/10179/1964064/%28182%29%20Genex%20to%20AD%252B%20Master%20clock%20AD%252B%252302.wav%2844%29__Original2.flac%2844%29__mono_400-47.6913-37.3294-24.4323.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/%28182%29%20Genex%20to%20AD%252B%20Master%20clock%20AD%252B%252302.wav%2844%29__Original2.flac%2844%29__mono_400-47.6913-37.3294-24.4323.png" width="60" /></a><br /> <em>Antoine Fabi: 0.4 dB (L), 0.4 dB (R)..Corr Depth: 30,4 dB (L), 32,1 dB (R) Difference: -50.8 dBFS (L), -52.1 dBFS (R)</em><br /> <br /> <strong>Lynx Hilo master ---> MOTU 828 MkII USB [Hilo>MOTU828U-m]</strong><br /> (183) original2outhiloinmotuusbckldbyhilo.wav(44)__Original2.flac(44)__mono_400-42.8549<strong>-38.1151</strong>-30.5741.png <a href="http://soundexpert.org/documents/10179/1964064/(183) original2outhiloinmotuusbckldbyhilo.wav(44)__Original2.flac(44)__mono_400-42.8549-38.1151-30.5741.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(183) original2outhiloinmotuusbckldbyhilo.wav(44)__Original2.flac(44)__mono_400-42.8549-38.1151-30.5741.png" width="60" /></a><br /> <em>capn357: 2.3 dB (L), 2.3 dB (R)..Corr Depth: 36,1 dB (L), 37,5 dB (R) Difference: -51.2 dBFS (L), -50.8 dBFS (R)</em><br /> <br /> <strong>Focusrite Scarlett 18i20 (1rst generation) ---> Antelope Zen Tour [Scarlett18i20>ZenTour]</strong><br /> (184) 18i20 zt clk lock.wav(44)__Original2.flac(44)__mono_400-41.2756<strong>-37.2228</strong>-28.6194.png <a href="http://soundexpert.org/documents/10179/1964064/(184) 18i20 zt clk lock.wav(44)__Original2.flac(44)__mono_400-41.2756-37.2228-28.6194.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(184) 18i20 zt clk lock.wav(44)__Original2.flac(44)__mono_400-41.2756-37.2228-28.6194.png" width="60" /></a><br /> <em>esldude: -0.2 dB (L), -0.2 dB (R)..Corr Depth: 34,3 dB (L), 36,2 dB (R) Difference: -50.7 dBFS (L), -50.3 dBFS (R)</em><br /> <br /> <strong>MOTU 828 MkII ---> Lynx Hilo master [MOTU828MkII>Hilo-m]</strong><br /> (185) original2 out motu in hilo trim20 clkd by hilo.wav(44)__Original2.flac(44)__mono_400-44.6030<strong>-38.4546</strong>-28.2076.png <a href="http://soundexpert.org/documents/10179/1964064/(185) original2 out motu in hilo trim20 clkd by hilo.wav(44)__Original2.flac(44)__mono_400-44.6030-38.4546-28.2076.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(185) original2 out motu in hilo trim20 clkd by hilo.wav(44)__Original2.flac(44)__mono_400-44.6030-38.4546-28.2076.png" width="60" /></a><br /> <em>capn357: 1.6 dB (L), 1.6 dB (R)..Corr Depth: 42,4 dB (L), 44,5 dB (R) Difference: -51.2 dBFS (L), -50.2 dBFS (R)</em><br /> <br /> <strong>Emotiva XMC-1 ---> Lynx Hilo master [XMC1>Hilo-m]</strong><br /> (186) xmc-1tohilo18dbtrimclkedbyhilocoaxasio2dbvol.wav(44)__Original2.flac(44)__mono_400-44.3143<strong>-38.3212</strong>-26.7992.png <a href="http://soundexpert.org/documents/10179/1964064/(186) xmc-1tohilo18dbtrimclkedbyhilocoaxasio2dbvol.wav(44)__Original2.flac(44)__mono_400-44.3143-38.3212-26.7992.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(186) xmc-1tohilo18dbtrimclkedbyhilocoaxasio2dbvol.wav(44)__Original2.flac(44)__mono_400-44.3143-38.3212-26.7992.png" width="60" /></a><br /> <em>capn357: 0.2 dB (L), 0.2 dB (R)..Corr Depth: 41,7 dB (L), 43,8 dB (R) Difference: -51.0 dBFS (L), -50.0 dBFS (R) </em><br /> <br /> <strong>Lavry DA924 ---> Lavry AD122-96MkII clocked by Antelope Isochrone Trinity + Antelope Isochrone 10M [DA924>AD12296MkII]</strong><br /> (187) Lavry Gold.wav(44)__Original2.flac(44)__mono_400-46.5530<strong>-36.4199</strong>-24.3888.png <a href="http://soundexpert.org/documents/10179/1964064/(187) Lavry Gold.wav(44)__Original2.flac(44)__mono_400-46.5530-36.4199-24.3888.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(187) Lavry Gold.wav(44)__Original2.flac(44)__mono_400-46.5530-36.4199-24.3888.png" width="60" /></a><br /> <em>Winston Tones: 0,0 dB (L), 0,0 dB (R) Corr Depth: 29,6 dB (L), 31,1 dB (R) Difference: -50.0 dBFS (L), -51.3 dBFS (R)</em><br /> <br /> <strong>Zod Audio modded Ross Martin Audio AES8 ---> Zod Audio modded RMA PCM4222 slave to Metric Halo ULN-8 3d [AES8DAC>PCM4222]</strong><br /> (188) ZOD 8 into ZOD2 (slave to ULN8).wav(44)__Original2.flac(44)__mono_400-46.2058<strong>-36.0724</strong>-24.0743.png <a href="http://soundexpert.org/documents/10179/1964064/(188) ZOD 8 into ZOD2 (slave to ULN8).wav(44)__Original2.flac(44)__mono_400-46.2058-36.0724-24.0743.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(188) ZOD 8 into ZOD2 (slave to ULN8).wav(44)__Original2.flac(44)__mono_400-46.2058-36.0724-24.0743.png" width="60" /></a><br /> <em>Actualsizeaudio: 3.7 dB (L), 4.1 dB (R)..Corr Depth: 29,2 dB (L), 30,8 dB (R) Difference: -49.6 dBFS (L), -51.0 dBFS (R)</em><br /> <br /> <strong>Ross Martin Audio AES8 DAC ---> Ross Martin Audio PCM4222ADC master [AES8DAC>PCM4222ADC-m]</strong><br /> (189) RMA Dac (slave) to PCM4222 (master).wav(44)__Original2.flac(44)__mono_400-46.1354<strong>-36.0583</strong>-24.1626.png <a href="http://soundexpert.org/documents/10179/1964064/(189) RMA Dac (slave) to PCM4222 (master).wav(44)__Original2.flac(44)__mono_400-46.1354-36.0583-24.1626.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(189) RMA Dac (slave) to PCM4222 (master).wav(44)__Original2.flac(44)__mono_400-46.1354-36.0583-24.1626.png" width="60" /></a><br /> <em>Actualsizeaudio: 2.4 dB (L), 2.1 dB (R)..Corr Depth: 29,3 dB (L), 30,7 dB (R) Difference: -49.7 dBFS (L), -50.9 dBFS (R)</em><br /> <br /> <strong>Forssell MDAC-4 ---> Forssell MADC-2 (1st version) master [MDAC4>MADC2-m]</strong><br /> (190) 02-Forssell loop-140217_1935.wav(44)__Original2.flac(44)__mono_400-46.5444<strong>-36.4571</strong>-24.4736.png <a href="http://soundexpert.org/documents/10179/1964064/(190) 02-Forssell loop-140217_1935.wav(44)__Original2.flac(44)__mono_400-46.5444-36.4571-24.4736.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(190) 02-Forssell loop-140217_1935.wav(44)__Original2.flac(44)__mono_400-46.5444-36.4571-24.4736.png" width="60" /></a><br /> <em>funkakuchi on Pragmatic Audio: 0,5dB (L), 0,5 dB (R) Corr Depth: 29,6 dB (L), 31,1 dB (R) Difference: -49,2 dB (L), -50,3 dB (R)</em><br /> <br /> <strong>Forssell MADA-2 ---> Aurora 16-VT master [MADA2>Aurora16-m]</strong><br /> (191) Forssell_Aurora_clockIntAurora.wav(44)__Original2.flac(44)__mono_400-41.4958<strong>-36.3289</strong>-27.6692.png <a href="http://soundexpert.org/documents/10179/1964064/(191) Forssell_Aurora_clockIntAurora.wav(44)__Original2.flac(44)__mono_400-41.4958-36.3289-27.6692.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(191) Forssell_Aurora_clockIntAurora.wav(44)__Original2.flac(44)__mono_400-41.4958-36.3289-27.6692.png" width="60" /></a><br /> <em>Mikathechou: 1.0 dB (L), 1.0 dB (R) Corr Depth: 32,7 dB (L), 34,5 dB (R) Difference: -46.2 dBFS (L), -46.2 dBFS (R), Difference: -49.6 dBFS (L) -49.4 dBFS (R)</em><br /> <br /> <strong>Tascaml UH-7000 ---> Lynx Hilo master [UH7000>Hilo-m]</strong><br /> (192) Tascam UH-7000 DA to Lynx Hilo AD (master) to digital in of Tascam.wav(44)__Original2.flac(44)__mono_400-42.4532<strong>-37.7077</strong>-31.0485.png <a href="http://soundexpert.org/documents/10179/1964064/(192) Tascam UH-7000 DA to Lynx Hilo AD (master) to digital in of Tascam.wav(44)__Original2.flac(44)__mono_400-42.4532-37.7077-31.0485.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(192) Tascam UH-7000 DA to Lynx Hilo AD (master) to digital in of Tascam.wav(44)__Original2.flac(44)__mono_400-42.4532-37.7077-31.0485.png" width="60" /></a><br /> <em>sm5: 1,0 dB (L), 1,0 dB (R)..Corr Depth: 36,7 dB (L), 38,5 dB (R) Difference: -46.2 dBFS (L), -45.9 dBFS (R)</em><br /> <br /> <strong>Audient ID 14 ---> Lynx Hilo [AudientID14>Hilo]</strong><br /> (193) Hilo adat to ID14 to Hilo Analog In (Hilo master).wav(44)__Original2.flac(44)__mono_400-38.3928<strong>-31.8183</strong>-20.5745.png <a href="http://soundexpert.org/documents/10179/1964064/(193) Hilo adat to ID14 to Hilo Analog In (Hilo master).wav(44)__Original2.flac(44)__mono_400-38.3928-31.8183-20.5745.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(193) Hilo adat to ID14 to Hilo Analog In (Hilo master).wav(44)__Original2.flac(44)__mono_400-38.3928-31.8183-20.5745.png" width="60" /></a><br /> <em>sm5: 5.8 dB (L), 5.8 dB (R)..Corr Depth: 25,4 dB (L), 27,1 dB (R) Difference: -45.3 dBFS (L), -46.2 dBFS (R)</em><br /> <br /> <strong>Emotiva XDA-1 ---> Prism Lyra 1 [XDA1>Lyra1]</strong><br /> (194) Original2viaXDA-1lyra1lowinputampexcablebtusbdigoutlyra1#2.wav(44)__Original2.flac(44)__mono_400-38.6611<strong>-32.1607</strong>-20.8727.png <a href="http://soundexpert.org/documents/10179/1964064/(194) Original2viaXDA-1lyra1lowinputampexcablebtusbdigoutlyra1%232.wav(44)__Original2.flac(44)__mono_400-38.6611-32.1607-20.8727.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(194) Original2viaXDA-1lyra1lowinputampexcablebtusbdigoutlyra1%232.wav(44)__Original2.flac(44)__mono_400-38.6611-32.1607-20.8727.png" width="60" /></a><br /> <em>capn357: 0,0 dB (L), 0,0 dB (R)..Corr Depth: 25,8 dB (L), 27,7 dB (R) Difference: -44.7 dBFS (L), -45.5 dBFS (R)</em><br /> <br /> <strong>Lynx Aurora 16-VT --->_Forssell MADA-2 master [Aurora16>MADA2-m]</strong><br /> (195) Aurora_Forssell_WC-Forssell.wav(44)__Original2.flac(44)__mono_400-39.8410<strong>-34.6240</strong>-24.5616.png <a href="http://soundexpert.org/documents/10179/1964064/(195) Aurora_Forssell_WC-Forssell.wav(44)__Original2.flac(44)__mono_400-39.8410-34.6240-24.5616.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(195) Aurora_Forssell_WC-Forssell.wav(44)__Original2.flac(44)__mono_400-39.8410-34.6240-24.5616.png" width="60" /></a><br /> <em>Mikathechou: 1.1 dB (L), 1,1 dB (R) Corr Depth: 29,6 dB (L), 31,1 dB (R) Difference: -44.3 dBFS (L), -44.4 dBFS (R) Difference: -48.0 dBFS (L), -48.3 dBFS (R)</em><br /> <br /> <strong>Tascam DA3000 ---> Mytek Stereo 192 ADC master [DA3000>MytekS-m]</strong><br /> (196) DA3000_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-44.6737<strong>-33.8231</strong>-22.7333.png <a href="http://soundexpert.org/documents/10179/1964064/(196) DA3000_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-44.6737-33.8231-22.7333.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(196) DA3000_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-44.6737-33.8231-22.7333.png" width="60" /></a><br /> <em>dheming: 3,4 dB (L), 3,3 dB (R)..Corr Depth: 27,0 dB (L), 28,3 dB (R) Difference: -39.9 dBFS (L), -39.4 dBFS (R)</em><br /> <br /> <strong>Digidesign Rack ---> Mytek Stereo 192 ADC master [DigiR>MytekS-m]</strong><br /> (197) 003Rack_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-34.3323<strong>-24.5051</strong>-13.1751.png <a href="http://soundexpert.org/documents/10179/1964064/(197) 003Rack_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-34.3323-24.5051-13.1751.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(197) 003Rack_Mytek(Master).wav(44)__Original2.flac(44)__mono_400-34.3323-24.5051-13.1751.png" width="60" /></a><br /> <em>dheming: 0,7 dB (L), 0,7 dB (R)..Corr Depth: 17,7 dB (L), 19,0 dB (R) Difference: -38.1 dBFS (L), -39.1 dBFS (R)</em></p> <p> </p> <h4 style="text-align: center;"> Separate converters, unsynchronized mode</h4> <p style="text-align: center;"> the DA and AD converters run each on its own clock</p> <p> <strong>Lynx Aurora</strong><strong> ---> Texas Instrument PCM4222 Evaluation Module [Aurora>PCM4222EVM]</strong><br /> (198) Aurora88_EVM.wav(44)__Original2.flac(44)__mono_400-69.4516<strong>-54.3958</strong>-39.0164.png <a href="http://soundexpert.org/documents/10179/1964064/(198) Aurora88_EVM.wav(44)__Original2.flac(44)__mono_400-69.4516-54.3958-39.0164.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(198) Aurora88_EVM.wav(44)__Original2.flac(44)__mono_400-69.4516-54.3958-39.0164.png" width="60" /></a><br /> <em>Aurora clock at 88.2 kHz: 0.3 dB (L), 0.3 dB (R). rate adj=1,0352 ppm.Corr Depth: 65,9 dB (L), 69,9 dB (R) Difference: -65.4 dBFS (L), -66.2 dBFS (R)</em><br /> <br /> <strong>Benchmark DAC2 HGC ---> Mytek Stereo 192 ADC [DAC2HGC>MytekS]</strong><br /> (199) DAC2_Mytek192.wav(44)__Original2.flac(44)__mono_400-52.5419<strong>-42.3526</strong>-30.1894.png <a href="http://soundexpert.org/documents/10179/1964064/(199) DAC2_Mytek192.wav(44)__Original2.flac(44)__mono_400-52.5419-42.3526-30.1894.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(199) DAC2_Mytek192.wav(44)__Original2.flac(44)__mono_400-52.5419-42.3526-30.1894.png" width="60" /></a><br /> <em>dheming: 4,1 dB (L), 4,1 dB (R). rate adj=4,4143 ppm.Corr Depth: 36,1 dB (L), 38,1 dB (R) Difference: -56.9 dBFS (L), -58.2 dBFS (R)</em><br /> <br /> <strong>March Audio DAC1 ---> Antelope Audio Zen Tour [DAC1>ZenTour]</strong><br /> (200) March DAC into Zen Tour.wav(44)__Original2.flac(44)__mono_400-50.8865<strong>-41.2332</strong>-29.1514.png <a href="http://soundexpert.org/documents/10179/1964064/(200) March DAC into Zen Tour.wav(44)__Original2.flac(44)__mono_400-50.8865-41.2332-29.1514.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(200) March DAC into Zen Tour.wav(44)__Original2.flac(44)__mono_400-50.8865-41.2332-29.1514.png" width="60" /></a><br /> <em>esldude: 1,0 dB (L), 0,9 dB (R). rate adj=-0,8183 ppm.Corr Depth: 35,0 dB (L), 37,0 dB (R) Difference: -55.6 dBFS (L), -56.9 dBFS (R)</em><br /> <br /> <strong>Forssell MDAC-4 ---> Alesis MASTERLINK ML-9600 [MDAC4>ML9600]</strong><br /> (201) Forssell MDAC-Masterlink- AD245 clock master for aurora-MDAC - masterlink int clock.wav(44)__Original2.flac(44)__mono_400-50.6652<strong>-40.6636</strong>-28.4954.png<br /> <em>funkakuchi on Pragmatic Audio: 1,1 dB (L), 1,2 dB (R). rate adj=7,8413 ppm.Corr Depth: 34,6 dB (L), 36,2 dB (R) Difference: -55.3 dBFS (L), -56.5 dBFS (R)</em><br /> <br /> <strong>Benchmark DAC2 HGC ---> Digidesign Rack [DAC2HGC>DigiR]</strong><br /> (202) DAC2_003R.wav(44)__Original2.flac(44)__mono_400-41.7863<strong>-37.0504</strong>-29.1267.png <a href="http://soundexpert.org/documents/10179/1964064/(202) DAC2_003R.wav(44)__Original2.flac(44)__mono_400-41.7863-37.0504-29.1267.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(202) DAC2_003R.wav(44)__Original2.flac(44)__mono_400-41.7863-37.0504-29.1267.png" width="60" /></a><br /> <em>dheming: 5,5 dB (L), 5,5 dB (R). Rate adjustment unnecessary.Corr Depth: 35,5 dB (L), 37,9 dB (R) Difference: -49.4 dBFS (L), -49.2 dBFS (R)</em><br /> <br /> <strong>Akai Z8 ---> E-MU 1212M [AkaiZ8>EMU1212M]</strong><br /> (203) z8emu.wav(44)__Original2.flac(44)__mono_400-43.8492<strong>-33.7444</strong>-21.8241.png <a href="http://soundexpert.org/documents/10179/1964064/(203) z8emu.wav(44)__Original2.flac(44)__mono_400-43.8492-33.7444-21.8241.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(203) z8emu.wav(44)__Original2.flac(44)__mono_400-43.8492-33.7444-21.8241.png" width="60" /></a><br /> <em>tiberius: 2,7 dB (L), 3,1 dB (R). rate adj=2,7931 ppm.Corr Depth: 27,3 dB (L), 29,7 dB (R) Difference: -47.9 dBFS (L), -49.6 dBFS (R)</em><br /> <br /> <strong>LG V30 ---> MOTU 828 MkII [LGV30>MOTU828MkII]</strong><br /> (204) original2outlgv30inmotu1.wav(44)__Original2.flac(44)__mono_400-52.4136<strong>-43.0724</strong>-24.1891.png <a href="http://soundexpert.org/documents/10179/1964064/(204) original2outlgv30inmotu1.wav(44)__Original2.flac(44)__mono_400-52.4136-43.0724-24.1891.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(204) original2outlgv30inmotu1.wav(44)__Original2.flac(44)__mono_400-52.4136-43.0724-24.1891.png" width="60" /></a><br /> <em>capn357: 2,2 dB (L), 2,2 dB (R). rate adj=-17,3159 ppm.Corr Depth: 30,6 dB (L), 30,5 dB (R) Difference: -48.6 dBFS (L), -47.6 dBFS (R)</em><br /> <br /> <strong>MOTU Ultralite ---> Mytek Stereo 192 ADC [MOTUUltra>MytekS]</strong><br /> (205) Ultralite_Mytek.wav(44)__Original2.flac(44)__mono_400-52.9438<strong>-42.7334</strong>-29.2274.png <a href="http://soundexpert.org/documents/10179/1964064/(205) Ultralite_Mytek.wav(44)__Original2.flac(44)__mono_400-52.9438-42.7334-29.2274.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(205) Ultralite_Mytek.wav(44)__Original2.flac(44)__mono_400-52.9438-42.7334-29.2274.png" width="60" /></a><br /> <em>dheming: 1,5 dB (L), 1,5 dB (R). rate adj=0,0474 ppm.Corr Depth: 36,8 dB (L), 39,1 dB (R) Difference: -46.9 dBFS (L), -46.2 dBFS (R)</em><br /> <br /> <strong>Benchmark DAC2 HGC ---> Marantz PMD661 [DAC2HGC>PMD661]</strong><br /> (207) DAC2_PMD661.wav(44)__Original2.flac(44)__mono_400-39.4743<strong>-29.3257</strong>-16.7121.png <a href="http://soundexpert.org/documents/10179/1964064/(207) DAC2_PMD661.wav(44)__Original2.flac(44)__mono_400-39.4743-29.3257-16.7121.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(207) DAC2_PMD661.wav(44)__Original2.flac(44)__mono_400-39.4743-29.3257-16.7121.png" width="60" /></a><br /> <em>dheming: 4,1 dB (L), 4,5 dB (R). rate adj=14,8525 ppm.Corr Depth: 23,0 dB (L), 25,1 dB (R) Difference: -43.8 dBFS (L), -45.2 dBFS (R)</em><br /> <br /> <strong>TASCAM DA-3000 ---> Mytek Stereo 192 ADC [DA3000>MytekS]</strong><br /> (208) DA3000_Mytek.wav(44)__Original2.flac(44)__mono_400-44.6648<strong>-33.8309</strong>-22.6994.png <a href="http://soundexpert.org/documents/10179/1964064/(208) DA3000_Mytek.wav(44)__Original2.flac(44)__mono_400-44.6648-33.8309-22.6994.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(208) DA3000_Mytek.wav(44)__Original2.flac(44)__mono_400-44.6648-33.8309-22.6994.png" width="60" /></a><br /> <em>dheming: 3,4 dB (L), 3,3 dB (R). rate adj=0,0426 ppm.Corr Depth: 27,7 dB (L), 29,3 dB (R) Difference: -42.8 dBFS (L), -42.7 dBFS (R)</em><br /> <br /> <strong>Benchmark DAC2 HGC ---> TASCAM DA-3000 [DAC2HGC>DA3000]</strong><br /> (209) DAC2_DA3000.wav(44)__Original2.flac(44)__mono_400-40.5847<strong>-30.4116</strong>-18.7511.png <a href="http://soundexpert.org/documents/10179/1964064/(209) DAC2_DA3000.wav(44)__Original2.flac(44)__mono_400-40.5847-30.4116-18.7511.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(209) DAC2_DA3000.wav(44)__Original2.flac(44)__mono_400-40.5847-30.4116-18.7511.png" width="60" /></a><br /> <em>dheming: 3,1 dB (L), 3,0 dB (R). rate adj=0,0750 ppm.Corr Depth: 24,0 dB (L), 25,9 dB (R) Difference: -42.5 dBFS (L), -43.0 dBFS (R)</em><br /> <br /> <strong>Benchmark DAC2 HGC ---> MOTU Ultralite [DAC2HGC>MOTUUltra]</strong><br /> (210) DAC2_Ultralite.wav(44)__Original2.flac(44)__mono_400-38.1681<strong>-27.9152</strong>-16.3729.png <a href="http://soundexpert.org/documents/10179/1964064/(210) DAC2_Ultralite.wav(44)__Original2.flac(44)__mono_400-38.1681-27.9152-16.3729.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=312,height=109');return false;"><img align="absbottom" alt="" height="20" src="http://soundexpert.org/documents/10179/1964064/(210) DAC2_Ultralite.wav(44)__Original2.flac(44)__mono_400-38.1681-27.9152-16.3729.png" width="60" /></a><br /> <em>dheming: 5,1 dB (L), 5,0 dB (R). rate adj=0,0102 ppm.Corr Depth: 21,7 dB (L), 23,6 dB (R) Difference: -42.3 dBFS (L), -43.6 dBFS (R)</em></p> <p> </p> <p> </p>Serge Smirnoff2020-05-18T13:08:00ZHoFi – The Honest AudioSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/hofi-–-the-honest-audio2021-05-30T20:51:43Z2020-02-29T09:29:00Z<p> <img alt="Singularity One portable audio player (concept)" src="http://soundexpert.org/documents/10179/1842467/hofi2000.jpg/3ad3cb86-adfe-4866-9914-bdbd07635953?t=1582968723000" style="width: 1000px; height: 562px;" /></p> <p> This is an audio player concept, which helps to understand the benefits of manufacturing audio devices with “overkill” audio quality:</p> <p> 1. We listen all recorded music “through ears” of creator(s) – musicians, producers, sound engineers. A “warmth and depth” of sound at a listening point can not be any better or different than that, defined in studio by those people. Playback system can not and should not create the characteristics of sound, it has to transfer them untouched; it has to be transparent.</p> <p> 2. The required transparency is much easier to achieve on the engineering level of audio signal, because we are good enough in engineering and much weaker in psychoacoustics. The local thresholds of audibility for various types of distortion/degradation depend heavily on listeners and music/signals used. Hardly any reliable and universally agreed objective audio metric can be created. It is much easier to establish such metric on the engineering level of signal, based on absolute thresholds of audibility. For designers/engineers of audio circuits it doesn’t matter much what particular level of accuracy for music signal needs to be achieved: -50dB, -100dB or -150dB. They can do this already. Yes, such chips/solutions are higher tech products but in mass production they will be cheap anyway.</p> <p> 3. When playback path is transparent the role of sound engineers will skyrocket because of (1). Today they are in shadow, just a technical stuff for most listeners. This is not fair.</p> <p> 4. On top of this transparent path any audio processing can be added. This is a new market of applications for creative listening: vinyl/tube distortions, spatial enhancers, equalizers, dynamic compressors, concert hall simulators, room correctors, etc. In fact, this is the market of cool/pleasant audio degradations/distortions. Some of them today are sold by high-end industry in the form of their overpriced products. Definitely such “nice degradations” can be better accomplished in software than in hardware.</p> <p> 5. The transparency of audio path then can be easily controlled with a single measurable parameter, which will indicate the class of the audio accuracy of measured device. The innovative music-based audio metric - df-metric - helps to define the required levels of accuracy for various listening environments. Such approach is a better and open alternative to MQA.</p> <p> Many semiconductor companies with sufficient experience can design and manufacture the audio chip for such player. They haven't done this until now only because nobody asked them for; they must be “incentivized” by audio consumers. Measurements of current audio devices on the market according to df-metric help to achieve this goal. And the player above can be a part of successful marketing campaign of the new audio products with the novel concept of Honest Audio / Honest Fidelity / Ho-Fi.</p> <p> </p>Serge Smirnoff2020-02-29T09:29:00ZAudio Quality of High-End Portable PlayersSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-high-end-portable-players2021-01-29T19:59:35Z2019-08-25T19:15:00Z<div class="portlet-msg-info"> <br /> This article is a result of collaboration with <em>csglinux</em> - Head-Fi forum member. The cooperation was so successful that we decided to extend it - to perform df-measurements of portable players with much more accurate measurement instrument. For the purpose we assembled DIY recorder based on TI PCM4222EVM. It is capable of recording music signals with ~-80dB precision, which is sufficient for most portable audio devices. The new df-measurements can be seen either on HypetheSonics web site [<a href="https://www.hypethesonics.com/dapti-database/" target="_blank">https://www.hypethesonics.com/dapti-database/</a>] or in the SE Vault [<a href="http://soundexpert.org/vault/dpa.html">http://soundexpert.org/vault/dpa.html</a>].<br /> <br /> This page is preserved for archival purposes.<br /> </div> <p> </p> <p> <img alt="csglinux testing setup" src="http://soundexpert.org/documents/10179/1529787/csglinux-setup.jpg" style="width: 1000px; height: 424px;" /></p> <p style="margin-left: 40px;"> <strong>Testing setup of headfi member <em>csglinux</em></strong>.</p> <p> </p> <p> <strong><span style="font-size:16px;">T</span></strong>hanks to <em>csglinux</em> we have df-measurements of these high quality portable players:</p> <ul> <li> <strong><a href="#appleiphone5">Apple iPhone 5</a></strong><a href="#appleiphone5"> (as Low Anchor)</a></li> <li> <strong><a href="#appleiphonese">Apple iPhone SE</a></strong></li> <li> <a href="#applea1749"><strong>Apple Lightning to 3.5mm Headphone Jack Adapter</strong></a></li> <li> <a href="#astellkernsp2000"><strong>Astell&Kern SP2000</strong></a></li> <li> <a href="#hugo2"><strong>Chord Hugo 2</strong></a></li> <li> <a href="#DX220"><strong>iBasso DX220</strong></a></li> <li> <a href="#fiiom11"><strong>FiiO M11</strong></a></li> <li> <a href="#lgv30"><strong>LG V30 </strong></a>[•Normal •AUX •High Impedance]</li> <li> <a href="#lgv40"><strong>LG V40 </strong></a>[•Normal •AUX •High Impedance]</li> <li> <a href="#QP1R"><strong>Questyle QP1R</strong></a></li> <li> <a href="#shanlingm0"><strong>Shanling M0</strong></a></li> </ul> <p> The list is expanding, it's limited only by the good will of the contributor and reliability of his RME Babyface Pro. The latter has better specs than SE recorder, so these df-measurements can't be just added to the <a href="http://soundexpert.org/portable-players-beta2" target="_blank">portable players</a> page [the research needed]. But we can compare them separately below. The one-page manual "How to read df-slides" is here → <a href="http://soundexpert.org/portable-players-beta2#howtoreaddfslides" target="_blank">http://soundexpert.org/portable-players-beta2#howtoreaddfslides</a></p> <p style="text-align: right;"> <em>Df-slides below are sorted by histogram median. Top df-slides represent portable players with higher playback fidelity.</em></p> <a id="hugo2" name="hugo2"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Chord Hugo 2" src="http://soundexpert.org/documents/10179/1529787/ChordHugo2%40SE.png" style="width: 1000px; height: 500px;" /><br /> <strong>Chord Hugo 2</strong>: This is how excellent audio performance looks like - three groups of test signals and 1-bit signal alone.</p> <a id="shanlingm0" name="shanlingm0"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Shanling M0" src="http://soundexpert.org/documents/10179/1529787/ShanlingM0%40SE.png" style="width: 1000px; height: 500px;" /><br /> <strong>Shanling M0</strong>: Df-measurements of this player were checked several times. No mistake.</p> <a id="lgv30" name="lgv30"></a> <p> <!--All-off measurements--><img alt="Results of LG V30 audio measurements" src="http://soundexpert.org/documents/10179/1529787/LGV30%40SE.png" style="width:1000px; height:500px;" usemap="#lgv30-map" /><map name="lgv30-map"><area coords="55,0,108,13" href="javascript:showSlide('lgv30-aux');" shape="rect" /> <area coords="110,0,163,13" href="javascript:showSlide('lgv30-high');" shape="rect" /></map><!--Special mode measurements--><img alt="Results of LG V30 [in AUX mode] audio measurements" id="lgv30-aux" src="http://soundexpert.org/documents/10179/1529787/LGV30%28aux%29%40SE.png/e471ce17-6004-43aa-a95b-27e6e736159b?t=1567000201000" style="width:1000px; height:500px; display:none;" usemap="#lgv30-aux-map" /><map name="lgv30-aux-map"><area coords="110,0,163,13" href="javascript:showSlide('lgv30-high');" shape="rect" /> <area coords="989,0,999,10" href="javascript:hideSlide('lgv30-aux');" shape="rect" /></map><!--Special mode measurements--><img alt="Results of LG V30 [in High Impedance mode] audio measurements" id="lgv30-high" src="http://soundexpert.org/documents/10179/1529787/LGV30%28high%29%40SE.png/ddcade63-7c79-4f53-b329-67aada10f857?t=1567000229000" style="width:1000px; height:500px; display:none;" usemap="#lgv30-high-map" /><map name="lgv30-high-map"><area coords="55,0,108,13" href="javascript:showSlide('lgv30-aux');" shape="rect" /> <area coords="989,0,999,10" href="javascript:hideSlide('lgv30-high');" shape="rect" /></map></p> <a id="lgv40" name="lgv40"></a> <p> <!--All-off measurements--><img alt="Results of LG V40 audio measurements" src="http://soundexpert.org/documents/10179/1529787/LGV40%40SE.png" style="width:1000px; height:500px;" usemap="#lgv40-map" /><map name="lgv40-map"><area coords="55,0,108,13" href="javascript:showSlide('lgv40-aux');" shape="rect" /> <area coords="110,0,163,13" href="javascript:showSlide('lgv40-high');" shape="rect" /></map><!--Special mode measurements--><img alt="Results of LG V40 [in AUX mode] audio measurements" id="lgv40-aux" src="http://soundexpert.org/documents/10179/1529787/LGV40%28aux%29%40SE.png" style="width:1000px; height:500px; display:none;" usemap="#lgv40-aux-map" /><map name="lgv40-aux-map"><area coords="110,0,163,13" href="javascript:showSlide('lgv40-high');" shape="rect" /> <area coords="989,0,999,10" href="javascript:hideSlide('lgv40-aux');" shape="rect" /></map><!--Special mode measurements--><img alt="Results of LG V40 [in High Impedance mode] audio measurements" id="lgv40-high" src="http://soundexpert.org/documents/10179/1529787/LGV40%28high%29%40SE.png" style="width:1000px; height:500px; display:none;" usemap="#lgv40-high-map" /><map name="lgv40-high-map"><area coords="55,0,108,13" href="javascript:showSlide('lgv40-aux');" shape="rect" /> <area coords="989,0,999,10" href="javascript:hideSlide('lgv40-high');" shape="rect" /></map></p> <a id="QP1R" name="QP1R"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Questyle QP1R" src="http://soundexpert.org/documents/10179/1529787/QuestyleQP1R%40SE.png" style="width: 1000px; height: 500px;" /></p> <a id="DX220" name="DX220"></a> <p> <!--All-off measurements--><img alt="Audio measurements of iBasso DX220" src="http://soundexpert.org/documents/10179/1529787/iBassoDX220%40SE.png" style="width: 1000px; height: 500px;" /></p> <a id="astellkernsp2000" name="astellkernsp2000"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Astell&Kern SP2000" src="http://soundexpert.org/documents/10179/1529787/Astell%26KernSP2000%40SE.png" style="width: 1000px; height: 500px;" /></p> <a id="applea1749" name="applea1749"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Apple Lightning Audio Adapter" src="http://soundexpert.org/documents/10179/1529787/AppleA1749csglinux%40SE.png" style="width: 1000px; height: 500px;" /><br /> <strong>Apple Lightning to 3.5mm Headphone Jack Adapter</strong>: The only small problem is the jitter visible on Sine 12.5kHz diffrogram (vertical greener lines).</p> <a id="appleiphonese" name="appleiphonese"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Apple iPhone SE" src="http://soundexpert.org/documents/10179/1529787/AppleiPhoneSE%40SE.png" style="width: 1000px; height: 500px;" /></p> <a id="appleiphone5" name="appleiphone5"></a> <p> <!--All-off measurements--><img alt="Audio measurements of Apple iPhone 5" src="http://soundexpert.org/documents/10179/1529787/AppleiPhone5%40SE.png" style="width: 1000px; height: 500px;" /></p> <a id="fiiom11" name="fiiom11"></a> <p> <!--All-off measurements--><img alt="Audio measurements of FiiO M11" src="http://soundexpert.org/documents/10179/1529787/FiiOM11%40SE.png/1142cbcf-5704-4c32-8391-04fe8a0b2bc0?t=1571664890000" style="width: 1000px; height: 500px;" /></p> <p> </p> <p> </p> <a id="simspace" name="simspace"></a> <script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three.r81.min.js"></script><script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three_d.js"></script> <h2> Artifact signatures of the tested devices</h2> <p> In df-metric artifact signatures of devices can be computed and compared with each other. So, audio devices can be grouped according to similarity of their artifact signatures. Below is 3D visualization of such groups for the tested players. You can zoom and rotate the image.</p> <script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three.r81.min.js"></script><script type="text/javascript" src="http://soundexpert.org/documents/10179/1479693/three_d.js"></script> <div id="sim-space" style="margin: 0 50px;"> </div> <script type="text/javascript"> function init_plot() { var params = {}; params.width = 900; params.height = 900; params.font = "Verdana, Arial, sans-serif"; params.div_id = "sim-space"; params.background_color = "#FFFFFF"; params.show_axis_titles = false; //params.axis_color = "#999999"; params.same_scale = [true, true, true]; //params.axis_font_color = "#999999"; //params.axis_font_size = 16; //params.x_scale_bounds = [0, 0.5]; //params.y_scale_bounds = [0, 0.5]; //params.z_scale_bounds = [0, 0.5]; params.show_box = false; params.show_snaps = false; params.show_toggles = false; params.show_ticks = true; params.grid_color = "#dddddd"; params.num_ticks = [4,4,4]; params.tick_font_color = "#dddddd"; params.tick_font_size = 16; params.point_type = "custom"; params.custom_point = "/documents/10179/1479693/cust-point-12.png"; params.default_point_height = 40; params.label_font_size = 16; //params.data = []; params.data = [ {"x":2.3200,"y":0.6418,"z":0.0453,"color":"#9E942E","label":"iBasso DX220"}, {"x":0.0044,"y":1.9045,"z":0.5825,"color":"#939A2D","label":"Chord Hugo 2"}, {"x":0.8178,"y":0.0000,"z":1.8220,"color":"#98972D","label":"Questyle QP1R"}, {"x":0.4444,"y":0.4634,"z":0.2250,"color":"#96982D","label":"LG V30"}, {"x":0.4444,"y":0.4634,"z":0.2250,"color":"#96982D","label":"LG V30 [AUX]"}, {"x":0.4444,"y":0.4634,"z":0.2250,"color":"#96982D","label":"LG V30 [High]"}, {"x":0.4517,"y":0.4659,"z":0.2241,"color":"#96982D","label":"LG V40"}, {"x":0.4517,"y":0.4659,"z":0.2241,"color":"#96982D","label":"LG V40 [AUX]"}, {"x":0.4517,"y":0.4659,"z":0.2241,"color":"#96982D","label":"LG V40 [High]"}, {"x":0.0000,"y":1.8035,"z":0.4421,"color":"#939A2D","label":"Shanling M0"}, {"x":0.6296,"y":0.4300,"z":0.0000,"color":"#A68F2F","label":"FiiO M11"}, {"x":1.8260,"y":0.1135,"z":0.1288,"color":"#9E942E","label":"Astell&Kern SP2000"}, {"x":2.8382,"y":1.1744,"z":0.6270,"color":"#A0932E","label":"Apple iPhone 5"}, {"x":2.8382,"y":1.1744,"z":0.6270,"color":"#A0932E","label":"Apple iPhone SE"}, {"x":2.4759,"y":0.7978,"z":0.1201,"color":"#9F942E","label":"Apple A1749"}]; three_d.make_scatter(params); } init_plot(); </script> <p style="margin-left: 40px;"> <strong>The portable players in similarity space</strong>. The closer devices to each other, the more similar their artifact signatures. Colors of devices correspond to Df values of their histogram medians. The distance (mean-corrected MAE) of 2 dB is critical for relation of Df measurements to subjective scores. For players that have close artifact signatures (distance < 2 dB) their perceived sound quality correlates well to df-measurements performed with substantial amount of real-life music material (histogram medians).</p> <p> </p>Serge Smirnoff2019-08-25T19:15:00ZAudio quality of SBC XQ Bluetooth audio codecSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-sbc-xq-bluetooth-audio-codec2020-06-20T11:03:57Z2019-06-29T21:02:00Z<img alt="SBC XQ logo" src="http://soundexpert.org/documents/10179/1452556/logo-sbcxq.png/d09ccbd8-fbc0-4770-9780-281999200c47?t=1561843487000" style="width: 300px; height: 90px; float: right; margin-left: 30px; margin-bottom: 30px;" /> <p> SBC XQ is not just a new Bluetooth (BT) audio codec, it is a lifehack.</p> <p> Standard BT audio codec SBC is incorporated into all BT stereo audio devices as mandatory [<a href="#references">1</a>][<a href="#references">2</a>]. It can work at arbitrary high bitrates but BT documents, however, recommend 328 kbit/s (44.1/16) for <em>high quality</em> mode. This mode provides <em>just acceptable</em> audio quality according to <a href="http://soundexpert.org/encoders-320-kbps" target="_blank">SE ratings</a>. In order to increase quality of audio transmission over BT:</p> <ul> <li> CSR plc, a multinational semiconductor company acquired APT Licensing Ltd. and introduced aptX audio codec, then aptX HD, then Qualcomm bought all these and additionally introduced aptX Low Lattency and aptX Adaptive codecs</li> <li> Sony introduced its proprietary Hi-Rez LDAC</li> <li> Samsung introduced three new BT audio codecs: HD/Scalable/UHQ-BT</li> <li> Huawei introduced HWA LHDC audio codec</li> <li> Apple uses AAC in its products</li> <li> a guy under the nick ValdikSS wrote the patch for Android and another guy - Pali Rohár - for Linux; these patches unlock higher bitrates of SBC encoder.</li> </ul> <p> It turned out that almost all modern BT headphones, speakers, receivers ... support SBC bitrates up to 730 kbit/s just out of the box. And that patch (SBC XQ) helps to encode BT audio on Andriod smartphones at the following bitrates:</p> <ul> <li> BT EDR 2 - 452.0 kbit/s for 44.1/16, 492.0 kbit/s for 48/16</li> <li> BT EDR 3 - 551.2 kbit/s for 44.1/16, 600.0 kbit/s for 48/16</li> </ul> <p> The choice of bitrates looks like a reasonable compromise between audio quality, compatibility with current BT devices and stability of BT connection [<a href="#references">3</a>][<a href="#references">4</a>].</p> <p> The SBC XQ codec (at bitrates for 44.1/16) was added to our live listening tests:</p> <p> <strong>SBC XQ CBR@452.0 (Bluetooth)</strong> - Subband codec for Bluetooth A2DP profile, CBR, 452.0 kbit/s FBR<br /> CODER: SBC Encoder LIB Version 1.5 (Philips)<br /> - usage: sbc_encoder -v -p -r453000 -oout.sbc ref.wav<br /> - SBC XQ default setting for BT EDR2<br /> - 44100 Hz, Dual Channel<br /> - bitpool: 38, bands: 8, blk_len: 16, allocation method: Loudness<br /> DECODER: SBC Decoder LIB Version 1.5 (Philips)</p> <p> <strong>SBC XQ CBR@551.2 (Bluetooth)</strong> - Subband codec for Bluetooth A2DP profile, CBR, 551.2 kbit/s FBR<br /> CODER: SBC Encoder LIB Version 1.5 (Philips)<br /> - usage: sbc_encoder -v -p -r552000 -oout.sbc ref.wav<br /> - SBC XQ default setting for BT EDR3<br /> - 44100 Hz, Dual Channel<br /> - bitpool: 47, bands: 8, blk_len: 16, allocation method: Loudness<br /> DECODER: SBC Decoder LIB Version 1.5 (Philips)</p> <p> Early ratings (inaccurate so far) are available on the page <a href="http://soundexpert.org/encoders-320-kbps" target="_blank">Encoders 320+ kbit/s</a>. For more accurate results, please, participate in SE listening tests - there is a short instruction on that page below the ratings.</p> <p> </p> <h3> Df-measurements of SBC XQ with music signal</h3> <p style="margin-left: 40px;"> <span style="color:#808080;">If the text below seems a bit confusing, please, refer to the previous article - </span><a href="http://soundexpert.org/articles/-/blogs/audio-quality-of-bluetooth-aptx" target="_blank"><span style="color:#808080;">Audio quality of Bluetooth aptX and aptX HD</span></a></p> <p> Once again, assessment of perceived sound quality by means of any objective measurements should be made with great care. In df-metric we have the criterion, which defines whether df-measurements can be used as such or not. It is similarity<em> of sound signatures</em> or <em>artifact signatures</em> of devices under test. If their artifact signatures are close enough, then their df-measurements correlate well to the scores of perceived sound quality.</p> <p> For broader perspective we will compare artifact signatures of SBC XQ@452.0 and SBC XQ@551.2 with SBC@201 (Low Quality), SBC229 (Middle Quality), SBC@328 (High Quality), aptX@352, aptX HD@529, ADPCM IMA@354, AAC@256. As in previous articles we will use Pink Floyd album “The Dark Side of The Moon” as the test signal.</p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td> <strong>Figure 1</strong>. The dendrogram shows how different BT audio codecs relate to each other according to their artifact signatures. The shorter the link between two codecs, the more similar their artifact signatures. The Spearman distance 0.1 is critical for relation of Df measurements to subjective scores.</td> <td> <img alt="Similarity dendrogram of tested BT codecs" src="http://soundexpert.org/documents/10179/1452556/dendrogram-sbc-aptx.png/3fcbe285-f835-4d17-8660-9f028c41f236?t=1561843507000" style="width: 801px; height: 500px;" /></td> </tr> </tbody> </table> <p> </p> <p> We can see that SBC and aptX codecs have similar artifact signatures (distance<0.1), so their df-measurements are indicative of their perceived sound quality.</p> <img alt="" src="http://soundexpert.org/documents/10179/1452556/BT-df-histograms.png/80cfb11d-1366-45e8-8efa-678671d74a0b?t=1561843501000" style="width: 1000px; height: 1200px;" /> <p style="margin-left: 40px;"> <strong>Figure 2</strong>. Histograms of df-sequences for the codecs under test. Medians and 25/75 percentiles are indicated. Median Df is an estimator of average waveform degradation. Shape of histogram relates to character/type of waveform degradation - artifact signature.</p> <p> </p> <p> Looking at Df medians we can safely conclude that <strong>audio quality of SBC XQ is comparable to aptX HD. And for BT EDR3 devices SBC XQ slightly surpasses aptX HD. It will be impossible to tell them apart in a blind listening test</strong>. SBC codec uses primitive psychoacoustic model for encoding and aptX does not use it at all, so their perceived audio quality is determined mostly by bitrate. Different settings of SBC, including SBC XQ, can be compared to aptX and aptX HD <em>aurally</em> with the help of Bluetooth A2DP SBC/aptX online encoder [<a href="#references">5</a>].</p> <p> All current BT stereo devices could use this higher quality encoding. It just suffices to modify BT stack of sending device. Receiving BT devices that support only mandatory SBC codec will benefit most from this trick.</p> <p> At the moment the required patch is included into LineageOS, Resurrection Remix and crDroid forks of Android. The patch for Linux PulseAudio from Pali Rohár besides SBC XQ also adds support for aptX, aptX HD and FastStream codecs [<a href="#references">6</a>]. This extra quality is for free. It's hard to imagine any objection to including this option into all BT stacks and the main Android branch. You can request this feature in your operating system:</p> <ul> <li> Android: <a href="https://issuetracker.google.com/issues/new?component=190923&template=845103" target="_blank">https://issuetracker.google.com/issues/new?component=190923&template=845103</a></li> <li> Linux (PulseAudio): <a href="https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Community/" target="_blank">https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Community/</a></li> <li> macOS and iOS: <a href="https://www.apple.com/feedback/" target="_blank">https://www.apple.com/feedback/</a></li> <li> Windows: <ul> <li> Win10 - Use Feedback app on the Start Menu</li> <li> Toshiba Bluetooth Stack - <a href="https://www.webcom.toshiba.co.jp/us/voice/" target="_blank">https://www.webcom.toshiba.co.jp/us/voice/</a></li> <li> IVT BlueSoleil (1000Moons) - <a href="http://www.bluesoleil.com/life/254.html" target="_blank">http://www.bluesoleil.com/life/254.html</a></li> <li> Broadcom WIDCOMM BT Stack - <a href="https://www.broadcom.com/company/contact-us/feedback-and-comments" target="_blank">https://www.broadcom.com/company/contact-us/feedback-and-comments</a> and <a href="https://community.broadcom.com/ideation/allideas" target="_blank">https://community.broadcom.com/ideation/allideas</a> (requires registration)</li> </ul> </li> </ul> <p> Future versions of SBC XQ will include more bitrate choices. So, manufacturers of BT headphones, speakers and receivers can further improve audio quality of their BT products simply by removing all limits to SBC decoding parameters, thus providing full support for SBC XQ.</p> <p> <a id="references" name="references"></a></p> <h3> References</h3> <p> [1] Bluetooth SIG, Specification of the Bluetooth System, Profiles, Advanced Audio Distribution Profile, v1.3.2, 2019-01-21, <a href="https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=457083" target="_blank">https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=457083</a></p> <p> [2] Christian Hoene, Mansoor Hyder, “Considering Bluetooth’s Subband Codec (SBC) for Wideband Speech and Audio on the Internet”, Technical Report WSI-2009-3, 2009-10, <a href="https://pdfs.semanticscholar.org/1f19/561d03bc88b67728375566c95bbf77e730d5.pdf" target="_blank">https://pdfs.semanticscholar.org/1f19/561d03bc88b67728375566c95bbf77e730d5.pdf</a></p> <p> [3] ValdikSS, “Bluetooth stack modifications to improve audio quality on headphones without AAC, aptX, or LDAC codecs”, 2019-06-18, <a href="https://habr.com/en/post/456476/" target="_blank">https://habr.com/en/post/456476/</a></p> <p> [4] ValdikSS, “Improve Bluetooth audio quality on headphones without aptX or LDAC”, since 2018-08-22, <a href="https://forum.xda-developers.com/android/software-hacking/improve-bluetooth-audio-quality-t3832615" target="_blank">https://forum.xda-developers.com/android/software-hacking/improve-bluetooth-audio-quality-t3832615</a></p> <p> [5] Bluetooth A2DP SBC/aptX online encoder, <a href="https://btcodecs.valdikss.org.ru/sbc-encoder/" target="_blank">https://btcodecs.valdikss.org.ru/sbc-encoder/</a></p> <p> [6] Pali Rohár, New API for Bluetooth A2DP codecs, since 2019-01-12, <a href="https://patchwork.freedesktop.org/series/55117/" target="_blank">https://patchwork.freedesktop.org/series/55117/</a></p> <p> <a id="sep2019" name="sep2019"></a></p> <p> </p> <h3> Update</h3> <hr /> <p> September 2019</p> <p> Another patch for PulseAudio BT stack is available now from JP Guillemin - <a href="https://github.com/JPGuillemin/pulseaudio/tree/SBC-XQ" target="_blank">https://github.com/JPGuillemin/pulseaudio/tree/SBC-XQ</a>. This patch activates SBC XQ mode in Linux systems in the most simple end effective way - it allows to transmit audio using standard SBC codec in the highest possible quality supported by receiving BT device.</p> <p> </p>Serge Smirnoff2019-06-29T21:02:00ZAudio quality of Xiaomi Redmi 6ASerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-xiaomi-redmi-6a2021-04-16T19:55:52Z2019-05-28T10:00:00Z<p> <img alt="Recording of SE test sequences, played back by Xiaomi Redmi 6A smartphone" src="http://soundexpert.org/documents/10179/1412921/se-redmi6a-recording.jpg/a7168bad-8e60-46ed-aeb4-982138551de8?t=1559042147000" style="width: 500px; height: 620px; float: right; margin-left: 30px;" /><strong><span style="font-size:16px;">W</span></strong>hy not to test some modern entry-level smartphone? What audio quality could we expect? Xiaomi Redmi 6A - around $100. Let's see.</p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> <strong>Figure 1</strong>. Recording of SE test sequences, which include both technical signals and various music material (<a href="http://soundexpert.org/test-signals#variety" target="_blank">the test set "Variety"</a>). Processing of these records results in standard df-measurements presented on Fig.2 below.</p> <p style="clear: right;"> </p> <img alt="Df-slide showing location of various test signals (including 2 hours of music) on Df scale according to their levels of degradation" src="http://soundexpert.org/documents/10179/296478/XiaomiRedmi6A%40SE.png/68d39e1a-94c1-4fb2-998f-94dba027bc54?t=1559044198000" style="width: 1000px; height: 500px;" /> <p style="margin-left: 40px;"> <strong>Figure 2</strong>. Df-slide with audio measurements of Redmi 6A. Df-slides of other devices can be compared with each other on the <a href="http://soundexpert.org/portable-players-beta2">Portable players</a> page.</p> <p> </p> <p> Almost all technical signals are reproduced by the smartphone more accurately than by many devices tested to the moment. Not surprising that real music signal also shows low Df level (the Median, -27.1dB). Artifact signature of Redmi 6A is very close to Shanling M2s (Fig.4) and six out of ten tech.signals have better Df levels with Redmi 6A, including the Median. For sure, Redmi 6A sounds as good as dedicated Hi-Rez. M2s, at least with 32 Ohm headphones. It looks like high quality sound is a standard feature now in smartphones.</p> <p> Conclusion:</p> <p> <strong>Audio quality of Xiaomi Redmi 6A is in line with top smartphones. Amaxing.</strong></p> <br /> <p> </p> <p> </p> <h3> Appendix</h3> <hr /> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: right;"> <em>All-off</em></caption> <tbody> <tr> <td style="text-align:center;"> <span style="font-size:8px;">1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">10</span></td> <td style="text-align:center;"> <span style="font-size:8px;">11</span></td> <td style="text-align:center;"> <span style="font-size:8px;">12</span></td> <td style="text-align:center;"> <span style="font-size:8px;">13</span></td> <td style="text-align:center;"> <span style="font-size:8px;">14</span></td> <td style="text-align:center;"> <span style="font-size:8px;">15</span></td> <td style="text-align:center;"> <span style="font-size:8px;">16</span></td> <td style="text-align:center;"> <span style="font-size:8px;">17</span></td> <td style="text-align:center;"> <span style="font-size:8px;">18</span></td> <td style="text-align:center;"> <span style="font-size:8px;">19</span></td> <td style="text-align:center;"> <span style="font-size:8px;">20</span></td> <td style="text-align:center;"> <span style="font-size:8px;">21</span></td> <td style="text-align:center;"> <span style="font-size:8px;">22</span></td> <td style="text-align:center;"> <span style="font-size:8px;">23</span></td> <td style="text-align:center;"> <span style="font-size:8px;">24</span></td> <td style="text-align:center;"> <span style="font-size:8px;">25</span></td> <td style="text-align:center;"> <span style="font-size:8px;">26</span></td> <td style="text-align:center;"> <span style="font-size:8px;">27</span></td> <td style="text-align:center;"> <span style="font-size:8px;">28</span></td> <td style="text-align:center;"> <span style="font-size:8px;">29</span></td> <td style="text-align:center;"> <span style="font-size:8px;">30</span></td> <td style="text-align:center;"> <span style="font-size:8px;">31</span></td> <td style="text-align:center;"> <span style="font-size:8px;">32</span></td> <td style="text-align:center;"> <span style="font-size:8px;">33</span></td> <td style="text-align:center;"> <span style="font-size:8px;">34</span></td> <td style="text-align:center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-01.wav(192)__ref1.wav(44)__mono_400-40.2318-30.4401%2B0.4583.png/5f69c815-6608-4c1f-871c-deebd73458e8?t=1559042802000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109');return false;"><img alt="Redmi 6A - Variety - 1" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-01.wav%28192%29__ref1.wav%2844%29__mono_400-40.2318-30.4401%2B0.4583.png/5f69c815-6608-4c1f-871c-deebd73458e8?t=1559042802000" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-02.wav(192)__ref2.wav(44)__mono_400-41.4956-25.9723-5.0518.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=851,height=109');return false;"><img alt="Redmi 6A - Variety - 2" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-02.wav(192)__ref2.wav(44)__mono_400-41.4956-25.9723-5.0518.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-03.wav(192)__ref3.wav(44)__mono_400-33.5328-25.6237-5.1995.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109');return false;"><img alt="Redmi 6A - Variety - 3" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-03.wav(192)__ref3.wav(44)__mono_400-33.5328-25.6237-5.1995.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-04.wav(192)__ref4.wav(44)__mono_400-41.3300-33.4198-23.7933.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109');return false;"><img alt="Redmi 6A - Variety - 4" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-04.wav(192)__ref4.wav(44)__mono_400-41.3300-33.4198-23.7933.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-05.wav(192)__ref5.wav(44)__mono_400-45.2744-26.8068-5.1429.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=848,height=109');return false;"><img alt="Redmi 6A - Variety - 5" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-05.wav(192)__ref5.wav(44)__mono_400-45.2744-26.8068-5.1429.png" style="width:31px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-06.wav(192)__ref6.wav(44)__mono_400-41.5588-27.3326-19.2818.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109');return false;"><img alt="Redmi 6A - Variety - 6" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-06.wav(192)__ref6.wav(44)__mono_400-41.5588-27.3326-19.2818.png" style="width:26px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-07.wav(192)__ref7.wav(44)__mono_400-43.4109-32.2971-21.7159.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109');return false;"><img alt="Redmi 6A - Variety - 7" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-07.wav(192)__ref7.wav(44)__mono_400-43.4109-32.2971-21.7159.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-08.wav(192)__ref8.wav(44)__mono_400-31.0682-26.1877-16.7339.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109');return false;"><img alt="Redmi 6A - Variety - 8" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-08.wav(192)__ref8.wav(44)__mono_400-31.0682-26.1877-16.7339.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-09.wav(192)__ref9.wav(44)__mono_400-41.5211-24.1584-21.2210.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109');return false;"><img alt="Redmi 6A - Variety - 9" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-09.wav(192)__ref9.wav(44)__mono_400-41.5211-24.1584-21.2210.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-10.wav(192)__ref10.wav(44)__mono_400-33.9001-24.3103-1.7958.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109');return false;"><img alt="Redmi 6A - Variety - 10" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-10.wav(192)__ref10.wav(44)__mono_400-33.9001-24.3103-1.7958.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-11.wav(192)__ref11.wav(44)__mono_400-38.9848-29.8929-2.3996.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109');return false;"><img alt="Redmi 6A - Variety - 11" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-11.wav(192)__ref11.wav(44)__mono_400-38.9848-29.8929-2.3996.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-12.wav(192)__ref12.wav(44)__mono_400-36.3830-25.4769-13.6570.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=586,height=109');return false;"><img alt="Redmi 6A - Variety - 12" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-12.wav(192)__ref12.wav(44)__mono_400-36.3830-25.4769-13.6570.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-13.wav(192)__ref13.wav(44)__mono_400-40.1135-26.4963-14.1657.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=655,height=109');return false;"><img alt="Redmi 6A - Variety - 13" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-13.wav(192)__ref13.wav(44)__mono_400-40.1135-26.4963-14.1657.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-14.wav(192)__ref14.wav(44)__mono_400-41.0232-27.9907-11.3277.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=289,height=109');return false;"><img alt="Redmi 6A - Variety - 14" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-14.wav(192)__ref14.wav(44)__mono_400-41.0232-27.9907-11.3277.png" style="width:25px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-15.wav(192)__ref15.wav(44)__mono_400-43.7045-35.5145-4.1742.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=483,height=109');return false;"><img alt="Redmi 6A - Variety - 15" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-15.wav(192)__ref15.wav(44)__mono_400-43.7045-35.5145-4.1742.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-16.wav(192)__ref16.wav(44)__mono_400-38.4926-27.5369-3.3842.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109');return false;"><img alt="Redmi 6A - Variety - 16" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-16.wav(192)__ref16.wav(44)__mono_400-38.4926-27.5369-3.3842.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-17.wav(192)__ref17.wav(44)__mono_400-42.0690-34.2688-3.9303.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109');return false;"><img alt="Redmi 6A - 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Variety - 19" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-19.wav(192)__ref19.wav(44)__mono_400-43.9462-33.5164-12.2324.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-20.wav(192)__ref20.wav(44)__mono_400-57.0824-38.8620-14.1406.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109');return false;"><img alt="Redmi 6A - Variety - 20" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-20.wav(192)__ref20.wav(44)__mono_400-57.0824-38.8620-14.1406.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-21.wav(192)__ref21.wav(44)__mono_400-38.9987-31.7024-7.1521.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109');return false;"><img alt="Redmi 6A - Variety - 21" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-21.wav(192)__ref21.wav(44)__mono_400-38.9987-31.7024-7.1521.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-22.wav(192)__ref22.wav(44)__mono_400-35.8846-24.1433-15.0404.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109');return false;"><img alt="Redmi 6A - Variety - 22" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-22.wav(192)__ref22.wav(44)__mono_400-35.8846-24.1433-15.0404.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-23.wav(192)__ref23.wav(44)__mono_400-35.1263-26.4889-23.8040.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109');return false;"><img alt="Redmi 6A - Variety - 23" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-23.wav(192)__ref23.wav(44)__mono_400-35.1263-26.4889-23.8040.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-24.wav(192)__ref24.wav(44)__mono_400-31.7330-21.3697-19.2709.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109');return false;"><img alt="Redmi 6A - Variety - 24" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-24.wav(192)__ref24.wav(44)__mono_400-31.7330-21.3697-19.2709.png" style="width:29px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-25.wav(192)__ref25.wav(44)__mono_400-37.2897-28.1967-19.7937.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109');return false;"><img alt="Redmi 6A - Variety - 25" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-25.wav(192)__ref25.wav(44)__mono_400-37.2897-28.1967-19.7937.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-26.wav(192)__ref26.wav(44)__mono_400-45.2666-26.3484-15.3163.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109');return false;"><img alt="Redmi 6A - Variety - 26" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-26.wav(192)__ref26.wav(44)__mono_400-45.2666-26.3484-15.3163.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-27.wav(192)__ref27.wav(44)__mono_400-49.3885-23.6528-1.5680.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109');return false;"><img alt="Redmi 6A - Variety - 27" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-27.wav(192)__ref27.wav(44)__mono_400-49.3885-23.6528-1.5680.png" style="width:30px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-28.wav(192)__ref28.wav(44)__mono_400-49.2582-20.6259-13.4296.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109');return false;"><img alt="Redmi 6A - Variety - 28" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-28.wav(192)__ref28.wav(44)__mono_400-49.2582-20.6259-13.4296.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-29.wav(192)__ref29.wav(44)__mono_400-33.3694-26.5183-20.5378.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109');return false;"><img alt="Redmi 6A - Variety - 29" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-29.wav(192)__ref29.wav(44)__mono_400-33.3694-26.5183-20.5378.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-30.wav(192)__ref30.wav(44)__mono_400-38.9147-26.7283-11.0751.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109');return false;"><img alt="Redmi 6A - Variety - 30" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-30.wav(192)__ref30.wav(44)__mono_400-38.9147-26.7283-11.0751.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-31.wav(192)__ref31.wav(44)__mono_400-37.6049-26.5510-12.9689.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109');return false;"><img alt="Redmi 6A - Variety - 31" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-31.wav(192)__ref31.wav(44)__mono_400-37.6049-26.5510-12.9689.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-32.wav(192)__ref32.wav(44)__mono_400-40.9546-20.8251-11.3268.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109');return false;"><img alt="Redmi 6A - Variety - 32" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-32.wav(192)__ref32.wav(44)__mono_400-40.9546-20.8251-11.3268.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-33.wav(192)__ref33.wav(44)__mono_400-41.8520-34.2904-12.2571.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109');return false;"><img alt="Redmi 6A - Variety - 33" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-33.wav(192)__ref33.wav(44)__mono_400-41.8520-34.2904-12.2571.png" style="width:25px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-34.wav(192)__ref34.wav(44)__mono_400-50.2526-26.7123-20.2412.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109');return false;"><img alt="Redmi 6A - Variety - 34" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-34.wav(192)__ref34.wav(44)__mono_400-50.2526-26.7123-20.2412.png" style="width:30px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1412921/Redmi6A-35.wav(192)__ref35.wav(44)__mono_400-45.1407-28.3842-25.5466.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109');return false;"><img alt="Redmi 6A - Variety - 35" src="http://soundexpert.org/documents/10179/1412921/Redmi6A-35.wav(192)__ref35.wav(44)__mono_400-45.1407-28.3842-25.5466.png" style="width:25px;height:99px;" /></a></td> </tr> <tr> <td style="text-align:center;"> <span style="font-size:8px;">-30.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-33.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-27.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-32.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-29.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-28.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-35.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-27.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-34.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-33.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-38.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-31.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-21.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-28.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-20.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-20.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-34.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-28.4</span></td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> <strong>Figure 3. </strong>Diffrograms of 35 tracks of <a href="http://soundexpert.org/test-signals#variety">the test set “Variety”</a>, played back through Redmi 6A. They show level of waveform degradation of the musical signal divided into 400ms chunks (one pixel each, max. degradation is Red). Median Df values of the tracks are indicated. Click a track to open in full size for quick comparison with similar tracks from another device. More about diffrograms → <a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion">Diffrogram: visualization of signal differences in audio research</a>.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="text-align: left;"> <strong>Figure 4</strong>. Dendrogram showing similarity of artifact signatures of tested players. The shorter the link between two players, the more similar their artifact signatures.</td> <td> <p style="margin-left: 40px;"> <img alt="Dendrogram showing similarity of artifact signatures of tested players" src="http://soundexpert.org/documents/10179/1412921/XX10.png/1e6cd0de-f49b-4735-913e-bab3edc0cb97?t=1559042888000" style="width: 720px; height: 500px;" /></p> </td> </tr> </tbody> </table> <p> </p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> <table align="right"> <caption style="text-align: left; margin-left: 40px;"> <strong>Table 1</strong>. Underlying matrix of Spearman distances between artifact signatures for the dendrogramm. The Spearman distance = 0.1 is critical for relation of Df measurements to subjective scores. For the players that have similar artifact signatures (distance < 0.1) their perceived sound quality correlates well to df-measurements performed with substantial amount of real-life music material (histogram medians).</caption> <tbody> <tr> <td> </td> <td> <code> (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)</code></td> </tr> <tr> <td> <code> (1) Apple iPad mini 2<br /> (2) HTC Desire C<br /> (3) HTC Desire C (ba)<br /> (4) Shanling M2s<br /> (5) Shanling M2s (HighGain)<br /> (6) Shanling M2s (gradual)<br /> (7) Apple A1749 adapter<br /> (8) OnePlus 6<br /> (9) Apple iPod 5th (Video)<br /> (10) Xiaomi Redmi 6A</code></td> <td> <code> 0 <code> </code><code> <code> </code></code>0.0619 0.0972 0.0445 0.0446 0.0334 0.0374 0.0111 0.0578 0.0318<br /> 0.0619 0<code><code><code> <code> </code><code> </code></code> </code></code>0.0655 0.0149 0.0147 0.0174 0.1494 0.1029 0.0017 0.0286<br /> 0.0972 0.0655 0<code> <code> </code><code> </code></code> 0.0651 0.0651 0.0660 0.1710 0.1306 0.0612 0.0712<br /> 0.0445 0.0149 0.0651 0<code> <code> </code><code> </code></code> 0.0002 0.0024 0.1378 0.0887 0.0112 0.0103<br /> 0.0446 0.0147 0.0651 0.0002 0<code> <code> </code><code> </code></code> 0.0025 0.1379 0.0888 0.0110 0.0106<br /> 0.0334 0.0174 0.0660 0.0024 0.0025 0<code> <code> </code><code> </code></code> 0.1229 0.0752 0.0140 0.0081<br /> 0.0374 0.1494 0.1710 0.1378 0.1379 0.1229 0<code> <code> </code><code> </code></code> 0.0095 0.1455 0.1135<br /> 0.0111 0.1029 0.1306 0.0887 0.0888 0.0752 0.0095 0<code> <code> </code><code> </code></code> 0.0988 0.0689<br /> 0.0578 0.0017 0.0612 0.0112 0.0110 0.0140 0.1455 0.0988 0<code> <code> </code><code> </code></code> 0.0235<br /> 0.0318 0.0286 0.0712 0.0103 0.0106 0.0081 0.1135 0.0689 0.0235 0</code></td> </tr> </tbody> </table> <p style="clear:both;"> </p> <p> </p> <p> </p>Serge Smirnoff2019-05-28T10:00:00ZAudio quality of iPod 5th Generation (Video)Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-ipod-5th-generation-video-2021-04-16T19:43:06Z2019-05-17T10:30:00Z<p> <img alt="Recording of SE test sequences, played back by Apple iPod 5th Gen." src="http://soundexpert.org/documents/10179/1403301/iPod5th-se-recording.jpg/941c48cb-5847-4c0d-8cc7-a8601ff58a77?t=1558356404000" style="width: 500px; height: 578px; float: left; margin-right: 30px;" /><strong><span style="font-size:16px;">T</span></strong>his audio player is from 2005. Like almost all portable players by Apple it was remarkable for its audio quality and usability. Many early iPods are still in use and can be easily found on eBay. Such well-known “anchor” players from the past are important points on the global AQ map, SE is trying to build.</p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> <strong>Figure 1</strong>. Recording of SE test sequences, which include both technical signals and various music material (<a href="http://soundexpert.org/test-signals#variety" target="_blank">the test set "Variety"</a>). Processing of these records results in standard df-measurements presented on Fig.2 below.</p> <p style="clear: left;"> </p> <p style="clear: left;"> </p> <img alt="Df-slide showing location of various test signals (including 2 hours of music) on Df scale according to their levels of degradation" src="http://soundexpert.org/documents/10179/296478/AppleiPod5Video%40SE.png/c50f450a-ae80-47da-98c1-8ffbfa5dea98?t=1558544482000" style="width: 1000px; height: 500px;" /> <p style="margin-left: 40px;"> <strong>Figure 2</strong>. Df-slide with audio measurements of the iPod. It can be compared with Df-slides of other devices on the <a href="http://soundexpert.org/portable-players-beta2">Portable players</a> page.</p> <p> </p> <p> Artifact signature of iPod 5th differs substantially from modern audio solutions by Apple. Sine 1kHz is distorted 10dB higher than sine 12.5kHz. Relative position of triangle signals on Df scale indicates that odd harmonics prevail in the distortions. Almost all tech. signals with this iPod show worse Df levels than with modern ordinary spartphones. High output impedance. Definitely this device has noticeable sound character.</p> <p> Conclusion:</p> <p> <strong>Thanks to Wolfson audio chip with relatively high level of <strong>waveform </strong>degradation iPod 5th (Video) has its own distinctive sound signature (slightly harsh mids, transparent highs). Some music types/genres can benefit from this artifact signature, some other will not. As a result there always be lovers and haters of this player. Starting from iPhone 4 and iPod 6th Gen. Apple uses much more transparent/neutral audio chips from Cirrus Logic. High-Ohm headphones are recommended for this iPod 5th.</strong></p> <br /> <p> </p> <h3> Appendix</h3> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: right;"> <em>All-off</em></caption> <tbody> <tr> <td style="text-align:center;"> <span style="font-size:8px;">1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">10</span></td> <td style="text-align:center;"> <span style="font-size:8px;">11</span></td> <td style="text-align:center;"> <span style="font-size:8px;">12</span></td> <td style="text-align:center;"> <span style="font-size:8px;">13</span></td> <td style="text-align:center;"> <span style="font-size:8px;">14</span></td> <td style="text-align:center;"> <span style="font-size:8px;">15</span></td> <td style="text-align:center;"> <span style="font-size:8px;">16</span></td> <td style="text-align:center;"> <span style="font-size:8px;">17</span></td> <td style="text-align:center;"> <span style="font-size:8px;">18</span></td> <td style="text-align:center;"> <span style="font-size:8px;">19</span></td> <td style="text-align:center;"> <span style="font-size:8px;">20</span></td> <td style="text-align:center;"> <span style="font-size:8px;">21</span></td> <td style="text-align:center;"> <span style="font-size:8px;">22</span></td> <td style="text-align:center;"> <span style="font-size:8px;">23</span></td> <td style="text-align:center;"> <span style="font-size:8px;">24</span></td> <td style="text-align:center;"> <span style="font-size:8px;">25</span></td> <td style="text-align:center;"> <span style="font-size:8px;">26</span></td> <td style="text-align:center;"> <span style="font-size:8px;">27</span></td> <td style="text-align:center;"> <span style="font-size:8px;">28</span></td> <td style="text-align:center;"> <span style="font-size:8px;">29</span></td> <td style="text-align:center;"> <span style="font-size:8px;">30</span></td> <td style="text-align:center;"> <span style="font-size:8px;">31</span></td> <td style="text-align:center;"> <span style="font-size:8px;">32</span></td> <td style="text-align:center;"> <span style="font-size:8px;">33</span></td> <td style="text-align:center;"> <span style="font-size:8px;">34</span></td> <td style="text-align:center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-01.wav(192)__ref1.wav(44)__mono_400-30.4699-20.6489-0.5469.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109');return false;"><img alt="iPod 5th - Variety - 1" src="http://soundexpert.org/documents/10179/1403301/iPod5-01.wav(192)__ref1.wav(44)__mono_400-30.4699-20.6489-0.5469.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-02.wav(192)__ref2.wav(44)__mono_400-31.6282-16.7486-5.0098.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=851,height=109');return false;"><img alt="iPod 5th - Variety - 2" src="http://soundexpert.org/documents/10179/1403301/iPod5-02.wav(192)__ref2.wav(44)__mono_400-31.6282-16.7486-5.0098.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-03.wav(192)__ref3.wav(44)__mono_400-23.4016-15.9652-6.8888.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109');return false;"><img alt="iPod 5th - Variety - 3" src="http://soundexpert.org/documents/10179/1403301/iPod5-03.wav(192)__ref3.wav(44)__mono_400-23.4016-15.9652-6.8888.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-04.wav(192)__ref4.wav(44)__mono_400-31.0432-23.2037-13.5675.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109');return false;"><img alt="iPod 5th - Variety - 4" src="http://soundexpert.org/documents/10179/1403301/iPod5-04.wav(192)__ref4.wav(44)__mono_400-31.0432-23.2037-13.5675.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-05.wav(192)__ref5.wav(44)__mono_400-35.0538-16.7379-8.8951.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=848,height=109');return false;"><img alt="iPod 5th - Variety - 5" src="http://soundexpert.org/documents/10179/1403301/iPod5-05.wav(192)__ref5.wav(44)__mono_400-35.0538-16.7379-8.8951.png" style="width:31px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-06.wav(192)__ref6.wav(44)__mono_400-31.4328-17.2911-9.8832.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109');return false;"><img alt="iPod 5th - Variety - 6" src="http://soundexpert.org/documents/10179/1403301/iPod5-06.wav(192)__ref6.wav(44)__mono_400-31.4328-17.2911-9.8832.png" style="width:26px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-07.wav(192)__ref7.wav(44)__mono_400-33.3250-22.4616-16.4660.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109');return false;"><img alt="iPod 5th - Variety - 7" src="http://soundexpert.org/documents/10179/1403301/iPod5-07.wav(192)__ref7.wav(44)__mono_400-33.3250-22.4616-16.4660.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-08.wav(192)__ref8.wav(44)__mono_400-22.8465-16.3274-7.7172.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109');return false;"><img alt="iPod 5th - Variety - 8" src="http://soundexpert.org/documents/10179/1403301/iPod5-08.wav(192)__ref8.wav(44)__mono_400-22.8465-16.3274-7.7172.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-09.wav(192)__ref9.wav(44)__mono_400-33.2010-14.2131-11.2794.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109');return false;"><img alt="iPod 5th - Variety - 9" src="http://soundexpert.org/documents/10179/1403301/iPod5-09.wav(192)__ref9.wav(44)__mono_400-33.2010-14.2131-11.2794.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-10.wav(192)__ref10.wav(44)__mono_400-23.7003-14.3339-2.5027.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109');return false;"><img alt="iPod 5th - Variety - 10" src="http://soundexpert.org/documents/10179/1403301/iPod5-10.wav(192)__ref10.wav(44)__mono_400-23.7003-14.3339-2.5027.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-11.wav(192)__ref11.wav(44)__mono_400-28.8207-20.0487-1.9347.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109');return false;"><img alt="iPod 5th - 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Variety - 25" src="http://soundexpert.org/documents/10179/1403301/iPod5-25.wav(192)__ref25.wav(44)__mono_400-27.4252-18.4647-10.1176.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-26.wav(192)__ref26.wav(44)__mono_400-35.0708-16.8534-10.6444.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109');return false;"><img alt="iPod 5th - Variety - 26" src="http://soundexpert.org/documents/10179/1403301/iPod5-26.wav(192)__ref26.wav(44)__mono_400-35.0708-16.8534-10.6444.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-27.wav(192)__ref27.wav(44)__mono_400-39.1463-15.0031-2.1247.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109');return false;"><img alt="iPod 5th - Variety - 27" src="http://soundexpert.org/documents/10179/1403301/iPod5-27.wav(192)__ref27.wav(44)__mono_400-39.1463-15.0031-2.1247.png" style="width:30px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-28.wav(192)__ref28.wav(44)__mono_400-39.8078-11.1503-9.3620.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109');return false;"><img alt="iPod 5th - Variety - 28" src="http://soundexpert.org/documents/10179/1403301/iPod5-28.wav(192)__ref28.wav(44)__mono_400-39.8078-11.1503-9.3620.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-29.wav(192)__ref29.wav(44)__mono_400-23.7256-16.7645-10.6445.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109');return false;"><img alt="iPod 5th - Variety - 29" src="http://soundexpert.org/documents/10179/1403301/iPod5-29.wav(192)__ref29.wav(44)__mono_400-23.7256-16.7645-10.6445.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-30.wav(192)__ref30.wav(44)__mono_400-30.0093-17.5956-3.0336.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109');return false;"><img alt="iPod 5th - Variety - 30" src="http://soundexpert.org/documents/10179/1403301/iPod5-30.wav(192)__ref30.wav(44)__mono_400-30.0093-17.5956-3.0336.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-31.wav(192)__ref31.wav(44)__mono_400-27.6871-16.6779-8.3974.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109');return false;"><img alt="iPod 5th - Variety - 31" src="http://soundexpert.org/documents/10179/1403301/iPod5-31.wav(192)__ref31.wav(44)__mono_400-27.6871-16.6779-8.3974.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-32.wav(192)__ref32.wav(44)__mono_400-30.7702-12.0178-6.5302.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109');return false;"><img alt="iPod 5th - Variety - 32" src="http://soundexpert.org/documents/10179/1403301/iPod5-32.wav(192)__ref32.wav(44)__mono_400-30.7702-12.0178-6.5302.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-33.wav(192)__ref33.wav(44)__mono_400-32.3281-24.2130-5.6944.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109');return false;"><img alt="iPod 5th - Variety - 33" src="http://soundexpert.org/documents/10179/1403301/iPod5-33.wav(192)__ref33.wav(44)__mono_400-32.3281-24.2130-5.6944.png" style="width:25px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-34.wav(192)__ref34.wav(44)__mono_400-43.8475-17.2155-10.8228.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109');return false;"><img alt="iPod 5th - Variety - 34" src="http://soundexpert.org/documents/10179/1403301/iPod5-34.wav(192)__ref34.wav(44)__mono_400-43.8475-17.2155-10.8228.png" style="width:30px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1403301/iPod5-35.wav(192)__ref35.wav(44)__mono_400-34.9451-19.6155-15.8121.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109');return false;"><img alt="iPod 5th - Variety - 35" src="http://soundexpert.org/documents/10179/1403301/iPod5-35.wav(192)__ref35.wav(44)__mono_400-34.9451-19.6155-15.8121.png" style="width:25px;height:99px;" /></a></td> </tr> <tr> <td style="text-align:center;"> <span style="font-size:8px;">-20.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-17.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-22.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-14.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-14.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-20.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-15.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-18.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-17.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-18.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-28.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-14.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-17.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-11.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-18.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-15.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-11.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-17.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-16.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-12.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-17.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-19.6</span></td> </tr> </tbody> </table> <br /> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> <strong>Figure 3. </strong>Diffrograms of 35 tracks of <a href="http://soundexpert.org/test-signals#variety">the test set “Variety”</a>, played back through iPod 5th (Video). They show level of waveform degradation of the musical signal divided into 400ms chunks (one pixel each, max. degradation is Red). Median Df values of the tracks are indicated. Click a track to open in full size for quick comparison with similar tracks from another device. More about diffrograms → <a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion">Diffrogram: visualization of signal differences in audio research</a>.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="text-align: left;"> <strong>Figure 4</strong>. Dendrogram showing similarity of artifact signatures of tested players. The shorter the link between two players, the more similar their artifact signatures.</td> <td> <p style="margin-left: 40px;"> <img alt="Dendrogram showing similarity of artifact signatures of tested players" src="http://soundexpert.org/documents/10179/1403301/dendrogram-port-players-9.png/ce19a127-a2e5-4993-b2e6-e8b6c99fe85b?t=1558356346000" style="width: 801px; height: 500px;" /></p> </td> </tr> </tbody> </table> <p> </p> <p> It looks like <em>average</em> linkage for the dendrogram better reveals clusterization of players according to their artifact signatures. So it will be used instead of <em>complete</em> linkage from now on.</p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> <table> <caption style="text-align: left; margin-left: 40px;"> <strong>Table 1</strong>. Underlying matrix of Spearman distances between artifact signatures for the dendrogramm. The Spearman distance = 0.1 is critical for relation of Df measurements to subjective scores. For the players that have similar artifact signatures (distance < 0.1) their perceived sound quality correlates well to df-measurements performed with substantial amount of real-life music material (histogram medians).</caption> <tbody> <tr> <td> </td> <td> <code> (1) (2) (3) (4) (5) (6) (7) (8) (9)</code></td> </tr> <tr> <td> <code> (1) Apple iPad mini 2<br /> (2) HTC Desire C<br /> (3) HTC Desire C (ba)<br /> (4) Shanling M2s<br /> (5) Shanling M2s (HighGain)<br /> (6) Shanling M2s (gradual)<br /> (7) Apple A1749 adapter<br /> (8) OnePlus 6<br /> (9) Apple iPod 5th (Video)</code></td> <td> <code><code> </code>0 0.0619 0.0972 0.0445 0.0446 0.0334 0.0374 0.0111 0.0578<br /> 0.0619 0 0.0655 0.0149 0.0147 0.0174 0.1494 0.1029 0.0017<br /> 0.0972 0.0655 0 0.0651 0.0651 0.0660 0.1710 0.1306 0.0612<br /> 0.0445 0.0149 0.0651 0 0.0002 0.0024 0.1378 0.0887 0.0112<br /> 0.0446 0.0147 0.0651 0.0002 0 0.0025 0.1379 0.0888 0.0110<br /> 0.0334 0.0174 0.0660 0.0024 0.0025 0 0.1229 0.0752 0.0140<br /> 0.0374 0.1494 0.1710 0.1378 0.1379 0.1229 0 0.0095 0.1455<br /> 0.0111 0.1029 0.1306 0.0887 0.0888 0.0752 0.0095 0 0.0988<br /> 0.0578 0.0017 0.0612 0.0112 0.0110 0.0140 0.1455 0.0988 0</code></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> </p>Serge Smirnoff2019-05-17T10:30:00ZAudio quality of OnePlus 6Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-oneplus-62021-04-16T19:53:45Z2019-01-24T19:27:00Z<p> <img alt="Recording of SE test sequences, played back by OnePlus 6 smartphone" src="http://soundexpert.org/documents/10179/1269173/se-test-oneplus6.jpg/9851ad72-82e6-4b6e-87c7-5f2d27cd84d0?t=1548423109000" style="width: 1000px; height: 750px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 1</strong>. Recording of SE test sequences, played back by OnePlus 6 smartphone. Standard SE test sequence includes 10 test signals and two hours of music material.</p> <p> </p> <p> Thanks to Kostya, who has shared his OnePlus 6 smartphone for testing, we have its objective audio measurements, preformed in accordance with SE df-metric:</p> <p> <img alt="Df-slide showing location of various test signals (including 2 hours of music) on Df scale according to their levels of degradation" src="http://soundexpert.org/documents/10179/296478/OnePlus6%40SE.png/6b855183-6dd6-42f7-bf77-064c6dd7e709?t=1548360269000" style="width: 1000px; height: 500px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 2</strong>. Df-slide showing location of various test signals (including 2 hours of music) on Df scale according to their levels of degradation. Artifact signature of OnePlus 6 is similar to the one of Apple portable devices. Df-slides of various players can be compared to each other on the <a href="http://soundexpert.org/portable-players-beta2">Portable players</a> page.</p> <p> </p> <p> <strong>Conclusion:</strong></p> <p> <strong>Audio quality of OnePlus 6 is in line with top smartphones, including Apple iPhones. They all sound similar, at least with 32 Ohm headphones.</strong></p> <br /> <p> </p> <h3> Appendix</h3> <p> </p> <p> <strong>1. Diffrograms of 35 tracks</strong> of <a href="http://soundexpert.org/test-signals#variety">the test set “Variety”</a>, played back through OnePlus 6 smartphone. They show level of waveform degradation of the musical signal divided into 400ms chunks (one pixel each). Median Df values of the tracks are indicated. Click a track to open in full size for quick comparison with similar tracks from another device. More about diffrograms → <a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion">Diffrogram: visualization of signal differences in audio research</a>.</p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align:left;"> <strong>All-off</strong></caption> <tbody> <tr> <td style="text-align:center;"> <span style="font-size:8px;">1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">10</span></td> <td style="text-align:center;"> <span style="font-size:8px;">11</span></td> <td style="text-align:center;"> <span style="font-size:8px;">12</span></td> <td style="text-align:center;"> <span style="font-size:8px;">13</span></td> <td style="text-align:center;"> <span style="font-size:8px;">14</span></td> <td style="text-align:center;"> <span style="font-size:8px;">15</span></td> <td style="text-align:center;"> <span style="font-size:8px;">16</span></td> <td style="text-align:center;"> <span style="font-size:8px;">17</span></td> <td style="text-align:center;"> <span style="font-size:8px;">18</span></td> <td style="text-align:center;"> <span style="font-size:8px;">19</span></td> <td style="text-align:center;"> <span style="font-size:8px;">20</span></td> <td style="text-align:center;"> <span style="font-size:8px;">21</span></td> <td style="text-align:center;"> <span style="font-size:8px;">22</span></td> <td style="text-align:center;"> <span style="font-size:8px;">23</span></td> <td style="text-align:center;"> <span style="font-size:8px;">24</span></td> <td style="text-align:center;"> <span style="font-size:8px;">25</span></td> <td style="text-align:center;"> <span style="font-size:8px;">26</span></td> <td style="text-align:center;"> <span style="font-size:8px;">27</span></td> <td style="text-align:center;"> <span style="font-size:8px;">28</span></td> <td style="text-align:center;"> <span style="font-size:8px;">29</span></td> <td style="text-align:center;"> <span style="font-size:8px;">30</span></td> <td style="text-align:center;"> <span style="font-size:8px;">31</span></td> <td style="text-align:center;"> <span style="font-size:8px;">32</span></td> <td style="text-align:center;"> <span style="font-size:8px;">33</span></td> <td style="text-align:center;"> <span style="font-size:8px;">34</span></td> <td style="text-align:center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-01.wav%28192%29__ref1.wav%2844%29__mono_400-38.8280-30.0749%2B0.9353.png/e618d7ab-0843-45b3-b8e0-119285c648ad?t=1548434366000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109'); return false;"><img alt="OnePlus6 - Variety - 1" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-01.wav%28192%29__ref1.wav%2844%29__mono_400-38.8280-30.0749%2B0.9353.png/e618d7ab-0843-45b3-b8e0-119285c648ad?t=1548434366000" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-02.wav(192)__ref2.wav(44)__mono_400-38.5134-25.0948-4.1023.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=851,height=109');return false;"><img alt="OnePlus6 - Variety - 2" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-02.wav(192)__ref2.wav(44)__mono_400-38.5134-25.0948-4.1023.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-03.wav(192)__ref3.wav(44)__mono_400-31.2955-25.1621-6.6966.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109');return false;"><img alt="OnePlus6 - Variety - 3" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-03.wav(192)__ref3.wav(44)__mono_400-31.2955-25.1621-6.6966.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-04.wav(192)__ref4.wav(44)__mono_400-40.7280-32.8957-23.6778.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109');return false;"><img alt="OnePlus6 - Variety - 4" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-04.wav(192)__ref4.wav(44)__mono_400-40.7280-32.8957-23.6778.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-05.wav(192)__ref5.wav(44)__mono_400-41.2477-26.3404-5.2619.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=848,height=109');return false;"><img alt="OnePlus6 - Variety - 5" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-05.wav(192)__ref5.wav(44)__mono_400-41.2477-26.3404-5.2619.png" style="width:31px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-06.wav(192)__ref6.wav(44)__mono_400-40.4024-26.6566-15.6296.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109');return false;"><img alt="OnePlus6 - Variety - 6" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-06.wav(192)__ref6.wav(44)__mono_400-40.4024-26.6566-15.6296.png" style="width:26px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-07.wav(192)__ref7.wav(44)__mono_400-41.5800-31.7331-21.9647.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109');return false;"><img alt="OnePlus6 - Variety - 7" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-07.wav(192)__ref7.wav(44)__mono_400-41.5800-31.7331-21.9647.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-08.wav(192)__ref8.wav(44)__mono_400-29.5073-24.6443-14.5375.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109');return false;"><img alt="OnePlus6 - Variety - 8" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-08.wav(192)__ref8.wav(44)__mono_400-29.5073-24.6443-14.5375.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-09.wav(192)__ref9.wav(44)__mono_400-37.4493-23.8268-21.0668.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109');return false;"><img alt="OnePlus6 - Variety - 9" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-09.wav(192)__ref9.wav(44)__mono_400-37.4493-23.8268-21.0668.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-10.wav(192)__ref10.wav(44)__mono_400-33.7710-23.4971-2.0180.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109');return false;"><img alt="OnePlus6 - Variety - 10" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-10.wav(192)__ref10.wav(44)__mono_400-33.7710-23.4971-2.0180.png" style="width:31px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-11.wav(192)__ref11.wav(44)__mono_400-38.2632-27.5642-2.0600.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109');return false;"><img alt="OnePlus6 - Variety - 11" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-11.wav(192)__ref11.wav(44)__mono_400-38.2632-27.5642-2.0600.png" style="width:28px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-12.wav(192)__ref12.wav(44)__mono_400-35.9246-22.8601-8.7925.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=586,height=109');return false;"><img alt="OnePlus6 - Variety - 12" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-12.wav(192)__ref12.wav(44)__mono_400-35.9246-22.8601-8.7925.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-13.wav(192)__ref13.wav(44)__mono_400-33.4267-22.9907-11.4852.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=655,height=109');return false;"><img alt="OnePlus6 - Variety - 13" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-13.wav(192)__ref13.wav(44)__mono_400-33.4267-22.9907-11.4852.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-14.wav(192)__ref14.wav(44)__mono_400-40.8528-27.6079-8.0801.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=289,height=109');return false;"><img alt="OnePlus6 - Variety - 14" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-14.wav(192)__ref14.wav(44)__mono_400-40.8528-27.6079-8.0801.png" style="width:25px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-15.wav(192)__ref15.wav(44)__mono_400-43.3408-35.3571-3.2061.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=483,height=109');return false;"><img alt="OnePlus6 - Variety - 15" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-15.wav(192)__ref15.wav(44)__mono_400-43.3408-35.3571-3.2061.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-16.wav(192)__ref16.wav(44)__mono_400-36.8729-26.0179-2.4411.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109');return false;"><img alt="OnePlus6 - Variety - 16" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-16.wav(192)__ref16.wav(44)__mono_400-36.8729-26.0179-2.4411.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-17.wav(192)__ref17.wav(44)__mono_400-37.6667-29.1621-3.8758.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109');return false;"><img alt="OnePlus6 - Variety - 17" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-17.wav(192)__ref17.wav(44)__mono_400-37.6667-29.1621-3.8758.png" style="width:25px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-18.wav(192)__ref18.wav(44)__mono_400-30.7426-25.2271-11.6083.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=680,height=109');return false;"><img alt="OnePlus6 - Variety - 18" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-18.wav(192)__ref18.wav(44)__mono_400-30.7426-25.2271-11.6083.png" style="width:29px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-19.wav(192)__ref19.wav(44)__mono_400-43.0347-32.8778-10.8333.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=401,height=109');return false;"><img alt="OnePlus6 - Variety - 19" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-19.wav(192)__ref19.wav(44)__mono_400-43.0347-32.8778-10.8333.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-20.wav(192)__ref20.wav(44)__mono_400-53.7318-37.8306-12.5565.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109');return false;"><img alt="OnePlus6 - Variety - 20" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-20.wav(192)__ref20.wav(44)__mono_400-53.7318-37.8306-12.5565.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-21.wav(192)__ref21.wav(44)__mono_400-38.3507-31.3891-7.3358.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109');return false;"><img alt="OnePlus6 - Variety - 21" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-21.wav(192)__ref21.wav(44)__mono_400-38.3507-31.3891-7.3358.png" style="width:27px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-22.wav(192)__ref22.wav(44)__mono_400-33.5078-23.4260-14.4393.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109');return false;"><img alt="OnePlus6 - Variety - 22" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-22.wav(192)__ref22.wav(44)__mono_400-33.5078-23.4260-14.4393.png" style="width:28px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-23.wav(192)__ref23.wav(44)__mono_400-34.9532-24.9511-19.9153.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109');return false;"><img alt="OnePlus6 - Variety - 23" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-23.wav(192)__ref23.wav(44)__mono_400-34.9532-24.9511-19.9153.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-24.wav(192)__ref24.wav(44)__mono_400-30.9685-21.3456-19.3096.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109');return false;"><img alt="OnePlus6 - Variety - 24" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-24.wav(192)__ref24.wav(44)__mono_400-30.9685-21.3456-19.3096.png" style="width:29px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-25.wav(192)__ref25.wav(44)__mono_400-35.9646-27.2274-19.2629.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109');return false;"><img alt="OnePlus6 - Variety - 25" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-25.wav(192)__ref25.wav(44)__mono_400-35.9646-27.2274-19.2629.png" style="width:29px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-26.wav(192)__ref26.wav(44)__mono_400-43.3924-26.7601-12.0750.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109');return false;"><img alt="OnePlus6 - Variety - 26" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-26.wav(192)__ref26.wav(44)__mono_400-43.3924-26.7601-12.0750.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-27.wav(192)__ref27.wav(44)__mono_400-48.1607-23.6624-0.9096.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109');return false;"><img alt="OnePlus6 - Variety - 27" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-27.wav(192)__ref27.wav(44)__mono_400-48.1607-23.6624-0.9096.png" style="width:30px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-28.wav(192)__ref28.wav(44)__mono_400-46.5406-20.5836-11.1011.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109');return false;"><img alt="OnePlus6 - Variety - 28" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-28.wav(192)__ref28.wav(44)__mono_400-46.5406-20.5836-11.1011.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-29.wav(192)__ref29.wav(44)__mono_400-33.3676-26.5589-20.4337.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109');return false;"><img alt="OnePlus6 - Variety - 29" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-29.wav(192)__ref29.wav(44)__mono_400-33.3676-26.5589-20.4337.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-30.wav(192)__ref30.wav(44)__mono_400-35.3807-25.9532-10.7292.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109');return false;"><img alt="OnePlus6 - Variety - 30" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-30.wav(192)__ref30.wav(44)__mono_400-35.3807-25.9532-10.7292.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-31.wav(192)__ref31.wav(44)__mono_400-35.3691-25.6988-6.7129.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109');return false;"><img alt="OnePlus6 - Variety - 31" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-31.wav(192)__ref31.wav(44)__mono_400-35.3691-25.6988-6.7129.png" style="width:26px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-32.wav(192)__ref32.wav(44)__mono_400-39.8361-20.7636-8.9073.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109');return false;"><img alt="OnePlus6 - Variety - 32" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-32.wav(192)__ref32.wav(44)__mono_400-39.8361-20.7636-8.9073.png" style="width:27px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-33.wav(192)__ref33.wav(44)__mono_400-41.1936-34.1271-11.9081.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109');return false;"><img alt="OnePlus6 - Variety - 33" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-33.wav(192)__ref33.wav(44)__mono_400-41.1936-34.1271-11.9081.png" style="width:25px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-34.wav(192)__ref34.wav(44)__mono_400-37.2526-25.5031-10.9224.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109');return false;"><img alt="OnePlus6 - Variety - 34" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-34.wav(192)__ref34.wav(44)__mono_400-37.2526-25.5031-10.9224.png" style="width:30px;margin-left:1px;margin-right:1px;height:99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1269173/OnePlus6-35.wav(192)__ref35.wav(44)__mono_400-41.7643-28.2155-24.4459.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109');return false;"><img alt="OnePlus6 - Variety - 35" src="http://soundexpert.org/documents/10179/1269173/OnePlus6-35.wav(192)__ref35.wav(44)__mono_400-41.7643-28.2155-24.4459.png" style="width:25px;height:99px;" /></a></td> </tr> <tr> <td style="text-align:center;"> <span style="font-size:8px;">-30.1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-32.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-31.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-24.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-27.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-22.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-27.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-35.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-29.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-32.9</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-37.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-31.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.4</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-21.3</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-27.2</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-23.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-20.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.6</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.7</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-20.8</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-34.1</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align:center;"> <span style="font-size:8px;">-28.2</span></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> <strong>2. Dendrogram of similarity of artifact signatures</strong> for the portable players.</p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="text-align: left;"> <img alt="Dendrogram showing similarity of artifact signatures of tested players" src="http://soundexpert.org/documents/10179/1269173/dendrogram-similarity-players-8.png/1e6b7c6b-2cb2-44f8-94f2-b07041c8b70b?t=1548423935000" style="width: 700px; height: 460px;" /></td> <td> <p style="margin-left: 40px;"> <strong>Figure 7</strong>. Dendrogram showing similarity of artifact signatures of tested players. The shorter the link between two players, the more similar their artifact signatures.</p> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> <table> <caption style="text-align: left; margin-left: 40px;"> <strong>Table 1</strong>. Underlying matrix of Spearman distances between artifact signatures for the dendrogramm. The Spearman distance = 0.1 is critical for relation of Df measurements to subjective scores. For the players that have similar artifact signatures (distance < 0.1) their perceived sound quality correlates well to df-measurements performed with substantial amount of real-life music material (histogram medians).</caption> <tbody> <tr> <td> </td> <td> <code> (1) (2) (3) (4) (5) (6) (7) (8)</code></td> </tr> <tr> <td> <code> (1) Apple iPad mini 2<br /> (2) HTC Desire C<br /> (3) HTC Desire C (ba)<br /> (4) Shanling M2s<br /> (5) Shanling M2s (HighGain)<br /> (6) Shanling M2s (gradual)<br /> (7) Apple A1749 adapter<br /> (8) OnePlus 6</code></td> <td> <code> 0.0619 0.0972 0.0445 0.0446 0.0334 0.0374 0.0111<br /> 0.0619 0.0655 0.0149 0.0147 0.0174 0.1494 0.1029<br /> 0.0972 0.0655 0.0651 0.0651 0.0660 0.1710 0.1306<br /> 0.0445 0.0149 0.0651 0.0002 0.0024 0.1378 0.0887<br /> 0.0446 0.0147 0.0651 0.0002 0.0025 0.1379 0.0888<br /> 0.0334 0.0174 0.0660 0.0024 0.0025 0.1229 0.0752<br /> 0.0374 0.1494 0.1710 0.1378 0.1379 0.1229 0.0095<br /> 0.0111 0.1029 0.1306 0.0887 0.0888 0.0752 0.0095 </code></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> </p>Serge Smirnoff2019-01-24T19:27:00ZAudio quality of Apple Lightning to 3.5mm Headphone Jack AdapterSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-lightning-to-3-5mm-headphone-jack-adapter2021-06-13T20:07:29Z2019-01-12T13:05:00Z<div class="portlet-msg-info"> This adapter has been tested recently with more accurate measurement setup - <a href="http://soundexpert.org/vault/dpa.html#apple-a1749">http://soundexpert.org/vault/dpa.html#apple-a1749</a></div> <p> </p> <table> <tbody> <tr> <td> <img alt="Apple adapter A1749" src="http://soundexpert.org/documents/10179/1253940/A1749.jpg/8b954432-e94a-44e1-b8ee-b1bc9c58afe9?t=1547296862000" style="width: 450px; height: 450px;" /></td> <td> <p style="margin-left: 80px;"> <strong>Figure 1</strong>. Apple adapter A1749</p> </td> </tr> </tbody> </table> <p> </p> <p> Lightning to 3.5mm adapter (A1749) is a solution Apple offers after disappearing headphone jack from iPhones. The features of the adapter in short:<br /> <br /> 1. Mass audio product, supplied with every iPhone without headphone jack.<br /> 2. Retail price is $9.<br /> 3. DAC+headphone amplifier are inside lightning connector (see <strong>Fig.2</strong> and <a href="https://www.ifixit.com/Teardown/Apple+Lightning+to+Headphone+Jack+Adapter+Teardown/67562" target="_blank">the teardown at IFIXIT</a>).</p> <p style="text-align: right;"> <img alt="X-ray image of Apple’s A1749 adapter by Creative Electron" src="http://soundexpert.org/documents/10179/1253940/A1749-x-ray.jpg/019980a0-c8d0-4559-ae9a-2e548b256d4d?t=1547297272000" style="width: 1000px; height: 150px;" /> <strong>Figure 2</strong>. <a href="https://creativeelectron.com/2016/10/05/inside-apples-new-audio-adapter/" target="_blank">X-ray image of Apple’s A1749 adapter</a> by Creative Electron</p> <p> 4. Surprisingly good traditional audio measurements made by <a href="https://www.kenrockwell.com/apple/lightning-adapter-audio-quality.htm" target="_blank">Ken Rockwell</a> and <a href="http://archimago.blogspot.com/2018/01/measurements-apples-lightning-to-35mm.html" target="_blank">Archimago</a>.</p> <p> </p> <p> </p> <table style="width:100%;"> <tbody> <tr> <td> <p style="margin-left: 40px;"> <strong>Figure 3</strong>. SE measurement procedure is mainly the recording of some test sequences, played by device under test. Standard SE test sequence includes 10 test signals and two hours of various music material.</p> </td> <td style="text-align: right;"> <img alt="Recording of SE test sequences through A1749 adapter" src="http://soundexpert.org/documents/10179/1253940/se-testing-a1749.jpg/e048291c-cc94-4554-970c-afef7517f416?t=1547297893000" style="width: 500px; height: 300px; margin-left: 20px; margin-right: 20px;" /></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> Results of standard SE df-measurements of the adapter:</p> <p> <img alt="Df-slide with results of testing A1749" src="http://soundexpert.org/documents/10179/296478/AppleA1749%40SE.png/cf939a1c-95e2-47c4-8644-f0899b747284?t=1546183012000" style="width: 1000px; height: 500px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 4</strong>. Df-slide with results of testing A1749. Df-slides of various devices can be compared to each other on the <a href="http://soundexpert.org/portable-players-beta2">Portable players</a> page.</p> <p> </p> <p> The adapter was tested with iPad mini. The latter has been tested earlier, its df-slide is below:</p> <p> <img alt="Df-slide with results of testing iPad mini 2" src="http://soundexpert.org/documents/10179/296478/AppleiPadMini2%40SE.png/2e30e284-9e00-48a4-8b1f-2885ebcdd474?t=1546679958000" style="width: 1000px; height: 500px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 5</strong>. Df-slide with results of testing iPad mini 2, which was used as a host for testing A1749 adapter.</p> <p> </p> <table style="width:100%;"> <tbody> <tr> <td> <img alt="Enlarged version of Sine12.5kHz diffrogram from Fig.4" src="http://soundexpert.org/documents/10179/1253940/tech03_02.wav%28192%29__ref_tech03_02.wav%2844%29__mono_400-73.6890-64.5285-56.2297.png/695125cf-9871-4d5e-9906-e9f02dc0fe14?t=1547298690000" style="width: 300px; height: 396px;" /></td> <td> <p style="margin-left: 40px;"> <strong>Figure 6</strong>. Enlarged version of Sine12.5kHz diffrogram from <strong>Fig.4</strong>. Vertical “greener” lines show time inconsistency of the output signal. <strong>This is how jitter looks like</strong>.</p> </td> </tr> </tbody> </table> <p> </p> <p> <strong>Conclusions:</strong></p> <p> <strong>(1)</strong> Artifact/sound signatures of both the adapter and iPad mini are similar (close Df values and their relative positions, similar histograms). The adapter utilizes the same audio solution that is used in iPhones 4/5/6 and other portable audio devices by Apple.</p> <p> <strong>(2)</strong> Vertical stripes on Sine12.5kHz diffrogram in <strong>Fig.4</strong> (enlarged version - <strong>Fig.6</strong>) reveal small time inconsistency of the adapter's output signal (probably, clock generator of lightning interface is the source). High frequency components of a signal are affected the most by such time instability or jitter. Real-life music signal is almost not affected (+0.2dB).</p> <p> <strong>(3)</strong> Just for reference, white noise diffrogram of the adapter (<strong>Fig.4</strong>) reveales steep cut off of frequency response near Nyquist frequency.</p> <p> <strong>(4)</strong> Just for reference, in case of the adapter all SE test signals show a bit worse Df values in comparison to iPad mini. Except MOD-SMPTE 1:4 signal, which is reproduced more accurately by the adapter (-3.2dB, additional research needed).</p> <p> <strong>Audio quality of Apple Lightning to 3.5mm adapter (A1749) is almost as good as in-built mobile audio solutions by Apple, though it has slightly worse df-measurements. Mostly due to the higher jitter. But if you listen music you will not hear the difference; it is too subtle to be perceived.</strong></p> <p> </p> <p> </p> <h3> Appendix</h3> <p> </p> <p> <strong>1. Diffrograms of 35 tracks</strong> of <a href="http://soundexpert.org/test-signals#variety">the test set “Variety”</a>, played back through A1749 adapter. They show level of waveform degradation of the musical signal divided into 400ms chunks (one pixel each). Median Df values of the tracks are indicated. Click a track to open in full size for quick comparison with similar tracks from another device. More about diffrograms → <a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion">Diffrogram: visualization of signal differences in audio research</a>.</p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: left;"> <strong>All-off</strong></caption> <tbody> <tr> <td style="text-align: center;"> <span style="font-size:8px;">1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">10</span></td> <td style="text-align: center;"> <span style="font-size:8px;">11</span></td> <td style="text-align: center;"> <span style="font-size:8px;">12</span></td> <td style="text-align: center;"> <span style="font-size:8px;">13</span></td> <td style="text-align: center;"> <span style="font-size:8px;">14</span></td> <td style="text-align: center;"> <span style="font-size:8px;">15</span></td> <td style="text-align: center;"> <span style="font-size:8px;">16</span></td> <td style="text-align: center;"> <span style="font-size:8px;">17</span></td> <td style="text-align: center;"> <span style="font-size:8px;">18</span></td> <td style="text-align: center;"> <span style="font-size:8px;">19</span></td> <td style="text-align: center;"> <span style="font-size:8px;">20</span></td> <td style="text-align: center;"> <span style="font-size:8px;">21</span></td> <td style="text-align: center;"> <span style="font-size:8px;">22</span></td> <td style="text-align: center;"> <span style="font-size:8px;">23</span></td> <td style="text-align: center;"> <span style="font-size:8px;">24</span></td> <td style="text-align: center;"> <span style="font-size:8px;">25</span></td> <td style="text-align: center;"> <span style="font-size:8px;">26</span></td> <td style="text-align: center;"> <span style="font-size:8px;">27</span></td> <td style="text-align: center;"> <span style="font-size:8px;">28</span></td> <td style="text-align: center;"> <span style="font-size:8px;">29</span></td> <td style="text-align: center;"> <span style="font-size:8px;">30</span></td> <td style="text-align: center;"> <span style="font-size:8px;">31</span></td> <td style="text-align: center;"> <span style="font-size:8px;">32</span></td> <td style="text-align: center;"> <span style="font-size:8px;">33</span></td> <td style="text-align: center;"> <span style="font-size:8px;">34</span></td> <td style="text-align: center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-01.wav%28192%29__ref1.wav%2844%29__mono_400-38.5112-30.2575%2B0.7544.png/8eda8512-b3bd-4ee5-bf60-81c51f63c048?t=1547311254000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109'); 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return false;"><img alt="AppleA1749 - Variety - 5" src="http://soundexpert.org/documents/10179/1254163/A1749-05.wav(192)__ref5.wav(44)__mono_400-40.6115-26.6386-3.9412.png" style="width: 31px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-06.wav(192)__ref6.wav(44)__mono_400-40.5276-26.6919-15.3728.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109'); return false;"><img alt="AppleA1749 - Variety - 6" src="http://soundexpert.org/documents/10179/1254163/A1749-06.wav(192)__ref6.wav(44)__mono_400-40.5276-26.6919-15.3728.png" style="width: 26px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-07.wav(192)__ref7.wav(44)__mono_400-41.2030-32.0677-21.7194.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109'); return false;"><img alt="AppleA1749 - Variety - 7" src="http://soundexpert.org/documents/10179/1254163/A1749-07.wav(192)__ref7.wav(44)__mono_400-41.2030-32.0677-21.7194.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-08.wav(192)__ref8.wav(44)__mono_400-29.3464-24.3462-15.2746.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109'); return false;"><img alt="AppleA1749 - Variety - 8" src="http://soundexpert.org/documents/10179/1254163/A1749-08.wav(192)__ref8.wav(44)__mono_400-29.3464-24.3462-15.2746.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-09.wav(192)__ref9.wav(44)__mono_400-37.6943-24.1177-20.5035.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="AppleA1749 - Variety - 9" src="http://soundexpert.org/documents/10179/1254163/A1749-09.wav(192)__ref9.wav(44)__mono_400-37.6943-24.1177-20.5035.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-10.wav(192)__ref10.wav(44)__mono_400-33.1421-23.5896-2.8647.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109'); return false;"><img alt="AppleA1749 - Variety - 10" src="http://soundexpert.org/documents/10179/1254163/A1749-10.wav(192)__ref10.wav(44)__mono_400-33.1421-23.5896-2.8647.png" style="width: 31px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-11.wav(192)__ref11.wav(44)__mono_400-38.7063-26.7619-3.3272.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109'); return false;"><img alt="AppleA1749 - Variety - 11" src="http://soundexpert.org/documents/10179/1254163/A1749-11.wav(192)__ref11.wav(44)__mono_400-38.7063-26.7619-3.3272.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-12.wav(192)__ref12.wav(44)__mono_400-36.4110-22.5968-9.0657.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=586,height=109'); return false;"><img alt="AppleA1749 - Variety - 12" src="http://soundexpert.org/documents/10179/1254163/A1749-12.wav(192)__ref12.wav(44)__mono_400-36.4110-22.5968-9.0657.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-13.wav(192)__ref13.wav(44)__mono_400-33.0395-21.8870-10.4114.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=655,height=109'); return false;"><img alt="AppleA1749 - Variety - 13" src="http://soundexpert.org/documents/10179/1254163/A1749-13.wav(192)__ref13.wav(44)__mono_400-33.0395-21.8870-10.4114.png" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-14.wav(192)__ref14.wav(44)__mono_400-41.2354-27.8375-8.3037.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=289,height=109'); return false;"><img alt="AppleA1749 - Variety - 14" src="http://soundexpert.org/documents/10179/1254163/A1749-14.wav(192)__ref14.wav(44)__mono_400-41.2354-27.8375-8.3037.png" style="width: 25px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-15.wav(192)__ref15.wav(44)__mono_400-43.7943-35.8392-3.3102.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=483,height=109'); return false;"><img alt="AppleA1749 - Variety - 15" src="http://soundexpert.org/documents/10179/1254163/A1749-15.wav(192)__ref15.wav(44)__mono_400-43.7943-35.8392-3.3102.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-16.wav(192)__ref16.wav(44)__mono_400-37.0817-25.9046-3.5043.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109'); return false;"><img alt="AppleA1749 - Variety - 16" src="http://soundexpert.org/documents/10179/1254163/A1749-16.wav(192)__ref16.wav(44)__mono_400-37.0817-25.9046-3.5043.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-17.wav(192)__ref17.wav(44)__mono_400-36.7338-27.8870-3.8295.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109'); return false;"><img alt="AppleA1749 - Variety - 17" src="http://soundexpert.org/documents/10179/1254163/A1749-17.wav(192)__ref17.wav(44)__mono_400-36.7338-27.8870-3.8295.png" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-18.wav(192)__ref18.wav(44)__mono_400-29.8679-25.1611-12.3051.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=680,height=109'); return false;"><img alt="AppleA1749 - Variety - 18" src="http://soundexpert.org/documents/10179/1254163/A1749-18.wav(192)__ref18.wav(44)__mono_400-29.8679-25.1611-12.3051.png" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-19.wav(192)__ref19.wav(44)__mono_400-43.1453-33.2466-11.1963.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=401,height=109'); return false;"><img alt="AppleA1749 - Variety - 19" src="http://soundexpert.org/documents/10179/1254163/A1749-19.wav(192)__ref19.wav(44)__mono_400-43.1453-33.2466-11.1963.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-20.wav(192)__ref20.wav(44)__mono_400-53.2684-37.9276-11.5083.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109'); return false;"><img alt="AppleA1749 - Variety - 20" src="http://soundexpert.org/documents/10179/1254163/A1749-20.wav(192)__ref20.wav(44)__mono_400-53.2684-37.9276-11.5083.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-21.wav(192)__ref21.wav(44)__mono_400-38.6125-31.6268-7.3841.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109'); return false;"><img alt="AppleA1749 - Variety - 21" src="http://soundexpert.org/documents/10179/1254163/A1749-21.wav(192)__ref21.wav(44)__mono_400-38.6125-31.6268-7.3841.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-22.wav(192)__ref22.wav(44)__mono_400-33.6711-23.5504-15.2651.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="AppleA1749 - Variety - 22" src="http://soundexpert.org/documents/10179/1254163/A1749-22.wav(192)__ref22.wav(44)__mono_400-33.6711-23.5504-15.2651.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-23.wav(192)__ref23.wav(44)__mono_400-35.4352-24.5563-19.7069.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109'); return false;"><img alt="AppleA1749 - Variety - 23" src="http://soundexpert.org/documents/10179/1254163/A1749-23.wav(192)__ref23.wav(44)__mono_400-35.4352-24.5563-19.7069.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-24.wav(192)__ref24.wav(44)__mono_400-30.4904-21.7382-19.7153.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109'); return false;"><img alt="AppleA1749 - Variety - 24" src="http://soundexpert.org/documents/10179/1254163/A1749-24.wav(192)__ref24.wav(44)__mono_400-30.4904-21.7382-19.7153.png" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-25.wav(192)__ref25.wav(44)__mono_400-36.0778-27.2893-18.8757.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109'); return false;"><img alt="AppleA1749 - Variety - 25" src="http://soundexpert.org/documents/10179/1254163/A1749-25.wav(192)__ref25.wav(44)__mono_400-36.0778-27.2893-18.8757.png" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-26.wav(192)__ref26.wav(44)__mono_400-43.7257-27.1785-13.6016.png onclick=" resizable="no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109');" return=""><img alt="AppleA1749 - Variety - 26" src="http://soundexpert.org/documents/10179/1254163/A1749-26.wav(192)__ref26.wav(44)__mono_400-43.7257-27.1785-13.6016.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-27.wav(192)__ref27.wav(44)__mono_400-48.2511-24.0112-1.3164.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109'); return false;"><img alt="AppleA1749 - Variety - 27" src="http://soundexpert.org/documents/10179/1254163/A1749-27.wav(192)__ref27.wav(44)__mono_400-48.2511-24.0112-1.3164.png" style="width: 30px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-28.wav(192)__ref28.wav(44)__mono_400-45.8735-20.9072-11.9667.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109'); return false;"><img alt="AppleA1749 - Variety - 28" src="http://soundexpert.org/documents/10179/1254163/A1749-28.wav(192)__ref28.wav(44)__mono_400-45.8735-20.9072-11.9667.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-29.wav(192)__ref29.wav(44)__mono_400-33.6738-26.9864-20.8416.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109'); return false;"><img alt="AppleA1749 - Variety - 29" src="http://soundexpert.org/documents/10179/1254163/A1749-29.wav(192)__ref29.wav(44)__mono_400-33.6738-26.9864-20.8416.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-30.wav(192)__ref30.wav(44)__mono_400-35.4187-26.0300-11.0466.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109'); return false;"><img alt="AppleA1749 - Variety - 30" src="http://soundexpert.org/documents/10179/1254163/A1749-30.wav(192)__ref30.wav(44)__mono_400-35.4187-26.0300-11.0466.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-31.wav(192)__ref31.wav(44)__mono_400-35.7714-25.7963-7.6269.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109'); return false;"><img alt="AppleA1749 - Variety - 31" src="http://soundexpert.org/documents/10179/1254163/A1749-31.wav(192)__ref31.wav(44)__mono_400-35.7714-25.7963-7.6269.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-32.wav(192)__ref32.wav(44)__mono_400-40.6954-21.1189-8.7912.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109'); return false;"><img alt="AppleA1749 - Variety - 32" src="http://soundexpert.org/documents/10179/1254163/A1749-32.wav(192)__ref32.wav(44)__mono_400-40.6954-21.1189-8.7912.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-33.wav(192)__ref33.wav(44)__mono_400-42.1350-34.5971-12.7581.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109'); return false;"><img alt="AppleA1749 - Variety - 33" src="http://soundexpert.org/documents/10179/1254163/A1749-33.wav(192)__ref33.wav(44)__mono_400-42.1350-34.5971-12.7581.png" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-34.wav(192)__ref34.wav(44)__mono_400-37.4281-25.2653-10.8367.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109'); return false;"><img alt="AppleA1749 - Variety - 34" src="http://soundexpert.org/documents/10179/1254163/A1749-34.wav(192)__ref34.wav(44)__mono_400-37.4281-25.2653-10.8367.png" style="width: 30px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1254163/A1749-35.wav(192)__ref35.wav(44)__mono_400-41.2061-27.8678-23.8213.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109'); return false;"><img alt="AppleA1749 - Variety - 35" src="http://soundexpert.org/documents/10179/1254163/A1749-35.wav(192)__ref35.wav(44)__mono_400-41.2061-27.8678-23.8213.png" style="width: 25px; height: 99px;" /></a></td> </tr> <tr> <td style="text-align: center;"> <span style="font-size:8px;">-30.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-33.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-21.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-35.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-33.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-37.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-21.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-20.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-21.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-34.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.9</span></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> <strong>2. Dendrogram of similarity of artifact signatures</strong> for the portable players.</p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="text-align: left;"> <img alt="Dendrogram showing similarity of artifact signatures of tested players" src="http://soundexpert.org/documents/10179/1254163/dendrogram-similarity-players-7.png/d47eb4fd-c0dc-4824-af1b-8d3dc9b6347d?t=1547325462102" style="width: 700px; height: 460px;" /></td> <td> <p style="margin-left: 40px;"> <strong>Figure 7</strong>. Dendrogram showing similarity of artifact signatures of tested players. The shorter the link between two players, the more similar their artifact signatures. The Spearman distance = 0.1 is critical for relation of Df measurements to subjective scores. For those players which have similar artifact signatures (distance < 0.1) their perceived sound quality correlates well to df-measurements with substantial amount of real-life music material (histogram medians).</p> </td> </tr> </tbody> </table> <p> </p> <p> The similarity dendrogramm is a bit misleading in this case (cophenetic coef. = 0.74). There should be a better instrument for visualization of non-euclidean distances between objects. Until then underlying matrix of distances will accompany each dendrogram (<strong>Table 1</strong>).</p> <p style="margin-left: 40px;"> <strong>Table 1</strong>. Matrix of distances (Spearman) between artifact signatures of the players.</p> <table> <tbody> <tr> <td> </td> <td> <code> (1) (2) (3) (4) (5) (6) (7)</code></td> </tr> <tr> <td> <code> (1) Apple iPad mini 2<br /> (2) HTC Desire C<br /> (3) HTC Desire C (ba)<br /> (4) Shanling M2s<br /> (5) Shanling M2s (HighGain)<br /> (6) Shanling M2s (gradual)<br /> (7) Apple A1749 adapter</code></td> <td> <code> 0 0.0619 0.0972 0.0445 0.0446 0.0334 0.0374<br /> 0.0619 0 0.0655 0.0149 0.0147 0.0174 0.1494<br /> 0.0972 0.0655 0 0.0651 0.0651 0.0660 0.1710<br /> 0.0445 0.0149 0.0651 0 0.0002 0.0024 0.1378<br /> 0.0446 0.0147 0.0651 0.0002 0 0.0025 0.1379<br /> 0.0334 0.0174 0.0660 0.0024 0.0025 0 0.1229<br /> 0.0374 0.1494 0.1710 0.1378 0.1379 0.1229 0</code></td> </tr> </tbody> </table> <p> </p> <p> From the table, A1749 adapter can be safely compared to iPad mini 2 using df-measurements because they have similar artifact signatures (distance = 0.0374 < 0.1). Comparison of A1749 with other tested devices is questionable as their artifact signatures differ to greater extent (additional research needed).</p> <p> </p>Serge Smirnoff2019-01-12T13:05:00ZAudio quality of Shanling M2sSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-shanling-m2s2021-04-16T19:50:37Z2018-12-03T16:27:00Z<img alt="Portable player M2s kindly offered for testing by Alexey Silich" src="http://soundexpert.org/documents/10179/1131562/header-shanlingm2s.jpg/eb9336f5-6382-4947-ad84-a74fc7c27323?t=1544630243000" style="width: 1000px; height: 500px;" /> <p style="margin-left: 80px;"> <strong>Figure 1</strong>: Portable player M2s kindly offered for testing by <a href="https://www.facebook.com/profile.php?id=100000479423044" target="_blank">Alexey Silich</a>.</p> <p> </p> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="padding-right: 40px;"> <p> Thanks to Alexey we start our collection of tested devices with portable music player M2s by Shanling Audio. Overview of the player with technical specifications can be found on the manufacturer's website → <a href="http://www.shanling.com/Product/Detail?id=2de2216f17334b2dbaa4377d95d65550" target="_blank">M2s portable music player</a>.</p> <p> We performed standard df-measurements with technical signals and real music material.</p> <p> The player has two settings which have unclear impact on perceived sound quality:</p> <ul> <li> Gain Setting: Low / High</li> <li> Lopass filter mode: steep / gradual</li> </ul> <p> In order to find out that, M2s was tested in three modes:</p> <ul> <li> <strong>All-off</strong>: Low Gain - steep lowpass filter</li> <li> <strong>HighGain</strong>: High Gain - steep lowpass filter</li> <li> <strong>gradual</strong>: Low Gain - gradual lowpass filter</li> </ul> <p> The following three df-slides show level of waveform degradation in these modes. The most meaningful value on df-slide is histogram median, which is assumed to correlate well to perceived sound quality (<a href="http://soundexpert.org/articles/-/blogs/objective-difference-measurements-to-predict-listening-test-results-">the research</a> is still in progress). The less the value, the higher playback fidelity.</p> </td> <td> <img alt="Recording of SE test sequences from headphone jack of M2s portable player" src="http://soundexpert.org/documents/10179/1131562/testing-shanlingm2s.jpg/8a95edf1-de55-4cd5-ae4a-1f264a3baf9a?t=1544630742000" style="width: 500px; height: 418px;" /> <p style="margin-left: 40px;"> <strong>Figure 2</strong>: Recording of SE test sequences from headphone jack of M2s portable player.</p> </td> </tr> </tbody> </table> <p> </p> <p> <img alt="Shanling M2s df-slide (All-off)" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s%40SE.png/419b8018-26ee-49bc-96f6-d52814f84d65?t=1544640440000" style="width: 1000px; height: 500px;" /></p> <p> <img alt="Shanling M2s df-slide (HighGain)" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG%40SE.png/e0ae19b2-efea-436f-a6fc-8f1bc4c0bef2?t=1544640490000" style="width: 1000px; height: 500px;" /></p> <p> <img alt="Shanling M2s df-slide (gradual)" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr%40SE.png/4d9de537-483f-49d9-82a9-a8a1ec7740ed?t=1544640567000" style="width: 1000px; height: 500px;" /></p> <p> Df-slides are self-explanatory, additional detailes are here → <a href="http://soundexpert.org/portable-players-beta2#howtoreaddfslides">How to read df-slides</a>.</p> <p> Conclusions from the above df-slides:<br /> <br /> <strong>(1)</strong> Low and High Gain modes are almost identical, you will not hear any difference between them with 32 Ohm headphones. High Gain mode can be useful only for high impedance and/or low sensitivity headphones.</p> <p> <strong>(2)</strong> Sine 1kHz signal is reproduced with high (and the same) accuracy in all modes. The Difference level -85.8 dB is equivalent to THD+N 0.007% (non-weighting). This is the best Df value for Sine 1kHz signal among portable players we've tested so far.</p> <p> <strong>(3)</strong> In all modes Sine 12.5kHz signal is reproduced with substantially lower accuracy (Figure 3).</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td style="width: 50%; text-align: center;"> <img alt="Diffrogram of the 1kHz Sine signal reproduced by Shanling M2s player" src="http://soundexpert.org/documents/10179/1131562/tech03_02.wav%28192%29__ref_tech03_02.wav%2844%29__mono_400-81.4553-78.7449-71.6362.png/56cdf39c-4774-4e26-b7af-87d1926b830a?t=1544805978000" style="width: 300px; height: 396px;" /></td> <td> <strong>Figure 3</strong>: Diffrogram of the 1kHz Sine signal reproduced by Shanling M2s player (x4 zoom). The time window of Df calculations <strong>Tw = 400ms, median Df = -78.7dB</strong>. Vertical stripes of different color correspond to the portions of signal (400ms) that degraded higher during playback. Instability of clock generator and low quality oversampling are usual causes of such <em>periodic</em> degradation.</td> </tr> </tbody> </table> <p> </p> <p> If we repeat this measurement with the shorter time window (50ms) the issue almost disappears because the window is substantially shorter than the period of fluctuations (~1.5s).</p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td> <img alt="The diffrogram from Fig.1 but computed using shorter time window" src="http://soundexpert.org/documents/10179/1131562/tech03_02.wav%28192%29__ref_tech03_02.wav%2844%29__mono_50-85.9610-85.0046-69.8199.png/345b53a2-384d-402f-93af-26cade5b5069?t=1544641598000" style="width: 600px; height: 99px;" /></td> <td> <p style="margin-left: 40px;"> <strong>Figure 4</strong>: The diffrogram from Fig.1 computed using shorter time window. <strong>Tw = 50ms, median Df = -85.0 dB</strong>. The periodic degradation of the signal is almost not noticeable.</p> </td> </tr> </tbody> </table> <p> </p> <p> Such time inaccuracy may potentially cause the sound quality degradation - loss of clarity in high frequency range; may be to some non-significant extent, though. But ... majority of other portable players on the market including smartphones do not have such issue, why here?</p> <p> <strong>(4)</strong> In gradual lowpass filter mode (and Low Gain) :</p> <ul> <li> the music material is reproduced with the same overall difference level - the histogram is almost exactly the same as in steep lowpass filter mode</li> <li> one tech. signal (sine 12.5kHz) is reproduced with higher accuracy (0.3dB increase)</li> <li> one tech. signal (sine 1kHz) is not affected by the setting</li> <li> eight tech. signals are reproduced with lower accuracy (square, both triangles, MOD-SMPTE, both BS EN 50332-1, white noise, DFD; the latter looses 13.6dB)</li> </ul> <p> From the above we can safely conclude that</p> <ul> <li> the difference between steep and gradual settings is hardly noticeable by human ear</li> <li> in steep mode accuracy of reproduction increases for majority of signals, so steep mode should be preferred.</li> </ul> <p> In the end, the portable player Shanling M2s (with firmware 2.0 and 44/16 music material) provides roughly the same audio quality as Apple iPhones 4/5/6, not better. Unfortunately there is no possibility to repeat the tests with the latest firmware (3.50) as the player has been already returned to the owner. But the firmware change logs since v2.0 do not mention any improvements related to the issue <strong>(3)</strong>.<br /> <br /> Df-slides of all tested players can be easily compared with each other on the <a href="http://soundexpert.org/portable-players-beta2">Portable Players</a> page. The page also has simple overview of the measurement procedure and metric.</p> <p> </p> <h3> Appendix</h3> <p> </p> <p> <strong>1. Diffrograms of 35 tracks</strong> of <a href="http://soundexpert.org/test-signals#variety">the test set “Variety”</a> in three testing modes. They show level of waveform degradation of the musical signal divided into 400ms chunks (one pixel each). Median Df values of the tracks are indicated. Click a track to open in full size for quick comparison with similar tracks from another setting/device. For example last 8s of the track #34 (Darkside - (2013) Psychic - Paper Trails) has slightly different color for steep and gradual filter modes. Which means that in steep mode ("greener" color) this portion of the track is reproduced with higher accuracy. More about diffrograms → <a href="http://soundexpert.org/articles/-/blogs/visualization-of-distortion">Diffrogram: visualization of signal differences in audio research</a>.</p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: left;"> <strong>All-off</strong></caption> <tbody> <tr> <td style="text-align: center;"> <span style="font-size:8px;">1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">10</span></td> <td style="text-align: center;"> <span style="font-size:8px;">11</span></td> <td style="text-align: center;"> <span style="font-size:8px;">12</span></td> <td style="text-align: center;"> <span style="font-size:8px;">13</span></td> <td style="text-align: center;"> <span style="font-size:8px;">14</span></td> <td style="text-align: center;"> <span style="font-size:8px;">15</span></td> <td style="text-align: center;"> <span style="font-size:8px;">16</span></td> <td style="text-align: center;"> <span style="font-size:8px;">17</span></td> <td style="text-align: center;"> <span style="font-size:8px;">18</span></td> <td style="text-align: center;"> <span style="font-size:8px;">19</span></td> <td style="text-align: center;"> <span style="font-size:8px;">20</span></td> <td style="text-align: center;"> <span style="font-size:8px;">21</span></td> <td style="text-align: center;"> <span style="font-size:8px;">22</span></td> <td style="text-align: center;"> <span style="font-size:8px;">23</span></td> <td style="text-align: center;"> <span style="font-size:8px;">24</span></td> <td style="text-align: center;"> <span style="font-size:8px;">25</span></td> <td style="text-align: center;"> <span style="font-size:8px;">26</span></td> <td style="text-align: center;"> <span style="font-size:8px;">27</span></td> <td style="text-align: center;"> <span style="font-size:8px;">28</span></td> <td style="text-align: center;"> <span style="font-size:8px;">29</span></td> <td style="text-align: center;"> <span style="font-size:8px;">30</span></td> <td style="text-align: center;"> <span style="font-size:8px;">31</span></td> <td style="text-align: center;"> <span style="font-size:8px;">32</span></td> <td style="text-align: center;"> <span style="font-size:8px;">33</span></td> <td style="text-align: center;"> <span style="font-size:8px;">34</span></td> <td style="text-align: center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-01.wav(192)__ref1.wav(44)__mono_400-38.3020-28.5504-0.0842.png" onclick="window.open(this.href, 'ShanlingM2sVariety1', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 1" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-01.wav(192)__ref1.wav(44)__mono_400-38.3020-28.5504-0.0842.png" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-02.wav(192)__ref2.wav(44)__mono_400-39.7167-24.2704-6.7489.png" onclick="window.open(this.href, 'ShanlingM2sVariety2', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=851,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 2" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-02.wav%28192%29__ref2.wav%2844%29__mono_400-39.7167-24.2704-6.7489.png" style="width: 31px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-03.wav(192)__ref3.wav(44)__mono_400-31.5906-23.7553-7.7922.png" onclick="window.open(this.href, 'ShanlingM2sVariety3', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 3" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-03.wav%28192%29__ref3.wav%2844%29__mono_400-31.5906-23.7553-7.7922.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-04.wav(192)__ref4.wav(44)__mono_400-39.3549-31.4822-21.8249.png" onclick="window.open(this.href, 'ShanlingM2sVariety4', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 4" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-04.wav%28192%29__ref4.wav%2844%29__mono_400-39.3549-31.4822-21.8249.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-05.wav(192)__ref5.wav(44)__mono_400-43.3654-24.8884-8.8257.png" onclick="window.open(this.href, 'ShanlingM2sVariety5', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=848,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 5" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-05.wav%28192%29__ref5.wav%2844%29__mono_400-43.3654-24.8884-8.8257.png" style="width: 31px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-06.wav(192)__ref6.wav(44)__mono_400-39.6501-25.5798-17.7958.png" onclick="window.open(this.href, 'ShanlingM2sVariety6', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 6" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-06.wav%28192%29__ref6.wav%2844%29__mono_400-39.6501-25.5798-17.7958.png" style="width: 26px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-07.wav(192)__ref7.wav(44)__mono_400-41.4077-30.4579-20.9903.png" onclick="window.open(this.href, 'ShanlingM2sVariety7', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 7" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-07.wav%28192%29__ref7.wav%2844%29__mono_400-41.4077-30.4579-20.9903.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-08.wav(192)__ref8.wav(44)__mono_400-31.0085-24.4398-15.0029.png" onclick="window.open(this.href, 'ShanlingM2sVariety8', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 8" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-08.wav%28192%29__ref8.wav%2844%29__mono_400-31.0085-24.4398-15.0029.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-09.wav(192)__ref9.wav(44)__mono_400-39.7074-22.3312-19.3144.png" onclick="window.open(this.href, 'ShanlingM2sVariety9', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 9" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-09.wav%28192%29__ref9.wav%2844%29__mono_400-39.7074-22.3312-19.3144.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-10.wav(192)__ref10.wav(44)__mono_400-31.9196-22.4410-3.7035.png" onclick="window.open(this.href, 'ShanlingM2sVariety10', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 10" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-10.wav%28192%29__ref10.wav%2844%29__mono_400-31.9196-22.4410-3.7035.png" style="width: 31px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-11.wav(192)__ref11.wav(44)__mono_400-37.0238-28.3115-3.6847.png" onclick="window.open(this.href, 'ShanlingM2sVariety11', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 11" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-11.wav%28192%29__ref11.wav%2844%29__mono_400-37.0238-28.3115-3.6847.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-12.wav(192)__ref12.wav(44)__mono_400-34.4708-23.6867-15.7110.png" onclick="window.open(this.href, 'ShanlingM2sVariety12', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=586,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 12" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-12.wav%28192%29__ref12.wav%2844%29__mono_400-34.4708-23.6867-15.7110.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-13.wav(192)__ref13.wav(44)__mono_400-38.3382-26.4643-15.7671.png" onclick="window.open(this.href, 'ShanlingM2sVariety13', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=655,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 13" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-13.wav%28192%29__ref13.wav%2844%29__mono_400-38.3382-26.4643-15.7671.png" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-14.wav(192)__ref14.wav(44)__mono_400-39.1088-26.0900-12.7094.png" onclick="window.open(this.href, 'ShanlingM2sVariety14', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=289,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 14" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-14.wav%28192%29__ref14.wav%2844%29__mono_400-39.1088-26.0900-12.7094.png" style="width: 25px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-15.wav(192)__ref15.wav(44)__mono_400-41.7871-33.6415-5.6545.png" onclick="window.open(this.href, 'ShanlingM2sVariety15', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=483,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 15" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-15.wav%28192%29__ref15.wav%2844%29__mono_400-41.7871-33.6415-5.6545.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-16.wav(192)__ref16.wav(44)__mono_400-37.0127-26.0939-5.0956.png" onclick="window.open(this.href, 'ShanlingM2sVariety16', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 16" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-16.wav%28192%29__ref16.wav%2844%29__mono_400-37.0127-26.0939-5.0956.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-17.wav(192)__ref17.wav(44)__mono_400-40.1376-32.3716-3.6400.png" onclick="window.open(this.href, 'ShanlingM2sVariety17', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 17" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-17.wav%28192%29__ref17.wav%2844%29__mono_400-40.1376-32.3716-3.6400.png" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-18.wav(192)__ref18.wav(44)__mono_400-33.6448-24.5808-17.1127.png" onclick="window.open(this.href, 'ShanlingM2sVariety18', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=680,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 18" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-18.wav%28192%29__ref18.wav%2844%29__mono_400-33.6448-24.5808-17.1127.png" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-19.wav(192)__ref19.wav(44)__mono_400-42.0021-31.5864-12.8311.png" onclick="window.open(this.href, 'ShanlingM2sVariety19', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=401,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 19" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-19.wav%28192%29__ref19.wav%2844%29__mono_400-42.0021-31.5864-12.8311.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-20.wav(192)__ref20.wav(44)__mono_400-55.3095-37.0160-15.8098.png" onclick="window.open(this.href, 'ShanlingM2sVariety20', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 20" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-20.wav%28192%29__ref20.wav%2844%29__mono_400-55.3095-37.0160-15.8098.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-21.wav(192)__ref21.wav(44)__mono_400-37.1743-29.9554-5.5951.png" onclick="window.open(this.href, 'ShanlingM2sVariety21', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 21" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-21.wav%28192%29__ref21.wav%2844%29__mono_400-37.1743-29.9554-5.5951.png" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-22.wav(192)__ref22.wav(44)__mono_400-34.4792-22.3305-15.6551.png" onclick="window.open(this.href, 'ShanlingM2sVariety22', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 22" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-22.wav%28192%29__ref22.wav%2844%29__mono_400-34.4792-22.3305-15.6551.png" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-23.wav(192)__ref23.wav(44)__mono_400-33.2406-25.5743-22.4833.png" onclick="window.open(this.href, 'ShanlingM2sVariety23', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 23" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-23.wav%28192%29__ref23.wav%2844%29__mono_400-33.2406-25.5743-22.4833.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-24.wav(192)__ref24.wav(44)__mono_400-30.8222-19.7210-17.5934.png" onclick="window.open(this.href, 'ShanlingM2sVariety24', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 24" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-24.wav%28192%29__ref24.wav%2844%29__mono_400-30.8222-19.7210-17.5934.png" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-25.wav(192)__ref25.wav(44)__mono_400-35.4072-26.4758-17.9607.png" onclick="window.open(this.href, 'ShanlingM2sVariety25', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 25" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-25.wav%28192%29__ref25.wav%2844%29__mono_400-35.4072-26.4758-17.9607.png" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-26.wav(192)__ref26.wav(44)__mono_400-43.3778-25.1702-17.0610.png" onclick="window.open(this.href, 'ShanlingM2sVariety26', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 26" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-26.wav%28192%29__ref26.wav%2844%29__mono_400-43.3778-25.1702-17.0610.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-27.wav(192)__ref27.wav(44)__mono_400-47.3869-22.2391-2.2820.png" onclick="window.open(this.href, 'ShanlingM2sVariety27', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 27" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-27.wav%28192%29__ref27.wav%2844%29__mono_400-47.3869-22.2391-2.2820.png" style="width: 30px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-28.wav(192)__ref28.wav(44)__mono_400-47.5627-18.9612-13.4241.png" onclick="window.open(this.href, 'ShanlingM2sVariety28', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 28" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-28.wav%28192%29__ref28.wav%2844%29__mono_400-47.5627-18.9612-13.4241.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-29.wav(192)__ref29.wav(44)__mono_400-31.9172-24.8799-18.6334.png" onclick="window.open(this.href, 'ShanlingM2sVariety29', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 29" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-29.wav%28192%29__ref29.wav%2844%29__mono_400-31.9172-24.8799-18.6334.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-30.wav(192)__ref30.wav(44)__mono_400-37.2495-25.1577-9.3312.png" onclick="window.open(this.href, 'ShanlingM2sVariety30', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 30" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-30.wav%28192%29__ref30.wav%2844%29__mono_400-37.2495-25.1577-9.3312.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-31.wav(192)__ref31.wav(44)__mono_400-35.8173-24.8823-14.3472.png" onclick="window.open(this.href, 'ShanlingM2sVariety31', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 31" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-31.wav%28192%29__ref31.wav%2844%29__mono_400-35.8173-24.8823-14.3472.png" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-32.wav(192)__ref32.wav(44)__mono_400-39.1255-19.1431-10.6707.png" onclick="window.open(this.href, 'ShanlingM2sVariety32', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 32" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-32.wav%28192%29__ref32.wav%2844%29__mono_400-39.1255-19.1431-10.6707.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-33.wav(192)__ref33.wav(44)__mono_400-40.0020-32.3854-11.2983.png" onclick="window.open(this.href, 'ShanlingM2sVariety33', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 33" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-33.wav%28192%29__ref33.wav%2844%29__mono_400-40.0020-32.3854-11.2983.png" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-34.wav(192)__ref34.wav(44)__mono_400-51.1862-25.2903-18.6335.png" onclick="window.open(this.href, 'ShanlingM2sVariety34', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 34" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-34.wav%28192%29__ref34.wav%2844%29__mono_400-51.1862-25.2903-18.6335.png" style="width: 30px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-35.wav(192)__ref35.wav(44)__mono_400-43.2259-27.8284-23.8919.png" onclick="window.open(this.href, 'ShanlingM2sVariety35', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109'); return false;"><img alt="Shanling Ms2 - Variety - 35" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-35.wav%28192%29__ref35.wav%2844%29__mono_400-43.2259-27.8284-23.8919.png" style="width: 25px; height: 99px;" /></a></td> </tr> <tr> <td style="text-align: center;"> <span style="font-size:8px;">-28.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-30.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-28.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-33.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-37.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-30.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.8</span></td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: left;"> <strong>HighGain</strong></caption> <tbody> <tr> <td style="text-align: center;"> <span style="font-size:8px;">1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">10</span></td> <td style="text-align: center;"> <span style="font-size:8px;">11</span></td> <td style="text-align: center;"> <span style="font-size:8px;">12</span></td> <td style="text-align: center;"> <span style="font-size:8px;">13</span></td> <td style="text-align: center;"> <span style="font-size:8px;">14</span></td> <td style="text-align: center;"> <span style="font-size:8px;">15</span></td> <td style="text-align: center;"> <span style="font-size:8px;">16</span></td> <td style="text-align: center;"> <span style="font-size:8px;">17</span></td> <td style="text-align: center;"> <span style="font-size:8px;">18</span></td> <td style="text-align: center;"> <span style="font-size:8px;">19</span></td> <td style="text-align: center;"> <span style="font-size:8px;">20</span></td> <td style="text-align: center;"> <span style="font-size:8px;">21</span></td> <td style="text-align: center;"> <span style="font-size:8px;">22</span></td> <td style="text-align: center;"> <span style="font-size:8px;">23</span></td> <td style="text-align: center;"> <span style="font-size:8px;">24</span></td> <td style="text-align: center;"> <span style="font-size:8px;">25</span></td> <td style="text-align: center;"> <span style="font-size:8px;">26</span></td> <td style="text-align: center;"> <span style="font-size:8px;">27</span></td> <td style="text-align: center;"> <span style="font-size:8px;">28</span></td> <td style="text-align: center;"> <span style="font-size:8px;">29</span></td> <td style="text-align: center;"> <span style="font-size:8px;">30</span></td> <td style="text-align: center;"> <span style="font-size:8px;">31</span></td> <td style="text-align: center;"> <span style="font-size:8px;">32</span></td> <td style="text-align: center;"> <span style="font-size:8px;">33</span></td> <td style="text-align: center;"> <span style="font-size:8px;">34</span></td> <td style="text-align: center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-01.wav(192)__ref1.wav(44)__mono_400-38.2034-28.4494-0.1542.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109'); return false;"><img 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'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 3" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-03.wav%28192%29__ref3.wav%2844%29__mono_400-31.5134-23.6903-7.7949.png" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-04.wav(192)__ref4.wav(44)__mono_400-39.2672-31.3952-21.7533.png" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 4" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-04.wav%28192%29__ref4.wav%2844%29__mono_400-39.2672-31.3952-21.7533.png" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a 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href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-16.wav(192)__ref16.wav(44)__mono_400-36.9548-26.0253-4.7813.png/b359195a-7c3d-4f4f-944e-23783c103046?t=1544724149000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 16" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-16.wav%28192%29__ref16.wav%2844%29__mono_400-36.9548-26.0253-4.7813.png/b359195a-7c3d-4f4f-944e-23783c103046?t=1544724149000" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-17.wav(192)__ref17.wav(44)__mono_400-40.0718-32.3302-3.7296.png/a93f7a15-d6fc-48e0-91da-a934f1336c58?t=1544724149000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 17" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-17.wav%28192%29__ref17.wav%2844%29__mono_400-40.0718-32.3302-3.7296.png/a93f7a15-d6fc-48e0-91da-a934f1336c58?t=1544724149000" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-18.wav(192)__ref18.wav(44)__mono_400-33.5797-24.5081-16.8948.png/d352c192-1df7-439c-8ac8-bda848e1c6da?t=1544724149000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=680,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 18" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-18.wav%28192%29__ref18.wav%2844%29__mono_400-33.5797-24.5081-16.8948.png/d352c192-1df7-439c-8ac8-bda848e1c6da?t=1544724149000" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-19.wav(192)__ref19.wav(44)__mono_400-41.9297-31.5219-12.8207.png/360fdbed-c9e3-4070-873f-9342a7d79e8a?t=1544724150000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=401,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 19" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-19.wav%28192%29__ref19.wav%2844%29__mono_400-41.9297-31.5219-12.8207.png/360fdbed-c9e3-4070-873f-9342a7d79e8a?t=1544724150000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-20.wav(192)__ref20.wav(44)__mono_400-55.1344-36.8671-15.5698.png/66594910-4de8-4453-a5fa-af67f5a7c717?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 20" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-20.wav%28192%29__ref20.wav%2844%29__mono_400-55.1344-36.8671-15.5698.png/66594910-4de8-4453-a5fa-af67f5a7c717?t=1544724151000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-21.wav(192)__ref21.wav(44)__mono_400-37.0392-29.8391-5.5443.png/d5a95284-fe37-49e3-805c-2ccf6bdbe263?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 21" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-21.wav%28192%29__ref21.wav%2844%29__mono_400-37.0392-29.8391-5.5443.png/d5a95284-fe37-49e3-805c-2ccf6bdbe263?t=1544724151000" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-22.wav(192)__ref22.wav(44)__mono_400-34.3599-22.1992-15.8499.png/d010155f-cad7-45c0-b5b2-13eaa1f6da78?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 22" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-22.wav%28192%29__ref22.wav%2844%29__mono_400-34.3599-22.1992-15.8499.png/d010155f-cad7-45c0-b5b2-13eaa1f6da78?t=1544724151000" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-23.wav(192)__ref23.wav(44)__mono_400-33.1314-25.4800-22.3656.png/4d0cc74d-9059-4f72-bbb4-0167d32449b2?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 23" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-23.wav%28192%29__ref23.wav%2844%29__mono_400-33.1314-25.4800-22.3656.png/4d0cc74d-9059-4f72-bbb4-0167d32449b2?t=1544724151000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-24.wav(192)__ref24.wav(44)__mono_400-30.7180-19.6125-17.4821.png/23bd7a8b-bb69-403d-9307-9e60e72d3428?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 24" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-24.wav%28192%29__ref24.wav%2844%29__mono_400-30.7180-19.6125-17.4821.png/23bd7a8b-bb69-403d-9307-9e60e72d3428?t=1544724151000" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-25.wav(192)__ref25.wav(44)__mono_400-35.3116-26.3732-17.8644.png/b6048c07-1415-40f4-afb4-748c43c62ee0?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 25" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-25.wav%28192%29__ref25.wav%2844%29__mono_400-35.3116-26.3732-17.8644.png/b6048c07-1415-40f4-afb4-748c43c62ee0?t=1544724151000" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-26.wav(192)__ref26.wav(44)__mono_400-43.2773-25.0775-16.8983.png/b844c823-2738-49db-b794-6293f1629853?t=1544724151000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 26" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-26.wav%28192%29__ref26.wav%2844%29__mono_400-43.2773-25.0775-16.8983.png/b844c823-2738-49db-b794-6293f1629853?t=1544724151000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-27.wav(192)__ref27.wav(44)__mono_400-47.3052-22.1471-2.7753.png/915398b2-927b-4278-acb1-5811ba8c2de2?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 27" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-27.wav%28192%29__ref27.wav%2844%29__mono_400-47.3052-22.1471-2.7753.png/915398b2-927b-4278-acb1-5811ba8c2de2?t=1544724152000" style="width: 30px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-28.wav(192)__ref28.wav(44)__mono_400-47.4921-18.8790-13.5188.png/8df004b1-6cbd-40d2-91f1-f188f566d5b9?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 28" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-28.wav%28192%29__ref28.wav%2844%29__mono_400-47.4921-18.8790-13.5188.png/8df004b1-6cbd-40d2-91f1-f188f566d5b9?t=1544724152000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-29.wav(192)__ref29.wav(44)__mono_400-31.8388-24.8009-18.5542.png/bb921f6d-1d69-4a1a-a7c0-da4e440147f8?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 29" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-29.wav%28192%29__ref29.wav%2844%29__mono_400-31.8388-24.8009-18.5542.png/bb921f6d-1d69-4a1a-a7c0-da4e440147f8?t=1544724152000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-30.wav(192)__ref30.wav(44)__mono_400-37.1831-25.0865-9.2694.png/476836d1-45e2-4267-b90d-07e2da20be10?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 30" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-30.wav%28192%29__ref30.wav%2844%29__mono_400-37.1831-25.0865-9.2694.png/476836d1-45e2-4267-b90d-07e2da20be10?t=1544724152000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-31.wav(192)__ref31.wav(44)__mono_400-35.7216-24.8092-14.2009.png/b79dd32d-b711-4e97-91c3-49eba5726626?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 31" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-31.wav%28192%29__ref31.wav%2844%29__mono_400-35.7216-24.8092-14.2009.png/b79dd32d-b711-4e97-91c3-49eba5726626?t=1544724152000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-32.wav(192)__ref32.wav(44)__mono_400-39.0376-19.0874-10.6955.png/80344667-68fc-4a3d-bb1d-1661e76b57a4?t=1544724152000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 32" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-32.wav%28192%29__ref32.wav%2844%29__mono_400-39.0376-19.0874-10.6955.png/80344667-68fc-4a3d-bb1d-1661e76b57a4?t=1544724152000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-33.wav(192)__ref33.wav(44)__mono_400-39.9062-32.3220-11.3287.png/13f0f450-1688-4524-abed-4600eff23bcf?t=1544724154000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 33" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-33.wav%28192%29__ref33.wav%2844%29__mono_400-39.9062-32.3220-11.3287.png/13f0f450-1688-4524-abed-4600eff23bcf?t=1544724154000" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-34.wav(192)__ref34.wav(44)__mono_400-51.1198-25.2244-18.5671.png/077463f7-de71-45ab-ba2a-b8d53da8a465?t=1544724154000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 34" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-34.wav%28192%29__ref34.wav%2844%29__mono_400-51.1198-25.2244-18.5671.png/077463f7-de71-45ab-ba2a-b8d53da8a465?t=1544724154000" style="width: 30px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-35.wav(192)__ref35.wav(44)__mono_400-43.1668-27.7647-24.0162.png/97dcbe7a-b229-46a9-9179-11a69ba5a006?t=1544724155000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109'); return false;"><img alt="Shanling Ms2(HG) - Variety - 35" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-HG-35.wav%28192%29__ref35.wav%2844%29__mono_400-43.1668-27.7647-24.0162.png/97dcbe7a-b229-46a9-9179-11a69ba5a006?t=1544724155000" style="width: 25px; height: 99px;" /></a></td> </tr> <tr> <td style="text-align: center;"> <span style="font-size:8px;">-28.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-30.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-28.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-33.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-36.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-29.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-18.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.8</span></td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <caption style="text-align: left;"> <strong>gradual</strong></caption> <tbody> <tr> <td style="text-align: center;"> <span style="font-size:8px;">1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">10</span></td> <td style="text-align: center;"> <span style="font-size:8px;">11</span></td> <td style="text-align: center;"> <span style="font-size:8px;">12</span></td> <td style="text-align: center;"> <span style="font-size:8px;">13</span></td> <td style="text-align: center;"> <span style="font-size:8px;">14</span></td> <td style="text-align: center;"> <span style="font-size:8px;">15</span></td> <td style="text-align: center;"> <span style="font-size:8px;">16</span></td> <td style="text-align: center;"> <span style="font-size:8px;">17</span></td> <td style="text-align: center;"> <span style="font-size:8px;">18</span></td> <td style="text-align: center;"> <span style="font-size:8px;">19</span></td> <td style="text-align: center;"> <span style="font-size:8px;">20</span></td> <td style="text-align: center;"> <span style="font-size:8px;">21</span></td> <td style="text-align: center;"> <span style="font-size:8px;">22</span></td> <td style="text-align: center;"> <span style="font-size:8px;">23</span></td> <td style="text-align: center;"> <span style="font-size:8px;">24</span></td> <td style="text-align: center;"> <span style="font-size:8px;">25</span></td> <td style="text-align: center;"> <span style="font-size:8px;">26</span></td> <td style="text-align: center;"> <span style="font-size:8px;">27</span></td> <td style="text-align: center;"> <span style="font-size:8px;">28</span></td> <td style="text-align: center;"> <span style="font-size:8px;">29</span></td> <td style="text-align: center;"> <span style="font-size:8px;">30</span></td> <td style="text-align: center;"> <span style="font-size:8px;">31</span></td> <td style="text-align: center;"> <span style="font-size:8px;">32</span></td> <td style="text-align: center;"> <span style="font-size:8px;">33</span></td> <td style="text-align: center;"> <span style="font-size:8px;">34</span></td> <td style="text-align: center;"> <span style="font-size:8px;">35</span></td> </tr> <tr> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-01.wav(192)__ref1.wav(44)__mono_400-38.1973-28.4531-0.1518.png/453bff60-f047-44f4-b18f-e2e86750c6d3?t=1544734885000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=659,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 1" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-01.wav%28192%29__ref1.wav%2844%29__mono_400-38.1973-28.4531-0.1518.png/453bff60-f047-44f4-b18f-e2e86750c6d3?t=1544734885000" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-02.wav(192)__ref2.wav(44)__mono_400-39.0902-24.1699-5.8508.png/0849cccf-ba3c-4653-83a4-c422f21e9889?t=1544734885000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=851,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 2" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-02.wav%28192%29__ref2.wav%2844%29__mono_400-39.0902-24.1699-5.8508.png/0849cccf-ba3c-4653-83a4-c422f21e9889?t=1544734885000" style="width: 31px; margin-left: 1px; margin-right: 1px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-03.wav(192)__ref3.wav(44)__mono_400-31.3797-23.6902-6.9374.png/e6ba9545-77fb-44a4-a43d-3901afa526c5?t=1544734885000/documents/10179/1131562/ShanlingM2s-gr-03.wav(192)__ref3.wav(44)__mono_400-31.3797-23.6902-6.9374.png/e6ba9545-77fb-44a4-a43d-3901afa526c5?t=1544734885000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=548,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 3" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-03.wav%28192%29__ref3.wav%2844%29__mono_400-31.3797-23.6902-6.9374.png/e6ba9545-77fb-44a4-a43d-3901afa526c5?t=1544734885000" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-04.wav(192)__ref4.wav(44)__mono_400-39.2739-31.4022-21.7617.png/bd9dc4a3-b9ae-48e0-83ae-e3cb0258b824?t=1544734885000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=506,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 4" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-04.wav%28192%29__ref4.wav%2844%29__mono_400-39.2739-31.4022-21.7617.png/bd9dc4a3-b9ae-48e0-83ae-e3cb0258b824?t=1544734885000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-05.wav(192)__ref5.wav(44)__mono_400-43.2215-24.7971-11.7158.png/3d838e77-cbf6-42aa-ac17-79b28e7f7825?t=1544734885000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=848,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 5" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-05.wav%28192%29__ref5.wav%2844%29__mono_400-43.2215-24.7971-11.7158.png/3d838e77-cbf6-42aa-ac17-79b28e7f7825?t=1544734885000" style="width: 31px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-06.wav(192)__ref6.wav(44)__mono_400-39.5343-25.4921-17.3935.png/7d1511df-3c51-4ccb-9a4e-a423bfea6560?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=378,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 6" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-06.wav%28192%29__ref6.wav%2844%29__mono_400-39.5343-25.4921-17.3935.png/7d1511df-3c51-4ccb-9a4e-a423bfea6560?t=1544734886000" style="width: 26px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-07.wav(192)__ref7.wav(44)__mono_400-41.3274-30.3763-20.9869.png/13e2f14e-4e52-4cdd-a64c-220499146b20?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=490,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 7" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-07.wav%28192%29__ref7.wav%2844%29__mono_400-41.3274-30.3763-20.9869.png/13e2f14e-4e52-4cdd-a64c-220499146b20?t=1544734886000" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-08.wav(192)__ref8.wav(44)__mono_400-30.7426-24.3081-14.8266.png/738dba1d-815b-4de6-9092-d63365234422?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=503,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 8" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-08.wav%28192%29__ref8.wav%2844%29__mono_400-30.7426-24.3081-14.8266.png/738dba1d-815b-4de6-9092-d63365234422?t=1544734886000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-09.wav(192)__ref9.wav(44)__mono_400-39.5277-22.2565-19.2378.png/d4796284-dc06-46cb-80d7-7e9e48957c63?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 9" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-09.wav%28192%29__ref9.wav%2844%29__mono_400-39.5277-22.2565-19.2378.png/d4796284-dc06-46cb-80d7-7e9e48957c63?t=1544734886000" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-10.wav(192)__ref10.wav(44)__mono_400-31.8608-22.3613-3.3281.png/1e47378e-0b86-4e04-8fd1-69b8b2ee89da?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=897,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 10" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-10.wav%28192%29__ref10.wav%2844%29__mono_400-31.8608-22.3613-3.3281.png/1e47378e-0b86-4e04-8fd1-69b8b2ee89da?t=1544734886000" style="width: 31px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-11.wav(192)__ref11.wav(44)__mono_400-36.9574-28.1903-3.5684.png/3bf45463-90fd-46be-a26c-d19221459bde?t=1544734886000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=604,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 11" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-11.wav%28192%29__ref11.wav%2844%29__mono_400-36.9574-28.1903-3.5684.png/3bf45463-90fd-46be-a26c-d19221459bde?t=1544734886000" style="width: 28px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-12.wav(192)__ref12.wav(44)__mono_400-34.4224-23.4898-14.5551.png/13d59a8c-ffbb-484b-bed7-fbc21265ebbf?t=1544734887000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=586,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 12" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-12.wav%28192%29__ref12.wav%2844%29__mono_400-34.4224-23.4898-14.5551.png/13d59a8c-ffbb-484b-bed7-fbc21265ebbf?t=1544734887000" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-13.wav(192)__ref13.wav(44)__mono_400-37.2415-26.1054-15.8636.png/362dec32-fbe4-4332-8ccc-27175597e9c8?t=1544734888000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=655,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 13" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-13.wav%28192%29__ref13.wav%2844%29__mono_400-37.2415-26.1054-15.8636.png/362dec32-fbe4-4332-8ccc-27175597e9c8?t=1544734888000" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-14.wav(192)__ref14.wav(44)__mono_400-39.0559-26.0216-11.8510.png/495edfac-62ac-4530-abdc-733767571f95?t=1544734888000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=289,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 14" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-14.wav%28192%29__ref14.wav%2844%29__mono_400-39.0559-26.0216-11.8510.png/495edfac-62ac-4530-abdc-733767571f95?t=1544734888000" style="width: 25px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-15.wav(192)__ref15.wav(44)__mono_400-41.7588-33.5930-4.2626.png/746703e2-6667-44fa-a763-cbbf89e5425f?t=1544734888000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=483,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 15" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-15.wav%28192%29__ref15.wav%2844%29__mono_400-41.7588-33.5930-4.2626.png/746703e2-6667-44fa-a763-cbbf89e5425f?t=1544734888000" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-16.wav(192)__ref16.wav(44)__mono_400-36.4622-25.8713-4.5739.png/f9038375-5137-496d-944f-2430535c1eb3?t=1544734888000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=552,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 16" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-16.wav%28192%29__ref16.wav%2844%29__mono_400-36.4622-25.8713-4.5739.png/f9038375-5137-496d-944f-2430535c1eb3?t=1544734888000" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-17.wav(192)__ref17.wav(44)__mono_400-40.0055-32.1587-3.6403.png/86f4502f-5feb-4eea-a2cb-fb345ca073df?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=332,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 17" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-17.wav%28192%29__ref17.wav%2844%29__mono_400-40.0055-32.1587-3.6403.png/86f4502f-5feb-4eea-a2cb-fb345ca073df?t=1544734889000" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-18.wav(192)__ref18.wav(44)__mono_400-33.3256-24.5002-15.6210.png/196afc3b-d893-4929-8834-4bf3d807111e?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=680,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 18" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-18.wav%28192%29__ref18.wav%2844%29__mono_400-33.3256-24.5002-15.6210.png/196afc3b-d893-4929-8834-4bf3d807111e?t=1544734889000" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-19.wav(192)__ref19.wav(44)__mono_400-41.9279-31.5200-13.7228.png/acaed0b6-9b83-4ca1-9aac-747faab3a267?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=401,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 19" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-19.wav%28192%29__ref19.wav%2844%29__mono_400-41.9279-31.5200-13.7228.png/acaed0b6-9b83-4ca1-9aac-747faab3a267?t=1544734889000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-20.wav(192)__ref20.wav(44)__mono_400-55.1579-36.9411-14.8081.png/3857141e-8c75-4625-849c-595faab65b03?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=452,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 20" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-20.wav%28192%29__ref20.wav%2844%29__mono_400-55.1579-36.9411-14.8081.png/3857141e-8c75-4625-849c-595faab65b03?t=1544734889000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-21.wav(192)__ref21.wav(44)__mono_400-37.0930-29.8767-5.5743.png/3b0cf8ce-25a7-4a83-a54d-5ba9aef147ab?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=525,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 21" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-21.wav%28192%29__ref21.wav%2844%29__mono_400-37.0930-29.8767-5.5743.png/3b0cf8ce-25a7-4a83-a54d-5ba9aef147ab?t=1544734889000" style="width: 27px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-22.wav(192)__ref22.wav(44)__mono_400-33.3036-22.2438-15.5529.png/d7ea2367-b777-4694-a6cb-bfbfc1a10f0f?t=1544734889000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=537,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 22" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-22.wav%28192%29__ref22.wav%2844%29__mono_400-33.3036-22.2438-15.5529.png/d7ea2367-b777-4694-a6cb-bfbfc1a10f0f?t=1544734889000" style="width: 28px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-23.wav(192)__ref23.wav(44)__mono_400-33.2013-25.4570-22.3660.png/37eda0de-57a5-423e-8aa0-88c35a09e2ee?t=1544734890000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=430,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 23" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-23.wav%28192%29__ref23.wav%2844%29__mono_400-33.2013-25.4570-22.3660.png/37eda0de-57a5-423e-8aa0-88c35a09e2ee?t=1544734890000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-24.wav(192)__ref24.wav(44)__mono_400-30.7291-19.6480-17.5152.png/103dad45-6ca1-4516-ad2b-a9768843e1ee?t=1544734890000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=641,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 24" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-24.wav%28192%29__ref24.wav%2844%29__mono_400-30.7291-19.6480-17.5152.png/103dad45-6ca1-4516-ad2b-a9768843e1ee?t=1544734890000" style="width: 29px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-25.wav(192)__ref25.wav(44)__mono_400-35.3268-26.3843-17.8805.png/2f25ca33-02eb-40f3-8cc3-bba00601912f?t=1544734890000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=671,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 25" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-25.wav%28192%29__ref25.wav%2844%29__mono_400-35.3268-26.3843-17.8805.png/2f25ca33-02eb-40f3-8cc3-bba00601912f?t=1544734890000" style="width: 29px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-26.wav(192)__ref26.wav(44)__mono_400-43.2881-25.0971-16.0962.png/1e6cdb69-70ef-4a5c-9873-ae2095b360b9?t=1544734890000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=522,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 26" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-26.wav%28192%29__ref26.wav%2844%29__mono_400-43.2881-25.0971-16.0962.png/1e6cdb69-70ef-4a5c-9873-ae2095b360b9?t=1544734890000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-27.wav(192)__ref27.wav(44)__mono_400-47.3181-22.1687-2.3065.png/8d5a2fe7-9916-411f-b6c8-d10027b6c565?t=1544734891000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=730,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 27" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-27.wav%28192%29__ref27.wav%2844%29__mono_400-47.3181-22.1687-2.3065.png/8d5a2fe7-9916-411f-b6c8-d10027b6c565?t=1544734891000" style="width: 30px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-28.wav(192)__ref28.wav(44)__mono_400-47.4701-18.8967-13.0963.png/3b2ec488-a8fd-440e-936a-17ca188b9574?t=1544734892000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=510,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 28" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-28.wav%28192%29__ref28.wav%2844%29__mono_400-47.4701-18.8967-13.0963.png/3b2ec488-a8fd-440e-936a-17ca188b9574?t=1544734892000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-29.wav(192)__ref29.wav(44)__mono_400-31.8487-24.8116-18.5918.png/bc59ea73-2dd3-45bc-b9bc-88b320d5f6d7?t=1544734892000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=429,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 29" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-29.wav%28192%29__ref29.wav%2844%29__mono_400-31.8487-24.8116-18.5918.png/bc59ea73-2dd3-45bc-b9bc-88b320d5f6d7?t=1544734892000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-30.wav(192)__ref30.wav(44)__mono_400-37.0561-25.0814-9.2618.png/41a2d558-c25e-47e0-8685-a51e06798239?t=1544734892000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=444,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 30" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-30.wav%28192%29__ref30.wav%2844%29__mono_400-37.0561-25.0814-9.2618.png/41a2d558-c25e-47e0-8685-a51e06798239?t=1544734892000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-31.wav(192)__ref31.wav(44)__mono_400-35.6936-24.8006-12.9217.png/72b158e2-5f2d-4964-b0a9-5afd215f746a?t=1544734893000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=353,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 31" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-31.wav%28192%29__ref31.wav%2844%29__mono_400-35.6936-24.8006-12.9217.png/72b158e2-5f2d-4964-b0a9-5afd215f746a?t=1544734893000" style="width: 26px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-32.wav(192)__ref32.wav(44)__mono_400-39.0513-19.0970-10.3210.png/a536b7a7-d114-4462-a30e-07bbd72957ca?t=1544734894000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=485,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 32" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-32.wav%28192%29__ref32.wav%2844%29__mono_400-39.0513-19.0970-10.3210.png/a536b7a7-d114-4462-a30e-07bbd72957ca?t=1544734894000" style="width: 27px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-33.wav(192)__ref33.wav(44)__mono_400-39.9230-32.3300-11.1345.png/100734be-aed0-46c4-bf91-97829795f712?t=1544734894000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=315,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 33" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-33.wav%28192%29__ref33.wav%2844%29__mono_400-39.9230-32.3300-11.1345.png/100734be-aed0-46c4-bf91-97829795f712?t=1544734894000" style="width: 25px; height: 99px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-34.wav(192)__ref34.wav(44)__mono_400-46.1032-24.9282-18.5776.png/7067244b-27b6-4a83-b29a-327e9a177f33?t=1544734894000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=734,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 34" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-34.wav%28192%29__ref34.wav%2844%29__mono_400-46.1032-24.9282-18.5776.png/7067244b-27b6-4a83-b29a-327e9a177f33?t=1544734894000" style="width: 30px; height: 99px; margin-left: 1px; margin-right: 1px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-35.wav(192)__ref35.wav(44)__mono_400-43.1291-27.7526-24.0119.png/507655bd-065f-429d-b8ee-37da170dd833?t=1544734894000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=337,height=109'); return false;"><img alt="Shanling Ms2(gr) - Variety - 35" src="http://soundexpert.org/documents/10179/1131562/ShanlingM2s-gr-35.wav%28192%29__ref35.wav%2844%29__mono_400-43.1291-27.7526-24.0119.png/507655bd-065f-429d-b8ee-37da170dd833?t=1544734894000" style="width: 25px; height: 99px;" /></a></td> </tr> <tr> <td style="text-align: center;"> <span style="font-size:8px;">-28.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.7</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-30.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-28.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-23.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.0</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-33.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-31.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-36.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-29.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.5</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.6</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-26.4</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-22.2</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-18.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-25.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.8</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-19.1</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-32.3</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-24.9</span></td> <td style="text-align: center;"> <span style="font-size:8px;">-27.8</span></td> </tr> </tbody> </table> <p> </p> <p> </p> <p> </p> <p> <strong>2. Dendrogram of similarity of artifact signatures</strong> for the portable players.</p> <table border="0" cellpadding="0" cellspacing="0" style="width:100%;"> <tbody> <tr> <td> <img alt="Dendrogram showing similarity of artifact signatures of tested players" src="http://soundexpert.org/documents/10179/1131562/dendro-portplayers-6.png/957ec4a4-eef8-4d4e-b0e7-7e0d3f1c8e03?t=1544642897000" style="width: 700px; height: 500px;" /></td> <td> <p style="margin-left: 40px;"> <strong>Figure 5</strong>: Dendrogram showing similarity of artifact signatures of tested players. The shorter the link between two players, the more similar their artifact signatures. The Spearman distance = 0.1 is critical for relation of Df measurements to subjective scores. For the players which have similar artifact signatures (distance < 0.1) their perceived sound quality estimations correlate well to df-measurements, computed with real-life music material (histogram medians).</p> </td> </tr> </tbody> </table> <p> </p>Serge Smirnoff2018-12-03T16:27:00ZCrowdfunding audio research with open and legit mining of cryptocurrency in browserSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/crowdfunding-audio-research-with-open-and-legit-mining-of-cryptocurrency-in-browser2019-03-17T06:29:58Z2018-11-13T09:19:00Z<p> Monetization of web content through cryptomining in browsers still has controversial status among web developers.</p> <p> <strong>Pros</strong></p> <ul> <li> clear and simple concept - a visitor pays as long as she uses web resource</li> <li> nothing distracts visitor's attention from web content, in other words, she pays with computing power of her device, not with her attention</li> <li> simple and secure payouts to site owners in cryptocurrency</li> </ul> <p> <strong>Cons</strong></p> <ul> <li> time spent on site is not always a good measure of content value</li> <li> possibility of using the technology without visitor's permission</li> <li> slowing down and accelerating deterioration of visitor's hardware</li> </ul> <p> After the well-known false start of Coinhive service at PirateBay where it was used without user consent, Coinhive developers offered the version of their JS miner which can't be used without visitor's permission. This move along with the negotiations with leading anti-virus and ad-blocking companies results in appearance of pure legit mining service, which can be used as a valid alternative to monetization with ads.</p> <p> Coinhive is not alone. According to the recent research from FORTH-ICS the market shares of main players look like follows:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="1" style="width:100%;"> <tbody> <tr> <td> <img alt="In-browser mining shares" src="http://soundexpert.org/documents/10179/1131562/fig1-crypto-market-share.png/f9a6b0b6-4c91-4605-9d8d-75e9a1f6d2e5?t=1542101090000" style="width: 547px; height: 376px;" /></td> <td style="padding-left: 20px;"> <strong>Figure 1</strong>: Cryptomining market share per third party library in our dataset. As seen, Coinhive owns the dominant share (69%) when JSEcoin follows with 13% [from <a href="https://arxiv.org/abs/1806.01994" target="_blank">Truth in Web Mining: Measuring the Profitability and Cost of Cryptominers as a Web Monetization Model</a>]</td> </tr> </tbody> </table> <p> </p> <p> </p> <p> From the research:</p> <p style="margin-left: 40px;"> <cite><em>To conclude, cryptomining indeed has the potential to become a reliable alternative for some content providers, but it is not capable of replacing the current ad-driven monetization model of the web.</em></cite></p> <p> The main reason for the conclusion is that the current mining-driven model is less profitable than ad-driven. But those content providers who can keep visitors on their web sites more than 5.3 minutes benefit from the new model. Music and video come to mind first. Porn industry? There is an assumption that VHS won over Betamax due to the pornographic movie market. It looks like the porn industry has the new challenge - mining vs. advertising.</p> <p> For other content providers the mining-driven model is less attractive, at least at the current state of its development. But it's not hard to imagine some open and decentralized web analysis/payment system, which will reward site owners according to actual site usage in the system's own coins. Web servers and visitors' browsers connected in p2p network could provide enough computing power for such system to work. This network will also provide web-analytics and - if openly and ethically designed - it will collect only anonymous info about visitors, so there would be no reason to avoid it.</p> <p> Today monetization with in-browser mining is on its early stage of adoption and mining for crowdfunding is even less explored area. Somebody has to try. For our fundraising campaign at SoundExpert (SE) we use incentivized mining with some small rewards. This scenario, described below, was developed according to peculiarity of SE project and its audience.</p> <p> SE was born with the idea that audio consumers must have their own service for sound quality assessments/measurements, the service that is independent from manufacturing side. And this is our main reason for being. Since 2001 SE maintains continuous distributed listening tests of audio codecs. Sound quality ratings of 100+ codecs are computed thanks to volunteers participating in the tests (more than 10 000 to date). During the last two years a new method of audio quality benchmarking for portable players was developed and tested. It uses innovative music-based audio measurements that correlate well to sound quality estimations made by humans. Such objective measurements for a tested device can be shown in one compact df-slide, which gives in-detail picture of audio performance at a glance (Fig.2).</p> <p> </p> <p> <img alt="Df-slide with audio measurements" src="http://soundexpert.org/documents/10179/296478/AppleiPadMini2%40SE.png/2e30e284-9e00-48a4-8b1f-2885ebcdd474?t=1540974461000" style="width: 1000px; height: 500px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 2</strong>: Df-slide with audio measurements. See <a href="http://soundexpert.org/portable-players#howtoreaddfslides" target="_blank">How to read df-slides</a> for details.</p> <p> </p> <p> Such df-slides of different devices can be easily compared with each other and sorted according to sound quality. Df-slides of 27 portable players computed during R&D period are published <a href="http://soundexpert.org/portable-players-beta" target="_blank">here</a><a href="http://soundexpert.org/portable-players-beta).">.</a> The research is still in progress but the sound quality benchmark, based on objective measurements, is already a reality. First two portable devices are in the collection of tested players.</p> <p> We are thankful to people who shared out their portable audio devices (30+) during the beta testing. Thanks to them we managed to develop the final reliable procedure of measurements. Unfortunately, it requires that a device under test has to be with us for a few days with possibility of changing its settings, firmware, operating system, etc. In other words we need those devices to be bought.</p> <p> As SE is made for-and-by audio consumers we launched crowdfunding campaign for purchasing popular portable audio players for testing. Already tested devices will be sold for the purpose of buying laboratory-grade measurement equipment, which in turn will allow testing wide range of audio devices, not only portable players.</p> <p> Our fundraising campaign uses both traditional donations through PayPal and mining of cryptocurrency in browser. Visitors can propose and mine for particular portable player, which will be bought and tested when its fundraising goal is achieved. Thus, every miner has a kind of helpful reward - results of highly revealing audio measurements for device of her interest.</p> <p> We designed our mining page in such a way that under no circumstances a visitor can start mining by chance or accidentally or because of inattentiveness. The mining can be started wittingly with full understanding of the goal only. This is what we call open and ethical in-browser mining. Coinhive authed miner perfectly fits the purpose. In addition it allows adjusting of comfortable payload, so a user has full control over the process. Progress bar of fundraising is updated every 10 minutes getting current state with Coinhive API, so a user has live info about the sum already mined.</p> <p> As it was already said, current in-browser mining is not very efficient/profitable. For example, rising of $100 with mining alone will require participation of 5000 - 7000 people who will leave their desktops/notebooks mining at nights during one week. The figures are a bit scary, to say the least. Anyway, our experimental crowdfunding campaign has started. To be honest we don't know how it will go. This is the price early adopters pay.</p> <p> If somebody can offer her lovely audio player for our extensive testing, we are still ready and thankful. Manufacturers are welcome on an equal basis. All devices will be returned after testing.</p> <p style="text-align: center;"> <strong><a href="http://soundexpert.org/mining">soundexpert.org/mining</a> ►</strong></p> <p> Your SE team.</p> <p> </p> <p> <strong>Update 2019-03-16</strong></p> <hr /> <p> Coinhive decided to discontinue its service on the 8th of March 2019. During three months of operation total ¢18 were mined by visitors of SE site. The epic fail )). Anyway, it was a helpful experience and $1 was added to each player visitors mined for, we love our contributors-miners, their efforts must not be in vain.</p> <p> The next attempt to survive will be with <a href="https://jsecoin.com/en/home" target="_blank">JSEcoin platform</a>, which rewards webmasters with cryptocurrency (JSE) for the time visitors spent on their sites. This platform utilizes a tiny amount of computing power of visitor's browser and only in case she explicitly opted-in. So when you first see the JSEcoin banner at the bottom of our site - don't be afraid to press "Continue", this will not affect your browsing experience. And we continue to strive for operation without loss. Your SE team.</p> <p> </p>Serge Smirnoff2018-11-13T09:19:00ZAudio quality of Bluetooth music receiver TS-BTAD01Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-bluetooth-music-receiver-ts-btad012018-08-30T12:43:18Z2017-07-11T13:46:00Z<p> Initially this device was planned to be used for aptX testing/research. Two guys responded to the call for donations in the article <a href="http://soundexpert.org/news/-/blogs/audio-quality-of-bluetooth-aptx">Audio quality of bluetooth aptX</a> and after some time Bluetooth Music Receiver TS-BTAD01 was delivered from DealeXtreme.</p> <p> </p> <p> <img alt="Bluetooth Music Receiver TS-BTAD01 package." src="http://soundexpert.org/documents/10179/832303/TS-BTAD01.jpg/cbd9194c-2922-40b1-a6de-4d3cfc8e07fb?t=1499803159000" style="width: 1000px; height: 666px;" /><br /> <strong> Figure 1</strong>. Bluetooth Music Receiver package contents.</p> <p> </p> <p> The plan was to use digital out of the receiver to record bit-perfect output of aptX decoder. Such recordings could be used for analysis/comparison of aptX and SBC codecs.<br /> <br /> Unfortunately the quality of output interfaces of the device both digital and analog is so extremely low that the mission is impossible. The main problem with its S/PDIF out is low quality resampling to 48 kHz using very unstable clock. Even more, according to the measurements below the signal is converted twice. First, decoded aptX/SBC stream is converted to analog and then converted to digital again @48kHz using low-cost IC solution. Needless to say that such processing distorts the signal much more than the codecs alone, making this device unusable for aptX research.<br /> <br /> Nevertheless, I performed standard SE objective measurements of the device using real-life music material and comparing input and output waveforms. Results are below.</p> <p> <br /> <br /> <img alt="Df measurements of Bluetooth music receiver TS-BTAD01 " src="http://soundexpert.org/documents/10179/832303/TS-BTAD01%40SoundExpert.png/f1ccc57e-50b3-433a-95cc-a60da8d6534c?t=1499803159000" style="width: 1000px; height: 1114px;" /><br /> <strong>Figure 2</strong>. Df measurements of TS-BTAD01 with real music material.</p> <p> <br /> As you can see the difference between aptX and SBC codecs (and three quality modes for the latter) is almost completely eliminated by the awkward design of output circuitry. Resulting sound is harsh and leads to listening fatigue in minutes. Exactly such Bluetooth devices make bad reputation for Bluetooth audio as a technology.<br /> <br /> Manufacturing of this audio crap is possible not least because usual THD+N measurements look good even for such devices. The enclosed leaflet for TS-BTAD01 proudly specifies THD = 0.05% (-66 dB). Indeed, if we look at Df measurements with pure Sine signal instead of real music signal we can see that the above THD value is quite correct. Even the difference between codecs and digital out is not so dramatic.<br /> </p> <table align="center" border="1"> <caption> <strong>Table 1</strong>. Df measurements of TS-BTAD01 with Sine signal<br /> (1kHz, -10dBFS, 30s, L=R). Df (dB) ≈ THD - 3 (dB)</caption> <tbody> <tr> <td style="text-align: center;"> </td> <td style="text-align: center;"> Codec alone</td> <td style="text-align: center;"> Digital out</td> <td style="text-align: center;"> Analog out</td> </tr> <tr> <td style="text-align: center;"> aptX@352 kbit/s</td> <td style="text-align: center;"> </td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-aptX@352kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-aptx_mono_400-70.3048-70.0185-68.0284.png/f4e75d93-b5b5-49d4-b9d7-7813bcecb298?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-aptX@352kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-aptx_mono_400-62.6279-61.9228-61.2973.png/054ebd19-5f46-4581-af39-e3ac6f00a4c7?t=1499803157000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@328 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40328_mono_400-72.2500-72.1980-72.1069.png/84c6eeb0-9b31-40c9-b5f9-9374bf1b2ea2?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40328_mono_400-70.9362-70.6110-70.2284.png/7c0b855a-9307-4ce4-8ea7-9af08624946c?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40328_mono_400-62.6167-61.9924-60.9034.png/7d827b0a-d931-4bbe-bbee-9746b27940be?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@229 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40229_mono_400-72.3577-72.3014-72.2614.png/65ec11dd-a315-4c5a-8489-51ddaf42ba5c?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40229_mono_400-71.2747-70.9653-70.4798.png/cc9a39eb-878e-4552-8bec-2b4008c6b9b7?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40229_mono_400-62.8052-61.6508-60.9928.png/50ad4c55-958a-45d6-b215-c5a6f6362458?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@201 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40201_mono_400-73.3064-73.2331-73.1888.png/09ca9936-5921-41ab-9624-202d34fab8e7?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40201_mono_400-71.6894-71.3877-70.6488.png/9fbd76d8-a37c-4f18-9a0c-2077a84d90ed?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40201_mono_400-62.6081-61.7056-60.0604.png/9c8573f9-4b9f-4875-8d48-d5d49c16b7b0?t=1499803158000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> </tbody> </table> <p> <br /> <br /> The problem with THD measurements is that degradation of pure Sine wave is always substantially less than of real music signal. In other words, an awfully sounding device can still have decent THD measurements.<br /> <br /> Anyway, Bluetooth Music Receiver TS-BTAD01</p> <ul> <li> has nice plastic case with blue LED and various outputs,</li> <li> easily pairs with any SBC/aptX Bluetooth devices,</li> <li> is worldwide available on-line for $30 (under various names and brands) and</li> <li> is suitable for playing quiet background music in your garden.</li> </ul> <p> There is no way to use it for attentive/critical listening.<br /> <br /> Thank you, Pierre and Alexey for your donations and sorry for not completing the mission – to compare SBC and aptX codecs. I will do this in some other way.</p> <p style="text-align: right;"> <strong>Update</strong></p> <hr /> <p style="text-align: right;"> 2018 August</p> <p> Starting from version 4.0 A/V processor ffmpeg has encoding/decoding capabilities for aptX and aptX HD formats. Both codecs have been added to SE blind testing engine. Results can be found on <a href="http://soundexpert.org/encoders-320-kbps">Encoders 320+ kbit/s</a> page. Technical details of these codecs performance are in the article - <a href="http://soundexpert.org/news/-/blogs/audio-quality-of-bluetooth-aptx">Audio quality of Bluetooth aptX and aptX HD</a>.</p> <p> Below are updated Figure 2 and Table 1. They were supplemented with objective measurements of aptX codec. This update doesn't change logic of the article and conclusions made.</p> <p> </p> <p> </p> <p> <img alt="Df measurements of Bluetooth music receiver TS-BTAD01 (updated)" src="http://soundexpert.org/documents/10179/1131562/TS-BTAD01%40SoundExpertV2.png/c0cdbf44-3d57-4092-b5cf-c2415026a85d?t=1534891747000" style="width: 1000px; height: 1220px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 2 (updated)</strong>. Histogram of aptX codec was added.</p> <p> </p> <table align="center" border="1"> <caption> <strong>Table 1 <strong>(updated)</strong></strong>. Diffrogram of aptX codec was added.</caption> <tbody> <tr> <td style="text-align: center;"> </td> <td style="text-align: center;"> Codec alone</td> <td style="text-align: center;"> Digital out</td> <td style="text-align: center;"> Analog out</td> </tr> <tr> <td style="text-align: center;"> aptX@352 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of aptX@352kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/1131562/btaptx%40352_mono_400-72.0055-71.7477-71.4924.png/ff7382fb-610a-43be-8145-236954b08985?t=1535020618000" style="width: 79px; height: 103px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-aptX@352kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-aptx_mono_400-70.3048-70.0185-68.0284.png/f4e75d93-b5b5-49d4-b9d7-7813bcecb298?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-aptX@352kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-aptx_mono_400-62.6279-61.9228-61.2973.png/054ebd19-5f46-4581-af39-e3ac6f00a4c7?t=1499803157000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@328 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40328_mono_400-72.2500-72.1980-72.1069.png/84c6eeb0-9b31-40c9-b5f9-9374bf1b2ea2?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40328_mono_400-70.9362-70.6110-70.2284.png/7c0b855a-9307-4ce4-8ea7-9af08624946c?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@328kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40328_mono_400-62.6167-61.9924-60.9034.png/7d827b0a-d931-4bbe-bbee-9746b27940be?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@229 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40229_mono_400-72.3577-72.3014-72.2614.png/65ec11dd-a315-4c5a-8489-51ddaf42ba5c?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40229_mono_400-71.2747-70.9653-70.4798.png/cc9a39eb-878e-4552-8bec-2b4008c6b9b7?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@229kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40229_mono_400-62.8052-61.6508-60.9928.png/50ad4c55-958a-45d6-b215-c5a6f6362458?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> <tr> <td style="text-align: center;"> SBC@201 kbit/s</td> <td style="text-align: center;"> <img alt="Df measurements of SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/sbc%40201_mono_400-73.3064-73.2331-73.1888.png/09ca9936-5921-41ab-9624-202d34fab8e7?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-d-SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-d-sbc%40201_mono_400-71.6894-71.3877-70.6488.png/9fbd76d8-a37c-4f18-9a0c-2077a84d90ed?t=1499803159000" style="width: 79px; height: 103px; margin: 20px;" /></td> <td style="text-align: center;"> <img alt="Df measurements of TS-BTAD01-a-SBC@201kbit/s with sine signal 1kHz" src="http://soundexpert.org/documents/10179/832303/btad01-a-sbc%40201_mono_400-62.6081-61.7056-60.0604.png/9c8573f9-4b9f-4875-8d48-d5d49c16b7b0?t=1499803158000" style="width: 79px; height: 103px; margin: 20px;" /></td> </tr> </tbody> </table> <p> </p>Serge Smirnoff2017-07-11T13:46:00ZObjective difference measurements to predict listening test results?Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/objective-difference-measurements-to-predict-listening-test-results-2018-09-24T21:57:35Z2015-11-02T07:05:00Z<h3> Abstract</h3> <p> Preliminary research at SoundExpert shows that there is high probability that relationship between waveform degradation of an audio material and its auditory perception does exist. This research is aimed to explore such relationship and its limitations. For the purpose several listening test cases (the more, the better) should be examined comparing levels of waveform degradation with subjective quality scores.</p> <p> If such dependency is proved then reliable audio quality assessment will become easier and cheaper by means of:</p> <ul> <li> <strong>More productive listening tests</strong>. A listening test conducted for several contenders could provide quality scores for many more contenders with foreknown accuracy. Also results of an already finished listening test could be reused many times by adding new contenders afterwards and computing their quality scores analytically.</li> <li> <strong>Objective measurements with high correlation to subjective scores</strong>. Such measurements, based on statistical difference testing, can be translated into quality scores directly and will be valid for both analog and digital domains.</li> </ul> <p> The research log below is updated live as the work goes on.</p> <p> </p> <h2> <span style="font-size:18px;"><strong>Case #1. Personal Listening Test of MP3/Opus/AAC at 96kbps by Kamedo2 (1 listener)</strong></span></h2> <p style="text-align: right;"> Draft. 2015 Nov 2. Research in progress ...</p> <p> </p> <p> Results of this test were published on Hydrogen Audio forum (<a href="https://www.hydrogenaud.io/forums/index.php?showtopic=109716" target="_blank">https://www.hydrogenaud.io/forums/index.php?showtopic=109716</a>). The test was performed by one listener – Kamedo2 - using 74 sound samples.</p> <p> Encoders:<br /> LAME 3.99.5<br /> Opus 1.1 with opus-tools-0.1.9, win32<br /> NeroAACEnc 1.5.4.0<br /> ffmpeg r.70351 with v7 patch applied<br /> ffmpeg r.70351 with v9b patch applied<br /> <br /> Settings:<br /> lame --abr 98 -S in.wav out.mp3<br /> opusenc --bitrate 91 in.wav out.opus<br /> NeroAacEnc -q 0.333 -if in.wav -of out.mp4<br /> ffmpeg70351_v7 -y -i in.wav -c:a aac -strict experimental -b:a 96k out.mp4<br /> ffmpeg70351_v9b -y -i in.wav -c:a aac -strict experimental -b:a 96k out.mp4<br /> <br /> Samples:<br /> Total 74 samples.<br /> 40 samples from <a href="http://listening-test.coresv.net/results.htm" target="_blank">2014 public listening test</a><br /> 25 samples from <a href="http://www.hydrogenaud.io/forums/index.php?showtopic=100896" target="_blank">Kamedo2 corpus</a><br /> 9 samples from <a href="http://soundexpert.org/sound-samples" target="_blank">SoundExpert</a><br /> <br /> Hardware:<br /> Sony PSP-3000 + RP-HJE150.<br /> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Results of Kamedo2 listening test" src="http://soundexpert.org/documents/10179/272881/15g2cxz.png/a83a0a1c-63f9-427e-8dbc-f4bb98d7c33b?t=1446449303000" style="width: 600px; height: 450px; float: left;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 1</strong>. Results of Kamedo2 listening test.</p> </td> </tr> </tbody> </table> <p> </p> <p> So, we have the following mean scores of perceived sound quality:</p> <pre> <span style="font-size:14px;">opus nero lame ffv9b ffv7 4.31 3.93 3.65 3.42 3.13</span></pre> <p> </p> <p> Thanks to Kamedo2 all sources – sound samples and codec versions – are also available and can be used for objective/instrumental research.</p> <h3> Measurements of waveform degradation</h3> <p> Difference between original and processed by codecs waveforms will be measured in dB of Difference level (Df) with diffrogram program from <a href="http://soundexpert.org/news/-/blogs/visualization-of-distortion#part3" target="_blank">here</a>. We will use piece-wise Df measurements with time window of 400ms (impact of this parameter could be further researched). Such measurements produce multiple Df values (3568 in our case) which preserve valuable information about nature of waveform degradation.</p> <p> Now we concatenate all 74 sound excerpts removing zero samples at the beginning and the end and applying 2.3ms cross-fade (100 samples) between excerpts. Thus we obtain a 1447s long (23:47) seamlessly mixed test vector containing sound material native to the Kamedo2 listening test. It is processed by all codecs with exact settings used in the listening test. As the decoded files have different sampling rates (32, 44.1, 48 kHz) they all are up-sampled to 96 kHz before Df calculations. Histograms of the resulting Df values for each codec are below:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> opus</td> <td> <img alt="Histogram of Opus Df values with native sound material" src="http://soundexpert.org/documents/10179/272881/kd2_opus.png/67093d4a-3af9-4371-a3a0-67f7b3f49d5b?t=1446447776000" style="width: 709px; height: 140px;" /></td> </tr> <tr> <td> nero</td> <td> <img alt="Histogram of Nero Df values with native sound material" src="http://soundexpert.org/documents/10179/272881/kd2_nero.png/6f7eec33-1506-4246-80e9-58cb70568abd?t=1446447776000" style="width: 709px; height: 140px;" /></td> </tr> <tr> <td> lame</td> <td> <img alt="Histogram of Lame Df values with native sound material" src="http://soundexpert.org/documents/10179/272881/kd2_lame.png/441dca08-6407-4118-933e-cd19ac7cb92e?t=1446447775000" style="width: 709px; height: 140px;" /></td> </tr> <tr> <td> ffv9b</td> <td> <img alt="Histogram of ffv9b Df values with native sound material" src="http://soundexpert.org/documents/10179/272881/kd2_ff9.png/d1d7c41b-0ac9-4477-a0a2-00b1b86a219d?t=1446447775000" style="width: 709px; height: 140px;" /></td> </tr> <tr> <td> ffv7</td> <td> <img alt="Histogram of ffv7 Df values with native sound material" src="http://soundexpert.org/documents/10179/272881/kd2_ff7.png/3c86947b-2622-4255-97f6-dfec83dec694?t=1446447775000" style="width: 709px; height: 140px;" /></td> </tr> </tbody> </table> <p> <strong>Figure 2</strong>. Histograms of Df values with native sound samples.</p> <p> </p> <p> So, we have five medians of Df values showing level of waveform degradation for the codecs:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 -22.1849 -26.4295 -22.6954 -20.1345 -19.5650</span></pre> <h3> Comparison of Df values with subjective scores</h3> <p> First, let's try linear best fit of those objective and subjective values:</p> <p style="margin-left: 40px;"> <code>df = [-22.1849 -26.4295 -22.6954 -20.1345 -19.5650];<br /> sq = [4.31 3.93 3.65 3.42 3.13]<br /> p = polyfit(df,sq,1);<br /> sqa = polyval(p,df)<br /> ((sqa-sq) ./ sq) * 100<br /> RMSE = sqrt(mean((sqa-sq).^2))</code></p> <p> </p> <p> <strong>Table 1</strong>. Results of analytically computed quality scores using linear model and Df values as predictor variables with corresponding errors and total RMSError.</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.69 4.12 3.74 3.48 3.42 Error -14.47% +4.91% +2.43% +1.62% +9.16% 0.32</span></pre> <p> </p> <p> While some errors are promising the whole picture is not encouraging – computed Opus score is too far (-14.5%) from its true value. The problem with aggregated Df values is that they do not take into account the type of waveform degradation, its nature. So we need some method to organize those Df values into groups with similar types of degradation. Required information about type of degradation is contained in full set of 3568 Df values. In fact, such Df sequence shows how different 400ms parts of audio signal were distorted during processing. Each Df sequence could be considered as a unique fingerprint of that particular processing. Thus, we can group/cluster those sequences according to their similarity to each other. Cluster analysis with correlation coefficient as a distance between sequences gives us the following result:</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Cluster analysis of Df sequences with native sound material" src="http://soundexpert.org/documents/10179/272881/X_codecs_kd74.png/aebce4a8-cf7f-4d72-80c3-e8c7db72184d?t=1446447779000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 3</strong>. Cluster analysis of Df sequences according to their similarity to each other.</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <p> The dendrogram clearly shows that Opus Df sequence differs from the others. It should be excluded from our analysis. Remaining four Df sequences have similar fingerprints (less than 0.1 units of distance) and we can compute quality scores for them once again:</p> <p style="margin-left: 40px;"> <code>df = [-26.4295 -22.6954 -20.1345 -19.5650];<br /> sq = [3.93 3.65 3.42 3.13]<br /> p = polyfit(df,sq,1);<br /> sqa = polyval(p,df)<br /> ((sqa-sq) ./ sq) * 100<br /> RMSE = sqrt(mean((sqa-sq).^2))</code></p> <p> </p> <p> <strong>Table 2</strong>. Results of analytically computed quality scores using linear model and Df values as predictor variables for the codecs excluding Opus.</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.97 3.58 3.32 3.26 Error +0.99% -1.83% -2.97% +4.14% 0.09</span></pre> <p> </p> <p> The fit is better now but it can be further improved. All SoundExpert experience with Difference level indicates that relationship between the latter and perceived sound quality is better modeled with second-order curve. Second-degree polinomial gives the following results:</p> <p style="margin-left: 40px;"> <code>df = [-26.4295 -22.6954 -20.1345 -19.5650];<br /> sq = [3.93 3.65 3.42 3.13]<br /> p = polyfit(df,sq,2);<br /> sqa = polyval(p,df)<br /> ((sqa-sq) ./ sq) * 100<br /> RMSE = sqrt(mean((sqa-sq).^2))</code></p> <p> </p> <p> <strong>Table 3</strong>. Results of analytically computed quality scores using second-order model and Df values as predictors:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.92 3.68 3.31 3.21 Error -0.15% +0.89% -3.10% +2.54% 0.07</span></pre> <p> </p> <p> And the fit can be improved even further using SoundExpert psychometric function which is in fact the same second-degree polinomial <em>Ax<sup>2</sup> + Bx + C</em> but only curves where <em>A>0</em> are used for modeling data. This function is used for calculation of “subjective” scores above 5-th grade in SE listening tests. In our case the function gives the following approximation to our true scores:</p> <p style="margin-left: 40px;"> <code>df = [-26.4295 -22.6954 -20.1345 -19.5650];<br /> sq = [3.93 3.65 3.42 3.13]<br /> sqa = sepsy(df, sq, df)<br /> er = ((sqa-sq) ./ sq) * 100<br /> RMSE = sqrt(mean((sqa-sq).^2))</code></p> <p> </p> <p> <strong>Table 4</strong>. Results of analytically computed (modeled) quality scores using SoundExpert psychometric function (SE model) and Df values as predictors:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.93 3.67 3.38 3.22 Error -0.11% +0.61% -1.29% +2.76% 0.05</span></pre> <p> </p> <p> It looks like this is the best fit we can get having the actual level of similarity for our Df sequences (error dependence on this similarity should be further researched).</p> <h3> Calculation of "missing" subjective scores</h3> <p> Now we are ready to perform an experiment aimed to show how good this methodology can predict results of the listening test. We will compute each of four quality scores (excluding Opus) using remaining three as inputs for our SE model. In other words, we will examine four cases of this listening test each time excluding one codec as if it did not participated in the test; subjective score of the “missing” codec will be computed analytically and can be compared with its true value.</p> <p style="margin-left: 40px;"> <code><span style="color:#008000;">% computing 'missing' Nero quality score</span><br /> DfN = -26.4295;<br /> SqN = 3.93;<br /> df = [-22.6954 -20.1345 -19.5650];<br /> sq = [3.65 3.42 3.13];<br /> sqaN = sepsy(df, sq, DfN)<br /> ErN = ((sqaN-SqN) ./ SqN) * 100</code></p> <p> </p> <p> <strong>Table 5</strong>. Results of analytically computed quality scores for “missing” codecs:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Missing Quality Score 3.85 3.70 3.32 3.36 Error -2.05% +1.24% -2.93% +7.43% 0.13</span></pre> <p> </p> <p> Overall error increased, which is expected as the number of points for building our second-order model reduced from 4 to 3. But 7.5% error for ffv7 codec is a real fail. Nevertheless, computing of “missing” scores seems to be an appropriate procedure for testing our Df approach and for further research of factors affecting errors. One such factor could be sound material.</p> <h3> Impact of sound material</h3> <p> Why not to try sound material other than the one used by Kamedo2 in his listening test. At the end, those 74 sound excerpts are representative to some bigger population of music material. Also it would be helpful to have an idea how music material affects Df values and corresponding errors. For the purpose we'll use two variants - the whole album “The Dark Side of the Moon” and a random sequence of 450 small (4s) sound excerpts seamlessly concatenated into one half-an-hour post-modern masterpiece :-) For the both cases we will compute <em>modeled</em> and <em>missing</em> quality scores with corresponding errors.</p> <p> </p> <h4> The Dark Side of the Moon (42:53)</h4> <p> </p> <p> We will repeat the whole procedure of Df measurements with the album “The Dark Side of the Moon” as we did with the native sound excerpts: coding --> decoding --> upsampling --> Df values (6430 values by 400ms). Histograms are below:</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> opus</td> <td> <img alt="Histogram of Opus Df values with "The Dark Side of the Moon"" src="http://soundexpert.org/documents/10179/272881/pf_opus.png/cfec25f3-14db-451f-a27c-00d16b5b0342?t=1446447778000" style="width: 709px; height: 189px;" /></td> </tr> <tr> <td> nero</td> <td> <img alt="Histogram of Nero Df values with "The Dark Side of the Moon"" src="http://soundexpert.org/documents/10179/272881/pf_nero.png/4539328c-7f49-49a4-a7a0-4b04100cfdd4?t=1446447778000" style="width: 709px; height: 164px;" /></td> </tr> <tr> <td> lame</td> <td> <img alt="Histogram of Lame Df values with "The Dark Side of the Moon"" src="http://soundexpert.org/documents/10179/272881/pf_lame.png/f142f30c-aa46-4c7c-859c-35e11841daf7?t=1446447777000" style="width: 709px; height: 164px;" /></td> </tr> <tr> <td> ffv9b</td> <td> <img alt="Histogram of ffv9b Df values with "The Dark Side of the Moon"" src="http://soundexpert.org/documents/10179/272881/pf_ff9.png/8796d86c-9af8-45c8-b078-44fa8a921fe8?t=1446447777000" style="width: 709px; height: 164px;" /></td> </tr> <tr> <td> ffv7</td> <td> <img alt="Histogram of ffv7 Df values with "The Dark Side of the Moon"" src="http://soundexpert.org/documents/10179/272881/pf_ff7.png/8157a16e-90a7-4481-9ae8-dbba2372a0af?t=1446447776000" style="width: 709px; height: 164px;" /></td> </tr> </tbody> </table> <p> <strong>Figure 4</strong>. Histograms of Df values with “The Dark Side of the Moon” album.</p> <p> </p> <p> We have five medians of Df values (dB) showing level of waveform degradation for the codecs with “The Dark Side of the Moon” album:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 -22.9455 -28.9768 -24.8911 -21.9785 -21.6071</span></pre> <p> </p> <p> Cluster analysis for these new Df sequences:</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Cluster analysis of Df sequences with "The Dark Side of the Moon" album" src="http://soundexpert.org/documents/10179/272881/X_codecs_pinkf.png/faa64fb2-52c9-4b9f-aee9-4093e02cb6c7?t=1446447780000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 5</strong>. Cluster analysis of Df sequences with “The Dark Side of the Moon” album.</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <p> Comparing to native sound material we can say that Lame became less similar to aac family codecs but still around 0.1 units of distance; distance to Opus increased slightly. Anyway, for research purposes we will retain previous conditions for Df – SQ comparison - Opus is excluded from analysis.</p> <p> </p> <p> <strong>Table 6</strong>. Modeled and <em>missing</em> quality scores with “The Dark Side of the Moon” album.</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.92 3.68 3.36 3.26 Error -0.13% +0.75% -1.76% +4.18% 0.07 Missing Quality Score 3.84 3.70 3.28 3.39 Error -2.36% +1.51% -4.11% +8.25% 0.16</span></pre> <p> </p> <p> Using "The Dark Side of the Moon" album instead of native sound material increased the errors but not dramatically, which is a bit surprising and inspiring. Let's see what will happen with errors in case of using diverse collection of small excerpts (450 items, 4s each) smoothly mixed one after another.</p> <p> </p> <h4> The Random Mix (30:00)</h4> <p> </p> <p> The whole research procedure is exactly the same. Histograms are below:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> opus</td> <td> <img alt="Histogram of Opus Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_opus.png/db57225f-479e-4408-9285-618496c130e2?t=1446447774000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> nero</td> <td> <img alt="Histogram of Nero Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_nero.png/dfc6e1c9-5cce-4cad-96e1-7faea510c07a?t=1446447773000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> lame</td> <td> <img alt="Histogram of Lame Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_lame.png/d3082f5f-5f9b-4255-ac4f-376b4ea6fb71?t=1446447773000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> ffv9b</td> <td> <img alt="Histogram of ffv9b Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_ff9.png/62b6bd59-0985-4795-88a3-d4aed4eeebaf?t=1446447772000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> ffv7</td> <td> <img alt="Histogram of ffv7 Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_ff7.png/5003fc2d-21e3-4678-8e04-c8ae6b65106e?t=1446447772000" style="width: 709px; height: 143px;" /></td> </tr> </tbody> </table> <p> <strong>Figure 6</strong>. Histograms of Df values with The Random Mix</p> <p> </p> <p> Five medians of Df values (dB) showing level of waveform degradation for the codecs with The Random Mix:</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 -23.4859 -28.7681 -24.7532 -22.4382 -21.6660</span></pre> <p> </p> <p> Cluster analysis:</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Cluster analysis of Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/X_codecs_450ff.png/1be97ae2-d54e-40f1-aad8-1c7741465b4f?t=1446447779000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 7</strong>. Cluster analysis of Df sequences with The Random Mix.</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <p> AAC family codecs look very similar now, Lame is still around 0.1 unit of distance from aac codecs, Opus still stands out from the others but to the less extent. Modeled and <em>missing</em> quality scores are below:</p> <p> </p> <p> <strong>Table 7</strong>. Modeled and <em>missing</em> quality scores with The Random Mix</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.93 3.66 3.40 3.19 Error -0.05% +0.27% -0.53% +1.89% 0.03 Missing Quality Score 3.89 3.67 3.38 3.31 Error -1.03% +0.56% -1.19% +5.86% 0.10</span></pre> <p> </p> <p> Results with arbitrary and highly diverse sound material are better than with the native one. This may happen thanks to unusually high number of sound excerpts (74) used in Kamedo2 listening test but this could also be a sign of more general regularity – the more audio material is used, the more level of its waveform degradation correlate with perceived audio quality. Shorter distances between Df sequences in cluster analysis with The Random Mix can be an indirect evidence of the latter. Experiment with substantially greater amount of audio material could be revealing in this sense. Also examination of other listening tests is necessary.</p> <h3> Adding new contenders to the listening test</h3> <p> As we have pretty good approximation to the true quality scores using SE model and The Random Mix (less than 2% error, Table 7), why not to add some new codec contenders to Kamedo2's listening test (hope he will not be against :). We will try three new codecs:</p> <p> libfdk-aac 3.4.12; VBR mode 2; 96.03 kbit/s<br /> fhgaac v03.02.16; VBR=3; 102.00 kbit/s<br /> CoreAudioToolbox 7.10.5.0; AAC-LC Encoder; TVBR q45; 94.25 kbit/s</p> <p> Random Mix was encoded/decoded with these new codecs and corresponding Df sequences were computed as usual:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> fdk</td> <td> <img alt="Histogram of fdk Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_fdk.png/1fff2b33-7a15-4853-8d5b-317ba3a9924e?t=1446447770000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> fhg</td> <td> <img alt="Histogram of fhg Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_fhg.png/0bed1298-aa90-4ad4-b09d-63c35529b72c?t=1446447772000" style="width: 709px; height: 143px;" /></td> </tr> <tr> <td> tvbr</td> <td> <img alt="Histogram of tvbr Df values with The Random Mix" src="http://soundexpert.org/documents/10179/272881/450ff_tvbr.png/d76f1ae0-ef2b-4e28-b879-8f6e50e604ba?t=1446447774000" style="width: 709px; height: 143px;" /></td> </tr> </tbody> </table> <p> <strong>Figure 8</strong>. Histograms of Df values of the new codecs with The Random Mix.</p> <p> </p> <p> Three medians of Df values (dB) showing level of waveform degradation for the new codecs:</p> <pre> <span style="font-size:14px;"> fdk fhg tvbr -27.6373 -29.8352 -23.4633</span></pre> <p> </p> <p> Cluster analysis:</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Cluster analysis of Df sequences with The Random Mix and newly added codecs." src="http://soundexpert.org/documents/10179/272881/X_codecs_450ff%2B.png/bd4db86b-cb59-45cb-be89-4a3e0d6f790b?t=1446447779000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 9</strong>. Cluster analysis of Df sequences with The Random Mix and newly added codecs.</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <p> Dendrogram clearly shows that aac codecs by Fraunhofer perfectly match our group (Nero and fdk are very very similar); tvbr aac codec from Apple is too far from them so we can't be sure that our model will work for it; we exclude it. Quality scores for remaining two codecs are computed using our second-order model.</p> <p> </p> <p> <strong>Table 8</strong>. Modeled quality scores of native and <em>post-test</em> codecs (with The Random Mix).</p> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 fdk fhg True Quality Score 4.31 3.93 3.65 3.42 3.13 Modeled Quality Score 3.93 3.66 3.40 3.19 3.86 3.99 Error -0.05% +0.27% -0.53% +1.89% Bitrate with The Random Mix, kbit/s 96.26 95.56 97.20 98.28 98.19 96.03 102.00</span></pre> <p> </p> <p> <img alt="“Extended” Kamedo2 listening test with computed quality scores" src="http://soundexpert.org/documents/10179/272881/sqs%2B_case1.png/da47ca13-f9bc-47c8-bfca-756944e5a146?t=1446447778000" style="width: 960px; height: 500px;" /></p> <p> <strong>Figure 10</strong>. “Extended” Kamedo2 listening test with quality scores computed as the function of Difference levels (black diamonds).</p> <p> </p> <p> Method of error estimation for such computed scores can be developed; there are two independent sources of the error – variance of true scores and non-similarity of Df sequences; bootstrapping may serve the purpose [more statistics and research needed].</p> <h3> <a id="clusteranalysis" name="clusteranalysis"></a>Cluster analysis</h3> <p style="margin-top:-15px;"> 2015 Nov 8</p> <p> Finding similar Df sequences is important for building the model; this affects accuracy of predictions. We use cluster analysis for the purpose. On the first stage the algorithm finds distances between all Df sequences using (1 – r) as a measure of distance, where r is a correlation coefficient.</p> <p> </p> <p> <strong>Table 9</strong>. Matrix of distances for Fig.3 as an example</p> <pre> <span style="font-size:14px;"> ffv7 ffv9 lame nero opus ffv7 0 0.0621 0.0887 0.0796 0.2497 ffv9 0.0621 0 0.1192 0.0765 0.2507 lame 0.0887 0.1192 0 0.1133 0.2149 nero 0.0796 0.0765 0.1133 0 0.2042 opus 0.2497 0.2507 0.2149 0.2042 0</span></pre> <p> </p> <p> Codecs with short distances between each other can be used for building the model. For ease of choosing the suitable codecs the matrix of distances can be visualized with dendrogram. It shows the distances between elements and clusters of elements with U-shaped lines. For computing distances between clusters several methods can be used. In the Figures 3,5,7,9 dendrograms were computed using smallest distance between objects in two clusters. In our research another method which uses largest distance between objects in two clusters is more appropriate because it guarantees that max distance within group doesn't exceed some predefined value. Below are dendrograms from figures 3,5,7,9 computed using largest distance side by side with the old ones computed using smallest distance.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Dendrogram from Fig.3 (smallest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_kd74_s.png/6a7d621d-f605-47f0-af94-a9dba897293e?t=1446976960000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrogram from Fig.3 (largest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_kd74_c.png/30f82184-fa3c-41ae-ba7e-879e46f0d5ba?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <strong>Figure 3.1</strong>. Dendrogram from Fig.3 (native sound material), computed using smallest distance between objects in two clusters (a) and using largest distance (b).</td> </tr> <tr> <td style="vertical-align: bottom; text-align: center;"> a)</td> <td style="text-align: center;"> b)</td> <td style="text-align: center;"> </td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Dendrogram from Fig.5 (smallest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_pinkf_s.png/e963631f-b6b0-4253-8784-49991beafa61?t=1446976961000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrogram from Fig.5 (largest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_pinkf_c.png/6836c1e1-3b07-4886-b03f-cc5de259cf3c?t=1446976961000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p> <strong>Figure 5.1</strong>. Dendrogram from Fig.5 (The Dark Side of the Moon), computed using smallest distance between objects in two clusters (a) and using largest distance (b).</p> </td> </tr> <tr> <td style="vertical-align: bottom; text-align: center;"> a)</td> <td style="text-align: center;"> b)</td> <td style="text-align: center;"> </td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Dendrogram from Fig.7 (smallest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_450ff_s.png/2b869242-4d23-4354-9731-5ea030ad23a0?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrogram from Fig.7 (largest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_450ff_c.png/5d099bc0-725c-4308-b9b9-cd179faa3985?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <strong>Figure 7.1</strong>. Dendrogram from Fig.7 (The Random Mix), computed using smallest distance between objects in two clusters (a) and using largest distance (b).</td> </tr> <tr> <td style="vertical-align: bottom; text-align: center;"> a)</td> <td style="text-align: center;"> b)</td> <td style="text-align: center;"> </td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Dendrogram from Fig.9 (smallest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_450ffplus_s.png/b96de011-1868-4b23-8ae6-5ef3ceb73934?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrogram from Fig.9 (largest distance)" src="http://soundexpert.org/documents/10179/272881/X_codecs_450ffplus_c.png/678de3b4-081f-4cc2-a74f-9f745a4f8057?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <strong>Figure 9.1</strong>. Dendrogram from Fig.9 (The Random Mix), computed using smallest distance between objects in two clusters (a) and using largest distance (b).</td> </tr> <tr> <td style="vertical-align: bottom; text-align: center;"> a)</td> <td style="text-align: center;"> b)</td> <td style="text-align: center;"> </td> </tr> </tbody> </table> <p> </p> <p> Using largest distance between objects in two clusters allows better control consistency of distances within group, reliably removing outliers which decrease accuracy of the model. At this stage of research the distance of 0.1 units (cor.coeff = 0.9) looks sufficient [further research needed].</p> <p> </p> <h4> Increasing amount of sound material</h4> <p> </p> <p> For these three codecs – fhg, nero, tvbr – additional experiment was performed. Two dendrograms were computed: with The Random Mix (30:00, 450 excerpts) and with the extended random mix (120:00, 1800 excerpts).</p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td> <img alt="Dendrogram for fhg, nero and tvbr codecs with 450 sound excerpts" src="http://soundexpert.org/documents/10179/272881/fhg-nero-tvbr_450.png/a6c9f7c1-3d3f-42f3-9518-08f647b7081b?t=1446976958000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrogram for fhg, nero and tvbr codecs with 1800 sound excerpts" src="http://soundexpert.org/documents/10179/272881/fhg-nero-tvbr_1800.png/5a614540-d30a-45b6-bc05-3ea5c9442b58?t=1446976959000" style="width: 401px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <strong>Figure 11</strong>. Dendrograms of the three codecs with 450 (a) and 1800 (b) random sound excerpts.</td> </tr> <tr> <td style="vertical-align: bottom; text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> <td style="text-align: center;"> </td> </tr> </tbody> </table> <p> </p> <p> </p> <p> <strong>Table 10</strong>. Df values and bitrates of the three codecs with 450 and 1800 sound excerpts extracted from different sound tracks of various genres.</p> <pre> <span style="font-size:14px;"> 450 excerpts 1800 excerpts Df,dB Bitrate,kbit/s Df,dB Bitrate,kbit/s fhg -29.8352 102.00 -30.0331 101.63 nero -28.7681 95.56 -29.0183 95.99 tvbr -23.4633 94.85 -23.5182 95.29</span></pre> <p> </p> <p> </p> <p> Increased amount of random sound material didn't worsen cluster separation; vice versa – separation slightly increased. [Optimal amount of sound material should be defined].</p> <h3> <a id="clusterrobust" name="clusterrobust"></a>... more of cluster analysis (the robust one)</h3> <p style="margin-top:-15px;"> 2016 Jul 12</p> <p> When Df sequences of the codecs were finally re-computed with higher precision (and different setting for time warping: 400ms instead of 30000ms used in previous low precision calculations), our cluster analysis showed different cluster separation of codecs.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Dendrograms of the codecs whose Df sequences were computed with low precisiond" src="http://soundexpert.org/documents/10179/272881/kd74_low_corr_complete.png/3ee11112-9e17-429f-ba4d-b1584d43a74e?t=1468320560000" style="width: 401px; height: 400px;" /></td> <td> <img alt="Dendrograms of the codecs whose Df sequences were computed with HIGH precision" src="http://soundexpert.org/documents/10179/272881/kd74_high_corr_complete.png/8b05a3ec-9a71-46f7-8304-3526efb8b6cc?t=1468320559000" style="width: 401px; height: 400px;" /></td> <td rowspan="2" style="vertical-align: bottom;"> <strong>Figure 12</strong>. Dendrograms of the codecs whose Df sequences were computed with low (a) and HIGH (b) precision. Our cluster analysis turned out to be too sensitive to the mode Df sequences were computed.</td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p> </p> <p> Preliminary research revealed that Pearson correlation as a measure of similarity between Df sequences is not robust enough against small random variations in those sequences (low and HIGH precision Df sequences have almost similar distributions and medians; their histograms are in Fig.16). Another measure of similarity should be found for our research. As we are interested in similarity of shapes of Df sequences the required measure most probably will be based on correlation. Two robust versions of correlation coefficient - Spearman's rank correlation and the recent Distance correlation [G. J. Szekely; M. L. Rizzo; N. K. Bakirov (2007), "Measuring and Testing Independence by Correlation of Distances"] – showed most promising results (Fig.13) and will be examined below.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 500px;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Dendrograms of the codecs computed using Pearson correlation" src="http://soundexpert.org/documents/10179/272881/kd74_low%2Bhigh_corr_complete.png/e0856408-22b6-443e-b2d0-cf52e3dcce46?t=1468320560000" style="width: 333px; height: 345px;" /></td> <td style="text-align: center;"> <img alt="Dendrograms of the codecs computed using Spearman's rank correlation" src="http://soundexpert.org/documents/10179/272881/kd74_low%2Bhigh_spear_complete.png/834e0df9-2b48-427b-828d-e24b77478d1b?t=1468320561000" style="width: 333px; height: 345px;" /></td> <td style="text-align: center;"> <img alt="Dendrograms of the codecs computed using Distance correlation" src="http://soundexpert.org/documents/10179/272881/kd74_low%2Bhigh_dcor_complete.png/076530e1-d018-45bc-9a6a-35ff2d7a3c4c?t=1468322403169" style="width: 333px; height: 345px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> <td style="text-align: center;"> (c)</td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <br /> <strong>Figure 13</strong>. Dendrograms of the codecs computed using different measures of similarity: Pearson correlation (a), Spearman's rank correlation (b) and Distance correlation (c). Both the low and HIGH precision versions of Df sequences are shown together to better reveal the problem with Pearson correlation. The latter not only failed to separate correctly the clusters of codecs but also failed to find correctly the similarities between the low and HIGH versions of the codecs' Df sequences (ffv7 and ffv9b).</p> <p> </p> <p> The figures clearly show that Spearman's rank correlation and Distance correlation perform much better and have close results. Let's find out if there is an advantage of one over another in our case. We already know for sure (and it was confirmed by previous cluster analyses) that Opus and AAC codecs belong to separate clusters. So we can estimate effectiveness of each measure of distance by computing average distance within AAC cluster (it must be minimal) and average distance between Opus and AAC codecs (it must be maximal). Results of such measurements (including Pearson correlation) are below.</p> <p> </p> <p> <strong>Table 11</strong>. Matrices of normalized distances (Dmax = 1) between codecs (Native sound samples (74), low precision) computed using different measures of distance/similarity and corresponding WITHIN and BETWEEN measurements for Opus and AAC clusters.</p> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tbody> <tr> <td> <p> <code>Native sound samples (74), low precision, D:<strong>correlation</strong><br /> ffv7 ffv9b lame nero opus<br /> ffv7 0 0.2475 0.3536 0.3173 0.9957<br /> ffv9b 0.2475 0 0.4753 0.3052 1.0000<br /> lame 0.3536 0.4753 0 0.4520 0.8572<br /> nero 0.3173 0.3052 0.4520 0 0.8142<br /> opus 0.9957 1.0000 0.8572 0.8142 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.28997 0.93663</code></td> </tr> <tr> <td> <p> <code>Native sound samples (74), low precision, D:<strong>spearman</strong><br /> ffv7 ffv9b lame nero opus<br /> ffv7 0 0.2323 0.5061 0.4111 0.9628<br /> ffv9b 0.2323 0 0.4785 0.4414 1.0000<br /> lame 0.5061 0.4785 0 0.4640 0.7919<br /> nero 0.4111 0.4414 0.4640 0 0.8670<br /> opus 0.9628 1.0000 0.7919 0.8670 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.36159 0.94327</code></td> </tr> <tr> <td> <p> <code>Native sound samples (74), low precision, D:<strong>distance correlation</strong><br /> ffv7 ffv9b lame nero opus <br /> ffv7 0 0.2722 0.5601 0.4266 0.9852<br /> ffv9b 0.2722 0 0.5321 0.4518 1.0000<br /> lame 0.5601 0.5321 0 0.5146 0.8275<br /> nero 0.4266 0.4518 0.5146 0 0.8563<br /> opus 0.9852 1.0000 0.8275 0.8563 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.38354 0.94718</code></td> </tr> </tbody> </table> <p> </p> <p> <br /> <strong>Table 12</strong>. Matrices of normalized distances (Dmax = 1) between codecs (Native sound samples (74), HIGH precision) computed using different measures of distance/similarity and corresponding WITHIN and BETWEEN measurements for Opus and AAC clusters.</p> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tbody> <tr> <td> <p> <code>Native sound samples (74), HIGH precision, D:<strong>correlation</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.1488 0.5572 0.4454 1.0000<br /> FFV9B 0.1488 0 0.6168 0.4500 0.9999<br /> LAME 0.5572 0.6168 0 0.3373 0.6671<br /> NERO 0.4454 0.4500 0.3373 0 0.6005<br /> OPUS 1.0000 0.9999 0.6671 0.6005 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.34805 0.86682</code></td> </tr> <tr> <td> <p> <code>Native sound samples (74), HIGH precision, D:<strong>spearman</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.2455 0.5043 0.3493 0.9496<br /> FFV9B 0.2455 0 0.4892 0.3883 1.0000<br /> LAME 0.5043 0.4892 0 0.4014 0.7905<br /> NERO 0.3493 0.3883 0.4014 0 0.8064<br /> OPUS 0.9496 1.0000 0.7905 0.8064 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.32772 0.91868</code></td> </tr> <tr> <td> <p> <code>Native sound samples (74), HIGH precision, D:<strong>distance correlation</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.2763 0.5627 0.3799 0.9783<br /> FFV9B 0.2763 0 0.5339 0.4054 1.0000<br /> LAME 0.5627 0.5339 0 0.4589 0.8211<br /> NERO 0.3799 0.4054 0.4589 0 0.7943<br /> OPUS 0.9783 1.0000 0.8211 0.7943 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.35387 0.9242</code></td> </tr> </tbody> </table> <p> <br /> <br /> <strong>Table 13</strong>. Matrices of normalized distances (Dmax = 1) between codecs (Random mix (450), low precision) computed using different measures of distance/similarity and corresponding WITHIN and BETWEEN measurements for Opus and AAC clusters.</p> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tbody> <tr> <td> <p> <code>Random mix (450), low precision, D:<strong>correlation</strong><br /> ffv7 ffv9b lame nero opus<br /> ffv7 0 0.3383 0.6134 0.3413 1.0000<br /> ffv9b 0.3383 0 0.6497 0.3932 0.9571<br /> lame 0.6134 0.6497 0 0.5230 0.9727<br /> nero 0.3413 0.3932 0.5230 0 0.8574<br /> opus 1.0000 0.9571 0.9727 0.8574 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.35761 0.93818</code></td> </tr> <tr> <td> <p> <code>Random mix (450), low precision, D:<strong>spearman</strong><br /> ffv7 ffv9b lame nero opus<br /> ffv7 0 0.3484 0.6350 0.3521 0.9615<br /> ffv9b 0.3484 0 0.6660 0.4232 1.0000<br /> lame 0.6350 0.6660 0 0.5007 0.9118<br /> nero 0.3521 0.4232 0.5007 0 0.8363<br /> opus 0.9615 1.0000 0.9118 0.8363 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.37459 0.93261</code></td> </tr> <tr> <td> <p> <code>Random mix (450), low precision, D:<strong>distance correlation</strong><br /> ffv7 ffv9b lame nero opus<br /> ffv7 0 0.3587 0.6884 0.3660 0.9944<br /> ffv9b 0.3587 0 0.7094 0.4325 1.0000<br /> lame 0.6884 0.7094 0 0.5574 0.9444<br /> nero 0.3660 0.4325 0.5574 0 0.8413<br /> opus 0.9944 1.0000 0.9444 0.8413 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.38576 0.94523</code></td> </tr> </tbody> </table> <p> <br /> <br /> <strong>Table 14</strong>. Matrices of normalized distances (Dmax = 1) between codecs (Random mix (450), HIGH precision) computed using different measures of distance/similarity and corresponding WITHIN and BETWEEN measurements for Opus and AAC clusters.</p> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tbody> <tr> <td> <p> <code>Random mix (450), HIGH precision, D:<strong>correlation</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.3522 0.6656 0.3142 0.9969<br /> FFV9B 0.3522 0 0.6958 0.4095 0.9786<br /> LAME 0.6656 0.6958 0 0.5914 1.0000<br /> NERO 0.3142 0.4095 0.5914 0 0.8701<br /> OPUS 0.9969 0.9786 1.0000 0.8701 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.35864 0.94854</code></td> </tr> <tr> <td> <p> <code>Random mix (450), HIGH precision, D:<strong>spearman</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.3341 0.6367 0.2843 0.9199<br /> FFV9B 0.3341 0 0.6945 0.4151 1.0000<br /> LAME 0.6367 0.6945 0 0.5340 0.9358<br /> NERO 0.2843 0.4151 0.5340 0 0.8338<br /> OPUS 0.9199 1.0000 0.9358 0.8338 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.34453 0.91792</code></td> </tr> <tr> <td> <p> <code>Random mix (450), HIGH precision, D:<strong>distance correlation</strong><br /> FFV7 FFV9B LAME NERO OPUS<br /> FFV7 0 0.3462 0.7014 0.3130 0.9601<br /> FFV9B 0.3462 0 0.7389 0.4260 1.0000<br /> LAME 0.7014 0.7389 0 0.5959 0.9681<br /> NERO 0.3130 0.4260 0.5959 0 0.8438<br /> OPUS 0.9601 1.0000 0.9681 0.8438 0</code></p> </td> <td style="text-align: center;"> <code>Average distance Average distance<br /> WITHIN aac cluster BETWEEN opus-aac<br /> 0.36173 0.93463</code></td> </tr> </tbody> </table> <p> <br /> <br /> From the tables:</p> <ul> <li> both Spearman's rank correlation and Distance correlation have close results;</li> <li> Spearman's rank correlation has slightly lower WITHIN values; this helps to better reveal the similarities within aac cluster.</li> <li> Distance correlation has slightly higher BETWEEN values; this helps to better reveal the distinctions between Opus and aac clusters;</li> <li> Pearson correlation has the best WITHIN-BETWEEN values in all cases except where it fails completely (Native sound samples (74), HIGH precision).</li> </ul> <p> <br /> It looks like both Spearman and Distance correlations should be used in our audio research for better consistency of results.<br /> <br /> And finally we should choose the right linkage method for building dendrograms, the one, which better visualizes distance information contained in distance matrices and thus gives correct clusterization of codecs. We will examine three well-known methods - single, complete and average linkages and the new one – E-clustering [Gabor J. Szekely; Maria L. Rizzo (2012), "Energy statistics: A class of statistics based on distances"]. It must be noted that the use of E-clustering is questionable in our case because the method is defined for Euclidean distances (metric spaces) only. In general case distances produced by correlation measurements belong to non-metric space. However, triangle inequality test applied to our distance matrices revealed that all of them comply with the test. The exceptions are distance matrices for the cases of the low/HIGH precision Df sequences being analyzed together (Fig.13). In these cases triangle inequality holds for ~98% of all possible distance triangles between 10 codecs. Perhaps, if triangle inequality holds for 100%, then the distances could be treated as Euclidean [further research needed]. So, we will use E-clustering method in our case with caution, as an experiment.<br /> <br /> In order to estimate effectiveness of these four methods of linkage we will use cophenetic correlation coefficient, which measures how good a dendrogram represent the distances from distance matrix. The higher the value (Cph <= 1) the better dendrogram reflects similarity/dissimilarity between codecs.<br /> <br /> Df sequences for native sound samples (74) and random mix (450), both computed with low and HIGH precision, will be used for our linkage test. Three such dendrograms for complete linkage and three measures of distance (Pearson correlation, Spearman correlation, Distance correlation) were already shown in Fig.13. Now we'll plot the whole set of dendrograms for these three measures of distance and the four linkage methods - single, complete, average, E-clustering. For each dendrogram the cophenetic correlation coefficients will be computed. Resulting plots are below.</p> <p> </p> <p> <img alt="Dendrograms of the codecs with the native sound samples (74)" src="http://soundexpert.org/documents/10179/272881/kd74_low%2Bhigh.png/3a19b5d2-bbcb-48a3-8b2b-d461ea4f9e8f?t=1468320560000" style="width: 1000px; height: 940px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 14</strong>. Dendrograms of the codecs with the native sound samples (74). Df sequences for the codecs were computed twice - with low and the HIGH precision (ten sequences in total). The dendrograms were plotted using three measures of distance and four linkage methods.</p> <p> </p> <p> From the figure:</p> <ul> <li> the right column (DHL) corresponding to E-clustering is a Grey area as the use of this method is questionable due to non-metric nature of our distances/similarities between Df sequences (~98% compliance with triangle inequality test);</li> <li> Pearson correlation as a measure of distance gives wrong clustering of codecs (ABCD); combination of Spearman correlation and E-clustering (H) also fails; all wrong dendrograms have lower cophenetic correlation and marked reddish;</li> <li> combination of Spearman/Distance correlations and single/complete/average linkages (EFGIJK) gives consistent and predictable clustering; they are greenish;</li> <li> for all linkage methods Distance correlation has slightly higher cophenetic correlation (IJKL);</li> <li> for all measures of distance average linkage has slightly higher cophenetic correlation (CGK);</li> <li> combination of Distance correlation and E-clustering (L) gives the best separation of the codecs; also this combination is outstanding in determination of similarities between the low and HIGH versions of the same codecs (lowest linkages between the versions); also for all measures of distance E-clustering (DHL) gives the lowest linkages between the low and HIGH versions of the same codecs.</li> </ul> <p> </p> <img alt="Dendrograms of the codecs with the random mix (450)" src="http://soundexpert.org/documents/10179/272881/450_low%2Bhigh.png/c0a5e0dd-9c8b-4fe5-aa6b-6651dadb5d27?t=1468320559000" style="width: 1000px; height: 940px;" /><br /> <p style="margin-left: 40px;"> <strong>Figure 15</strong>. Dendrograms of the codecs with the random mix (450). Df sequences for the codecs were computed twice - with low and HIGH precision (ten sequences in total). The dendrograms were plotted using three measures of distance and four linkage methods.</p> <p> </p> <p> From the figure:</p> <ul> <li> the right column (DHL) corresponding to E-clustering is a Grey area as the use of this method is questionable due to non-metric nature of our distances/similarities between Df sequences (~98% compliance with triangle inequality test);</li> <li> in case of the random mix (450) all combinations of distance measures and linkages give similar results (all greenish); there are some differences within aac cluster in case of complete linkage (BFJ) but these dendrograms have slightly lower cophenetic correlation;</li> <li> for all linkage methods Pearson correlation has slightly higher cophenetic correlation (ABCD); Distance correlation is the second;</li> <li> for all measures of distance average linkage has slightly higher cophenetic correlation (CGK);</li> <li> as in previous case with the native sound samples (74) combination of Distance correlation and E-clustering (L) gives the best separation of the codecs; also this combination is outstanding in determination of similarities between the low and HIGH versions of the same codecs (lowest linkages between the versions); also for all measures of distance E-clustering (DHL) gives the lowest linkages between the low and HIGH versions of the same codecs.</li> </ul> <p> </p> <p> Conclusion: for consistent and reliable cluster analysis (which plays important role in our audio research) it is advisable to use at least two different ways of clusterization; one – more classical – Spearman's rank correlation + average linkage, which is simple and easy to interpret; another – more sophisticated – Distance correlation + E-clustering, which is surprisingly powerful but has questionable correctness in our case (results of triangle inequality test must be supplied).</p> <h3> <a id="rmethod" name="rmethod"></a>The research method</h3> <p style="margin-top:-15px;"> 2016 Jul 29</p> <p> Finally the methods and research instruments have been pretty defined.</p> <p> In each listening test case we will compare objective measurements with subjective scores using two types of audio material:</p> <ul> <li> native sound samples that were used during listening test - <em>Native Audio</em></li> <li> one and the same random mix consisting of 450 short (4sec) sound samples of various artists - <em>The Random Mix</em>, 30min</li> </ul> <p> Objective measurements will be represented by sequences of Df values showing degradation of initial waveform piece-wise with 0.4sec window (and 0.4sec frame for time warping). Histograms of the sequences with medians and percentiles will be provided.</p> <p> Comparison of Df sequences with each other will be performed by means of cluster analysis using two measures of distance:</p> <ul> <li> Spearman's rank correlation</li> <li> Distance correlation</li> </ul> <p> and two linkage methods:</p> <ul> <li> average linking for Spearman's rank correlation</li> <li> energy linking for Distance correlation (results of triangle inequality test will be provided)</li> </ul> <p> Upon the results of the cluster analysis a group of codecs with similar nature of waveform degradation will be chosen and be used for further research. For such codec group average distance within group and max distance will be provided (for both distance measures).</p> <p> For chosen group of codecs the simple regression analysis will be performed using quadratic curve fitting between medians of Df sequences and corresponding subjective scores. Differences (residuals) between true subjective scores and the ones predicted by the model will be provided (as in Table 4).</p> <p> In accordance with this methodology the research case with kamedo2 listening test can be summarized as follows.</p> <p> </p> <h4> 1. True subjective scores.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 15</strong>. Subjective quality scores from the listening test.</p> <pre style="margin-left: 40px;"> <span style="font-size:14px;">opus nero lame ffv9b ffv7 4.31 3.93 3.65 3.42 3.13</span></pre> <h4> </h4> <h4> 2. Df measurements.</h4> <p> </p> <table align="center" border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td colspan="2" style="text-align: center;"> OPUS</td> </tr> <tr> <td style="text-align: center;"> <img alt="kd74_opus" src="http://soundexpert.org/documents/10179/541837/kd74_opus.png/89175161-3075-4258-85c9-678abbfcf834?t=1469786465000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="450_opus" src="http://soundexpert.org/documents/10179/541837/450_opus.png/bb16fca1-139d-4f80-bea4-21ef4c3e49c8?t=1469786463000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> NERO</td> </tr> <tr> <td style="text-align: center;"> <img alt="kd74_nero" src="http://soundexpert.org/documents/10179/541837/kd74_nero.png/3bb0788c-e2a2-426f-b836-3aa66ffcb640?t=1469786465000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="450_nero" src="http://soundexpert.org/documents/10179/541837/450_nero.png/2dc4f4f1-14fc-4cd6-8dfd-f972d40589c6?t=1469786463000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> LAME</td> </tr> <tr> <td style="text-align: center;"> <img alt="kd74_lame" src="http://soundexpert.org/documents/10179/541837/kd74_lame.png/c08da4d7-2eba-49ee-ab35-a405a2adda2c?t=1469786465000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="450_lame" src="http://soundexpert.org/documents/10179/541837/450_lame.png/07cc3518-44e3-41b2-9e7a-33757a210d65?t=1469786463000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> FFV9B</td> </tr> <tr> <td style="text-align: center;"> <img alt="kd74_ffv9b" src="http://soundexpert.org/documents/10179/541837/kd74_ff9.png/a973d89f-e701-4c55-90d0-7cad220c40eb?t=1469786465000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="450_ffv9" src="http://soundexpert.org/documents/10179/541837/450_ff9.png/849e66d3-37c5-40e6-bb72-d373d6a2dc92?t=1469786463000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> FFV7</td> </tr> <tr> <td style="text-align: center;"> <img alt="kd74_ffv7" src="http://soundexpert.org/documents/10179/541837/kd74_ff7.png/ea52133b-6f09-4401-a09f-ae5c9dad3273?t=1469786464000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="450_ffv7" src="http://soundexpert.org/documents/10179/541837/450_ff7.png/d670a2e0-bed6-43cc-97c2-22dcab5bf802?t=1469786462000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 16</strong>. Df measurements with native audio material (a) and the random mix (b).</p> <p> </p> <h4> 3. Cluster analysis</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 16</strong>. Distances between codecs with native audio material (left) and the random mix (right) and two measures of distance: Spearman's rank correlation (top) and Distance correlation (bottom). All distances comply with triangle inequality test.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <p> <code> <span style="background-color:#afeeee;">FFV7</span> <span style="background-color:#afeeee;">FFV9B</span> <span style="background-color:#afeeee;">LAME</span> <span style="background-color:#afeeee;">NERO</span> OPUS<br /> <span style="background-color:#afeeee;">FFV7</span> 000000 <span style="background-color:#afeeee;">0.0465</span> <span style="background-color:#afeeee;">0.0954</span> <span style="background-color:#afeeee;">0.0661</span> 0.1797<br /> <span style="background-color:#afeeee;">FFV9B</span> 0.0465 000000 <span style="background-color:#afeeee;">0.0926</span> <span style="background-color:#afeeee;">0.0735</span> 0.1892<br /> <span style="background-color:#afeeee;">LAME</span> 0.0954 0.0926 000000 <span style="background-color:#afeeee;">0.0760</span> 0.1496<br /> <span style="background-color:#afeeee;">NERO</span> 0.0661 0.0735 0.0760 000000 0.1526<br /> OPUS 0.1797 0.1892 0.1496 0.1526 000000</code></p> <p> <code> </code></p> </td> <td> <p> <code> <span style="background-color:#afeeee;">FFV7</span> <span style="background-color:#afeeee;">FFV9B</span> <span style="background-color:#afeeee;">LAME</span> <span style="background-color:#afeeee;">NERO</span> OPUS <br /> <span style="background-color:#afeeee;">FFV7</span> 000000 <span style="background-color:#afeeee;">0.0507</span> <span style="background-color:#afeeee;">0.0966</span> <span style="background-color:#afeeee;">0.0431</span> 0.1396<br /> <span style="background-color:#afeeee;">FFV9B</span> 0.0507 000000 <span style="background-color:#afeeee;">0.1054</span> <span style="background-color:#afeeee;">0.0630</span> 0.1517<br /> <span style="background-color:#afeeee;">LAME</span> 0.0966 0.1054 000000 <span style="background-color:#afeeee;">0.0810</span> 0.1420<br /> <span style="background-color:#afeeee;">NERO</span> 0.0431 0.0630 0.0810 000000 0.1265<br /> OPUS 0.1396 0.1517 0.1420 0.1265 000000</code></p> <p> </p> </td> </tr> <tr> <td> <p> <code> <span style="background-color:#afeeee;">FFV7</span> <span style="background-color:#afeeee;">FFV9B</span> <span style="background-color:#afeeee;">LAME</span> <span style="background-color:#afeeee;">NERO</span> OPUS <br /> <span style="background-color:#afeeee;">FFV7</span> 000000 <span style="background-color:#afeeee;">0.0597</span> <span style="background-color:#afeeee;">0.1216</span> <span style="background-color:#afeeee;">0.0821</span> 0.2113<br /> <span style="background-color:#afeeee;">FFV9B</span> 0.0597 000000 <span style="background-color:#afeeee;">0.1153</span> <span style="background-color:#afeeee;">0.0876</span> 0.2160<br /> <span style="background-color:#afeeee;">LAME</span> 0.1216 0.1153 000000 <span style="background-color:#afeeee;">0.0991</span> 0.1774<br /> <span style="background-color:#afeeee;">NERO</span> 0.0821 0.0876 0.0991 000000 0.1716<br /> OPUS 0.2113 0.2160 0.1774 0.1716 000000</code></p> </td> <td> <p> <code> <span style="background-color:#afeeee;">FFV7</span> <span style="background-color:#afeeee;">FFV9B</span> <span style="background-color:#afeeee;">LAME</span> <span style="background-color:#afeeee;">NERO</span> OPUS <br /> <span style="background-color:#afeeee;">FFV7</span> 000000 <span style="background-color:#afeeee;">0.0634</span> <span style="background-color:#afeeee;">0.1284</span> <span style="background-color:#afeeee;">0.0573</span> 0.1757<br /> <span style="background-color:#afeeee;">FFV9B</span> 0.0634 000000 <span style="background-color:#afeeee;">0.1352</span> <span style="background-color:#afeeee;">0.0780</span> 0.1830<br /> <span style="background-color:#afeeee;">LAME</span> 0.1284 0.1352 000000 <span style="background-color:#afeeee;">0.1091</span> 0.1772<br /> <span style="background-color:#afeeee;">NERO</span> 0.0573 0.0780 0.1091 000000 0.1544<br /> OPUS 0.1757 0.1830 0.1772 0.1544 000000</code></p> </td> </tr> </tbody> </table> <br /> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="kd74_spear_average" src="http://soundexpert.org/documents/10179/541837/kd74_spear_average.png/dffaff58-c34d-42c7-afe0-8cff00abe4ef?t=1469786466000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="kd74_dcorr_e-link" src="http://soundexpert.org/documents/10179/541837/kd74_dcorr_e-link.png/992b1a28-c9b3-48c6-bf18-fb0bee090a95?t=1469786464000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="450_spear_average" src="http://soundexpert.org/documents/10179/541837/450_spear_average.png/dda2bbfa-4ed4-4358-a18f-1dea7c2c0fbf?t=1469786464000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="450_dcorr_e-link" src="http://soundexpert.org/documents/10179/541837/450_dcorr_e-link.png/fe739519-1180-45cd-9377-8d30a511cc44?t=1469786462000" style="width: 249px; height: 300px;" /></td> </tr> <tr> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> </tr> <tr> <td colspan="2" rowspan="1" style="text-align: center;"> (a)<br /> </td> <td colspan="2" rowspan="1" style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 17</strong>. Dendrograms of codecs with native audio material (a) and the random mix (b), computed using two clusterization methods: Spearman's rank correlation with average linking (c) and Distance correlation with energy linking (d). Cophenetic correlation shows how good dendrogram represents distances between codecs from distance matrix (Coph <= 1).</p> <p> </p> <p> Group of AAC codecs + Lame are chosen for further regression analysis (marked with color in distance matrices, Table 16 ).</p> <p> </p> <p style="margin-left: 40px;"> <strong>Table 17</strong>. Average and Max distances within chosen codecs with native audio material (left) and the random mix (right) and two measures of distance: Spearman's rank correlation (top) and Distance correlation (bottom).</p> <table border="0" cellpadding="0" cellspacing="10" style="width: 100%;"> <tbody> <tr> <td> <code>Average distance (Spearman) within the group: 0.0750<br /> Max distance (Spearman) within<code> the</code> group: <code>0.0954</code></code><br /> </td> <td> <code>Average distance (Spearman) within the group: 0.0733<br /> Max distance (Spearman) within <code>the</code> group: <code>0.1054</code></code><br /> </td> </tr> <tr> <td> <code>Average distance (dCorr) within <code>the</code> group: 0.0942<br /> Max distance (dCorr) within <code>the</code> group: <code>0.1216</code></code></td> <td> <code>Average distance (dCorr) within <code>the</code> group: 0.0952<br /> Max distance (dCorr) within <code>the</code> group: <code>0.1352</code></code></td> </tr> </tbody> </table> <p> </p> <p> </p> <h4> 4. Regression analysis.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 18</strong>. True and predicted quality scores with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <pre> <span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True QS 4.31 3.93 3.65 3.42 3.13 Predicted QS 3.92 3.68 3.37 3.21 Error -0.14% +0.77% -1.59% +2.53% 0.0501</span></pre> </td> <td> <pre> <span style="font-size:14px;"><span style="font-size:14px;"> opus nero lame ffv9b ffv7 RMSEr True QS 4.31 3.93 3.65 3.42 3.13 Predicted QS 3.93 3.66 3.41 3.18 Error -0.04% +0.21% -0.41% +1.58% 0.0259</span></span></pre> </td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Best fit with native audio material" src="http://soundexpert.org/documents/10179/541837/kd74_regress.png/5088767b-5784-47ef-bbeb-511c574b2657?t=1469786466000" style="width: 498px; height: 400px;" /></td> <td style="text-align: center;"> <img alt="Best fit with the random mix" src="http://soundexpert.org/documents/10179/541837/450_regress.png/63e76e59-870c-45ad-b37d-0babf15893e7?t=1469786463000" style="width: 498px; height: 400px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 18</strong>. Best quadratic fit between Df measurements and true quality scores with native audio material (a) and the random mix (b).</p> <p> </p> <p> Below are Df vs. QS scatter plots for all 74 native samples encoded with separate codecs. The first plot corresponds to Fig.18(a). The relationship between Df and QS - less obvious, though - can be seen not only for different codecs but also for different samples encoded with a single codec.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Df vs. QS scatter plot for native samples encoded with NERO, LAME, FFV7, FFV9B" src="http://soundexpert.org/documents/10179/541837/c1_native_scatter.png/ce2cd15b-c153-4a23-851c-a2274427af62?t=1474102914000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for native samples encoded with OPUS" src="http://soundexpert.org/documents/10179/541837/c1_native_opus_scatter.png/12f158ac-d2f7-4db9-95e2-89deda723147?t=1474102913000" style="width: 500px; height: 400px;" /></td> </tr> <tr> <td> <img alt="Df vs. QS scatter plot for native samples encoded with NERO" src="http://soundexpert.org/documents/10179/541837/c1_native_nero_scatter.png/98104d61-dc99-4d9b-94eb-cfb4f2e74738?t=1474102913000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for native samples encoded with LAME" src="http://soundexpert.org/documents/10179/541837/c1_native_lame_scatter.png/5bedc3fc-6d26-4ff1-8bf7-49525c3b2513?t=1474102912000" style="width: 500px; height: 400px;" /></td> </tr> <tr> <td> <img alt="Df vs. QS scatter plot for native samples encoded with FFV7" src="http://soundexpert.org/documents/10179/541837/c1_native_ffv7_scatter.png/dd907c6e-d4ee-422b-b2b0-b23b87718a7b?t=1474102910000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for native samples encoded with FFV9B" src="http://soundexpert.org/documents/10179/541837/c1_native_ffv9b_scatter.png/5a19f51e-c4cf-4699-966d-2ae0bd1ff5f1?t=1474102911000" style="width: 500px; height: 400px;" /></td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 19</strong>. Difference Level vs. Quality score scatter plots for 74 native samples.</p> <p> </p> <p> </p> <h2> <span style="font-size:18px;"><strong><a id="case2" name="case2"></a>Case #2. Public multiformat listening test (July 2014) (33 listeners)</strong></span></h2> <p style="text-align: right;"> 2016 Sep 10</p> <p> </p> <p> Results of this test along with all supplemental materials were published here - <a href="http://listening-test.coresv.net/results.htm" target="_blank">http://listening-test.coresv.net/results.htm</a>. The test was performed mostly by listeners from HydrogenAudio forum using 40 sound samples.</p> <p> Encoders:<br /> Opus 1.1 with opus-tools-0.1.9-win32<br /> AAC iTunes 11.2.2 via qaac 2.41 (CoreAudioToolbox 7.9.8.5)<br /> Ogg Vorbis aoTuV Beta6.03 [20110424]<br /> MP3 LAME 3.99.5<br /> FAAC-1.28-mod from RareWares<br /> <br /> Settings:<br /> opusenc --bitrate 96 in.wav out.opus<br /> qaac --cvbr 96 -o out.mp4 in.wav<br /> venc603 -q2.2 in.wav out.ogg<br /> lame -V5 in.wav out.mp3<br /> faac -b 96 in.wav<br /> faac -q 30 in.wav<br /> <br /> Samples:<br /> Total 40 samples (5 sets, 8 samples each).<br /> </p> <h4> 1. True subjective scores.</h4> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Results of HA2014 listening test" src="http://soundexpert.org/documents/10179/576582/scores_by_tracks_en.png/1e0f0370-9a98-423e-8b0c-a2ad79d43672?t=1473510327000" style="width: 720px; height: 450px; float: left;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 201</strong>. Results of HA2014 listening test.</p> </td> </tr> </tbody> </table> <p> </p> <p style="margin-left: 40px;"> <strong>Table 201</strong>. Subjective quality scores from the listening test.</p> <pre> <span style="font-size:14px;">AppleAAC Opus Ogg MP3V5 FAAC96k FAACq30 4.400 4.653 4.235 4.237 2.652 1.194</span></pre> <p> </p> <h4> </h4> <h4> 2. Df measurements.</h4> <p> </p> <table align="center" border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td colspan="2" style="text-align: center;"> Opus</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_opus" src="http://soundexpert.org/documents/10179/576582/opus_ha2014.png/9ae42e5f-a326-4712-b99b-e7fbcd02848d?t=1473510326000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="451_opus" src="http://soundexpert.org/documents/10179/576582/opus_451.png/60b76327-d64b-4ef1-95db-385f22a57980?t=1473510326000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> AAC</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_aac" src="http://soundexpert.org/documents/10179/576582/aac_ha2014.png/152e4aed-c368-462d-a2fc-10a54c256703?t=1473510320000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="451_aac" src="http://soundexpert.org/documents/10179/576582/aac_451.png/1c874226-abe1-4a48-97d0-fcc024f51e65?t=1473510320000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> Ogg</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_ogg" src="http://soundexpert.org/documents/10179/576582/ogg_ha2014.png/cb4f5cd2-e703-4b4a-aa1e-e06f12d0c9cf?t=1473510326000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="451_ogg" src="http://soundexpert.org/documents/10179/576582/ogg_451.png/02bdab27-6860-4205-bfff-bd9be83eee33?t=1473510325000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> MP3</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_mp3" src="http://soundexpert.org/documents/10179/576582/mp3_ha2014.png/53f5000e-a3e7-453d-8856-766fbb9c930e?t=1473510325000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="451_mp3" src="http://soundexpert.org/documents/10179/576582/mp3_451.png/f1746897-73aa-49d2-a018-c18c8e2faf8f?t=1473510324000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> FAAC96k</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_faac96k" src="http://soundexpert.org/documents/10179/576582/faac96k_ha2014.png/7f96b476-be0c-4940-a99e-1154a07d44c4?t=1473510322000" style="width: 451px; height: 143px;" /></td> <td style="text-align: center;"> <img alt="451_faac96k" src="http://soundexpert.org/documents/10179/576582/faac96k_451.png/3a43a276-aa83-415f-a0c0-a79ca2a5fbbd?t=1473510322000" style="width: 451px; height: 143px;" /></td> </tr> <tr> <td colspan="2" style="text-align: center;"> FAACq30</td> </tr> <tr> <td style="text-align: center;"> <img alt="ha2014_faacq30" src="http://soundexpert.org/documents/10179/576582/faacq30_ha2014.png/6012d7ef-7ec5-4f2b-92f4-512c6c06db23?t=1473510323000" style="width: 451px; height: 169px;" /></td> <td style="text-align: center;"> <img alt="451_faacq30" src="http://soundexpert.org/documents/10179/576582/faacq30_451.png/15c6aa86-35a1-414f-be4f-f9dfa20a7ec2?t=1473510322000" style="width: 451px; height: 169px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 202</strong>. Df measurements with native audio material (a) and the random mix (b).</p> <p> </p> <p> </p> <h4> 3. Cluster analysis</h4> <br /> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="ha2014_spear_average" src="http://soundexpert.org/documents/10179/576582/case2_native_spear_average.png/09a62e9c-9439-41a1-8602-775c59b84e1d?t=1473510322000" style="width: 249px; height: 309px;" /></td> <td style="text-align: center;"> <img alt="ha2014_dcorr_e-link" src="http://soundexpert.org/documents/10179/576582/case2_native_dcor_elink.png/339ef1e2-b517-45aa-898e-56f95974966d?t=1473510321000" style="width: 249px; height: 309px;" /></td> <td style="text-align: center;"> <img alt="451_spear_average" src="http://soundexpert.org/documents/10179/576582/case2_451_spear_average.png/79022c50-3991-4071-99e3-327688e01464?t=1473510321000" style="width: 249px; height: 309px;" /></td> <td style="text-align: center;"> <img alt="451_dcorr_e-link" src="http://soundexpert.org/documents/10179/576582/case2_451_dcor_elink.png/a356a53c-8c9b-4bd2-9811-b9e021cbf268?t=1473510320000" style="width: 249px; height: 309px;" /></td> </tr> <tr> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> </tr> <tr> <td colspan="2" rowspan="1" style="text-align: center;"> (a)<br /> </td> <td colspan="2" rowspan="1" style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 203</strong>. Dendrograms of codecs with native audio material (a) and the random mix (b), computed using two clusterization methods: Spearman's rank correlation with average linking (c) and Distance correlation with energy linking (d). Cophenetic correlation shows how good dendrogram represents distances between codecs from distance matrix (Coph <= 1).</p> <p> </p> <p> In this listening test all codecs are very different by type of waveform degradation (distances between them are much higher than in Case 1, Fig.17). Nevertheless, in order to estimate the influence of increased distances we will perform usual regression analysis for the group of four codecs: MP3, FAAC96k, Ogg, FAACq30.</p> <p> </p> <p style="margin-left: 40px;"> <strong>Table 202</strong>. Distances between codecs with native audio material (left) and the random mix (right) and two measures of distance: Spearman's rank correlation (top) and Distance correlation (bottom). All distances comply with triangle inequality test. The chosen codecs and distances between them are marked with color.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <pre> Opus AAC <span style="background-color:#afeeee;">Ogg</span> <span style="background-color:#afeeee;">MP3</span> <span style="background-color:#afeeee;">FAAC96k</span> <span style="background-color:#afeeee;">FAACq30</span> Opus 000000 0.1569 0.1249 0.1229 0.1769 0.1926 AAC 0.1569 000000 0.1895 0.1574 0.1868 0.2105 <span style="background-color:#afeeee;">Ogg</span> 0.1249 0.1895 000000 <span style="background-color:#afeeee;">0.1128</span> <span style="background-color:#afeeee;">0.1468</span> <span style="background-color:#afeeee;">0.1137</span> <span style="background-color:#afeeee;">MP3</span> 0.1229 0.1574 0.1128 000000 <span style="background-color:#afeeee;">0.0990</span> <span style="background-color:#afeeee;">0.1595</span> <span style="background-color:#afeeee;">FAAC96k</span> 0.1769 0.1868 0.1468 0.0990 000000 <span style="background-color:#afeeee;">0.1407</span> <span style="background-color:#afeeee;">FAACq30</span> 0.1926 0.2105 0.1137 0.1595 0.1407 000000</pre> <p> <code> </code></p> </td> <td> <pre> Opus AAC <span style="background-color:#afeeee;">Ogg</span> <span style="background-color:#afeeee;">MP3</span> <span style="background-color:#afeeee;">FAAC96k</span> <span style="background-color:#afeeee;">FAACq30</span> Opus 000000 0.2104 0.1546 0.1510 0.2391 0.2464 AAC 0.2104 000000 0.1932 0.1827 0.2387 0.2031 <span style="background-color:#afeeee;">Ogg</span> 0.1546 0.1932 000000 <span style="background-color:#afeeee;">0.1180</span> <span style="background-color:#afeeee;">0.1908</span> <span style="background-color:#afeeee;">0.1141</span> <span style="background-color:#afeeee;">MP3</span> 0.1510 0.1827 0.1180 000000 <span style="background-color:#afeeee;">0.1168</span> <span style="background-color:#afeeee;">0.1472</span> <span style="background-color:#afeeee;">FAAC96k</span> 0.2391 0.2387 0.1908 0.1168 000000 <span style="background-color:#afeeee;">0.1648</span> <span style="background-color:#afeeee;">FAACq30</span> 0.2464 0.2031 0.1141 0.1472 0.1648 000000</pre> <p> </p> </td> </tr> <tr> <td> <pre> Opus AAC <span style="background-color:#afeeee;">Ogg</span> <span style="background-color:#afeeee;">MP3</span> <span style="background-color:#afeeee;">FAAC96k</span> <span style="background-color:#afeeee;">FAACq30</span> Opus 000000 0.1835 0.1514 0.1491 0.1975 0.2119 AAC 0.1835 000000 0.2157 0.1823 0.2094 0.2351 <span style="background-color:#afeeee;">Ogg</span> 0.1514 0.2157 000000 <span style="background-color:#afeeee;">0.1365</span> <span style="background-color:#afeeee;">0.1696</span> <span style="background-color:#afeeee;">0.1287</span> <span style="background-color:#afeeee;">MP3</span> 0.1491 0.1823 0.1365 000000 <span style="background-color:#afeeee;">0.1224</span> <span style="background-color:#afeeee;">0.1861</span> <span style="background-color:#afeeee;">FAAC96k</span> 0.1975 0.2094 0.1696 0.1224 000000 <span style="background-color:#afeeee;">0.1603</span> <span style="background-color:#afeeee;">FAACq30</span> 0.2119 0.2351 0.1287 0.1861 0.1603 000000</pre> </td> <td> <pre> Opus AAC <span style="background-color:#afeeee;">Ogg</span> <span style="background-color:#afeeee;">MP3</span> <span style="background-color:#afeeee;">FAAC96k</span> <span style="background-color:#afeeee;">FAACq30</span> Opus 000000 0.2415 0.1788 0.1882 0.2677 0.2708 AAC 0.2415 000000 0.2219 0.2172 0.2696 0.2338 <span style="background-color:#afeeee;">Ogg</span> 0.1788 0.2219 000000 <span style="background-color:#afeeee;">0.1478</span> <span style="background-color:#afeeee;">0.2143</span> <span style="background-color:#afeeee;">0.1332</span> <span style="background-color:#afeeee;">MP3</span> 0.1882 0.2172 0.1478 000000 <span style="background-color:#afeeee;">0.1437</span> <span style="background-color:#afeeee;">0.1744</span> <span style="background-color:#afeeee;">FAAC96k</span> 0.2677 0.2696 0.2143 0.1437 000000 <span style="background-color:#afeeee;">0.1800</span> <span style="background-color:#afeeee;">FAACq30</span> 0.2708 0.2338 0.1332 0.1744 0.1800 000000</pre> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> <strong>Table 203</strong>. Average and Max distances within codecs with native audio material (left) and the random mix (right) and two measures of distance: Spearman's rank correlation (top) and Distance correlation (bottom).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> </td> <td> Native sound samples</td> <td> The random mix</td> </tr> <tr> <td> <p> Average / Max<br /> Spearman's correlation distances<br /> </p> </td> <td> 0.1288 / 0.1595</td> <td> 0.14195 / 0.1908</td> </tr> <tr> <td> Average / Max<br /> Distance correlation distances</td> <td> 0.1506 / 0.1861</td> <td> 0.16556 / 0.2143</td> </tr> </tbody> </table> <p> </p> <br /> <p> </p> <h4> 4. Regression analysis.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 204</strong>. True and predicted quality scores with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <pre> <span style="font-size:14px;"> MP3 Ogg FAAC96k FAACq30 RMSEr True QS 4.2370 4.2350 2.6520 1.1940 Computed QS 4.5192 3.5343 3.0328 1.2318 Error 6.6602% -16.5466<span style="font-size:14px;">%</span> 14.3580<span style="font-size:14px;">%</span> 3.1642<span style="font-size:14px;">%</span> 0.4234</span></pre> </td> <td> <pre> <span style="font-size:14px;"><span style="font-size:14px;"><span style="font-size:14px;"> MP3 Ogg FAAC96k FAACq30 RMSEr True QS 4.2370 4.2350 2.6520 1.1940 Computed QS 4.5012 3.6501 2.9690 1.1976 Error 6.2355<span style="font-size:14px;">%</span> -13.8106<span style="font-size:14px;">%</span> 11.9549<span style="font-size:14px;">%</span> 0.3047<span style="font-size:14px;">%</span> 0.3579</span></span></span></pre> </td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Best fit with native audio material" src="http://soundexpert.org/documents/10179/576582/c2_native_regress.png/8c4d485c-2f0d-4723-a99d-622fa08b44a4?t=1493250407000" style="width: 498px; height: 400px;" /></td> <td style="text-align: center;"> <img alt="Best fit with the random mix" src="http://soundexpert.org/documents/10179/576582/c2_451_regress.png/e608945a-9ecd-4dd8-a76c-d226b29b5de4?t=1493250440000" style="width: 498px; height: 400px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 204</strong>. Best fit (linear) between Df measurements and true quality scores with native audio material (a) and the random mix (b). Codecs not used for computing approximation curves are red.</p> <p> </p> <p> The errors are expectedly higher. Below are Df vs. QS scatter plots for all 40 native samples.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with Ogg, MP3, FAAC96k, FAACq30" src="http://soundexpert.org/documents/10179/576582/c2_native_scatter.png/920f1576-9646-4339-b355-bf6a1ebca0f4?t=1474114797000" style="width: 500px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 205</strong>. Df vs. QS scatter plot for 40 native samples encoded with Ogg, MP3, FAAC96k, FAACq30. This is detailed view of averaged quality scores from Fig.204(a)</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with AAC" src="http://soundexpert.org/documents/10179/576582/c2_native_aac_scatter.png/9b5bc983-1213-43a0-ba27-819a36984062?t=1474114795000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with Opus" src="http://soundexpert.org/documents/10179/576582/c2_native_opus_scatter.png/3eddf627-6792-4eff-89a6-3123438a0615?t=1474114797000" style="width: 500px; height: 400px;" /></td> </tr> <tr> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with Ogg" src="http://soundexpert.org/documents/10179/576582/c2_native_ogg_scatter.png/e2ee63f2-14ed-4a1f-a581-7b706eba8de5?t=1474114797000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with MP3" src="http://soundexpert.org/documents/10179/576582/c2_native_mp3_scatter.png/2668935c-1a08-47b8-9bea-f1c329a5e7bd?t=1474114796000" style="width: 500px; height: 400px;" /></td> </tr> <tr> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with FAAC96k" src="http://soundexpert.org/documents/10179/576582/c2_native_FAAC96k_scatter.png/b5821c0d-630d-4cde-808f-ac948495902b?t=1474114795000" style="width: 500px; height: 400px;" /></td> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with FAACq30" src="http://soundexpert.org/documents/10179/576582/c2_native_FAACq30_scatter.png/d207f1aa-2c7a-45d7-be7f-8549d306b9fd?t=1474114795000" style="width: 500px; height: 400px;" /></td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 206</strong>. Difference Level vs. Quality score scatter plots for 40 native samples.</p> <p> </p> <p> </p> <p> </p> <h2> <span style="font-size:18px;"><strong><a id="case3" name="case3"></a>Case #3. Public AAC Listening Test @ 96 kbps (July 2011)</strong></span></h2> <p style="text-align: right;"> 2016 Sep 20</p> <p> Results of this test are published here - <a href="http://listening-tests.hydrogenaud.io/igorc/aac-96-a/results.html" target="_blank">http://listening-tests.hydrogenaud.io/igorc/aac-96-a/results.html</a>. The test was performed at HydrogenAudio forum by 25 listeners.</p> <p> Encoders and settings:</p> <ul> <li> Nero 1.5.4<br /> -q 0.345</li> <li> QuickTime 7.6.9, True VBR, via qtaacenc 20101119<br /> --tvbr 46 --highest --samplerate keep</li> <li> QuickTime 7.6.9, Constrained VBR, via qtaacenc 20101119<br /> --cvbr 96 --highest --samplerate keep</li> <li> Fraunhofer IIS, via Winamp 5.62<br /> VBR 3</li> <li> Coding Technologies, via Winamp 5.61<br /> CBR 100 kbps (.ini file edit to get 100kbps)</li> <li> ffmpeg's AAC (Lavf53.5.0) @ 96 kbps, Low Anchor<br /> -acodec aac -ab 96k -strict experimental</li> </ul> <p> During the listening test low anchor test files were encoded with ffmpeg build that is no longer in repository. For this research the nearest build was used - ffmpeg-0.8-win64-static (Lavf53.4.0) - which gives difference in third digit after the decimal point in Df measurements. Decoder - Foobar2000 v1.3.11 (32 bit output).<br /> <br /> Samples: 20 - <a href="https://hydrogenaud.io/index.php/topic,89208.msg763168.html#msg763168" target="_blank">https://hydrogenaud.io/index.php/topic,89208.msg763168.html#msg763168</a><br /> </p> <h4> 1. True subjective scores.</h4> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Results of HA2011 listening test" src="http://soundexpert.org/documents/10179/586661/nonblocked_means_all.png/298084a8-75a1-4902-89c5-be087aaed35c?t=1474362427000" style="width: 800px; height: 600px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 301</strong>. Results of HA2011 listening test.</p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <p style="margin-left: 40px;"> <strong>Table 301</strong>. Subjective quality scores from the listening test.</p> <pre> <span style="font-size:14px;">Nero CVBR TVBR FhG CT low_anchor 3.698 4.391 4.342 4.253 4.039 1.545</span></pre> <p> </p> <h4> </h4> <h4> 2. Df measurements.</h4> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Histogram of Df measurements with native samples for Nero" src="http://soundexpert.org/documents/10179/586661/c3_native_nero.png/36f081e1-bdd4-4c04-9a43-e61c003eba10?t=1474362421000" style="width: 451px; height: 143px; float: left;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">Nero</span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for Nero" src="http://soundexpert.org/documents/10179/586661/c3_trmx_nero.png/8398cec1-c8c1-4977-824c-ba75c034d643?t=1474362426000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for CVBR" src="http://soundexpert.org/documents/10179/586661/c3_native_cvbr.png/98a1e8d0-a2af-466e-b211-8e4df32a88b1?t=1474362416000" style="float: left; width: 451px; height: 143px;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">CVBR </span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for CVBR" src="http://soundexpert.org/documents/10179/586661/c3_trmx_cvbr.png/461452bf-c390-4e45-97ef-e7c5767b6141?t=1474362424000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for TVBR" src="http://soundexpert.org/documents/10179/586661/c3_native_tvbr.png/4704d283-6098-4cbf-82ae-b2086f4b145a?t=1474362423000" style="float: left; width: 451px; height: 143px;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">TVBR</span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for TVBR" src="http://soundexpert.org/documents/10179/586661/c3_trmx_tvbr.png/a4a558c6-0df3-4d6c-8785-08ebae4f23c1?t=1474362427000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for FhG" src="http://soundexpert.org/documents/10179/586661/c3_native_fhg.png/9d3eff7d-6431-4d94-8398-a3fbe317b3ae?t=1474362418000" style="float: left; width: 451px; height: 143px;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">FhG</span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for FhG" src="http://soundexpert.org/documents/10179/586661/c3_trmx_fhg.png/18873b47-a3eb-4413-b5cb-f0e8b88774b7?t=1474362425000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for CT" src="http://soundexpert.org/documents/10179/586661/c3_native_ct.png/939dd32e-6461-4bf1-b5b0-f291284cdf6b?t=1474362414000" style="float: left; width: 451px; height: 143px;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">CT</span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for CT" src="http://soundexpert.org/documents/10179/586661/c3_trmx_ct.png/3a2c2ea2-2228-4d3c-8c93-b1eccbfc9cce?t=1474362424000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for low anchor" src="http://soundexpert.org/documents/10179/586661/c3_native_anchor.png/23883429-a6e4-48da-b48e-433b590569f9?t=1474362413000" style="float: left; width: 451px; height: 143px;" /></td> <td> <pre style="text-align: center;"> <span style="font-size:14px;">ffmpeg (anchor)</span></pre> </td> <td> <img alt="Histogram of Df measurements with the random mix for low anchor" src="http://soundexpert.org/documents/10179/586661/c3_trmx_anchor.png/eb54ff5b-0143-4ac9-83a8-279d09d3b2c9?t=1474362423000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td> </td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 302</strong>. Df measurements with native audio material (a) and the random mix (b).</p> <p> </p> <p> </p> <h4> 3. Cluster analysis</h4> <br /> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="ha2011_spear_average" src="http://soundexpert.org/documents/10179/586661/c3_native_spearmancorr.png/2c3108f1-bb7f-49f9-82d4-fd3919778ffb?t=1474362422000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="ha2011_dcorr_e-link" src="http://soundexpert.org/documents/10179/586661/c3_native_distancecorr.png/735534fd-a699-4f6a-bdc4-34941976e268?t=1474362418000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="trmx_spear_average" src="http://soundexpert.org/documents/10179/586661/c3_trmx_spearmancorr.png/2593d0d4-ed2a-49e2-9ac6-8fd764424b98?t=1474362426000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="trmx_dcorr_e-link" src="http://soundexpert.org/documents/10179/586661/c3_trmx_distancecorr.png/2a061558-c225-4062-9ecd-083a1fba23fc?t=1474362424000" style="width: 249px; height: 300px;" /></td> </tr> <tr> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> </tr> <tr> <td colspan="2" rowspan="1" style="text-align: center;"> (a)<br /> </td> <td colspan="2" rowspan="1" style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 303</strong>. Dendrograms of codecs with native audio material (a) and the random mix (b), computed using two clusterization methods: Spearman's rank correlation with average linking (c) and Distance correlation with energy linking (d). Cophenetic correlation (Coph <= 1) shows how good dendrogram represents distances between codecs from distance matrix.</p> <p> </p> <p> According to above clusterization only three codecs (FhG, Nero, CT) have similar nature of waveform degradation which is insufficient for our regression analysis, so we will use four codecs: FhG, Nero, CT and ffmpeg (anchor); they form the next cluster (with higher within distances though). Tables with distances can be found in <a href="http://soundexpert.org/documents/10179/586661/c3_mesurements.txt/7db29b1f-f00d-4351-ab48-5be1de64392a" target="_blank">c3_mesurements.txt</a>.</p> <br /> <p style="margin-left: 40px;"> <strong>Table 302</strong>. Average and Max distances within chosen codecs with native audio material (left) and the random mix (right) and two measures of distance: Spearman's rank correlation (top) and Distance correlation (bottom).</p> <pre> <span style="font-size:14px;"> Native samples The random mix Average / Max Spearman's correlation distance 0.0780 / 0.1511 0.0855 / 0.1513 Average / Max Distance correlation distance 0.0955 / 0.1784 0.0991 / 0.1637</span></pre> <p> </p> <h4> 4. Regression analysis.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 303</strong>. True and computed quality scores with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <pre> <span style="font-size:14px;"> FhG CT Nero anchor RMSEr True QS 4.2530 4.0390 3.6980 1.5450 Computed QS 4.3546 3.4044 4.0420 1.7341 Error +2.39% -15.71% +9.30% +12.24% 0.3766</span></pre> </td> <td> <pre> <span style="font-size:14px;"> FhG CT Nero anchor RMSEr True QS 4.2530 4.0390 3.6980 1.5450 Computed QS 4.3858 3.3481 4.0267 1.7743 Error +3.12% -17.11% +8.89% +14.84% 0.4048</span></pre> </td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Best fit with native audio material" src="http://soundexpert.org/documents/10179/586661/c3_native_regress.png/b433bd5a-326a-40ad-a8e5-26b5d019e486?t=1474362421000" style="width: 498px; height: 400px;" /></td> <td style="text-align: center;"> <img alt="Best fit with the random mix" src="http://soundexpert.org/documents/10179/586661/c3_trmx_regress.png/ca047e30-3801-4e33-afdb-1f93cb978ba3?t=1474362426000" style="width: 498px; height: 400px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <strong>Figure 304</strong>. Best fit between Df measurements and true quality scores with native audio material (a) and the random mix (b); in both cases best fit is achieved with linear approximation.</p> <p> </p> <p> <strong>NB!</strong> Here we have the first disturbing surprise - loss of monotony of Df/QS dependency for two codecs (Nero, CT); both codecs have very similar nature of waveform degradation but lower Df values correspond to lower quality scores [should be investigated further]. </p> <p> Below are Df vs. QS scatter plots for all 20 native samples.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Df vs. QS scatter plot for 40 native samples encoded with Nero, FhG, CT, ffmpeg" src="http://soundexpert.org/documents/10179/586661/c3_native_scatter.png/7dcecd51-f84a-4f35-8abe-1e9fd0aa510d?t=1474362422000" style="width: 500px; height: 400px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 305</strong>. Df vs. QS scatter plot for 20 native samples encoded with Nero, FhG, CT, ffmpeg (anchor). This is detailed view of the averaged quality scores from Fig.304(a).</p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_cvbr_scatter.png/be0ddd7c-cc39-4ee2-8f1b-a8f28584f533?t=1474362417000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with CVBR" src="http://soundexpert.org/documents/10179/586661/c3_native_cvbr_scatter.png/be0ddd7c-cc39-4ee2-8f1b-a8f28584f533?t=1474362417000" style="width: 166px; height: 133px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_tvbr_scatter.png/fa7635f8-164f-484a-a153-096f4aa303b5?t=1474362423000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with TVBR" src="http://soundexpert.org/documents/10179/586661/c3_native_tvbr_scatter.png/fa7635f8-164f-484a-a153-096f4aa303b5?t=1474362423000" style="width: 166px; height: 133px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_nero_scatter.png/db9e7841-5404-4617-94bf-e1f19366d5e9?t=1474362421000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with Nero" src="http://soundexpert.org/documents/10179/586661/c3_native_nero_scatter.png/db9e7841-5404-4617-94bf-e1f19366d5e9?t=1474362421000" style="width: 166px; height: 133px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_fhg_scatter.png/102fc7f4-d126-4fbd-b547-57e0e06e9676?t=1474362419000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with FhG" src="http://soundexpert.org/documents/10179/586661/c3_native_fhg_scatter.png/102fc7f4-d126-4fbd-b547-57e0e06e9676?t=1474362419000" style="width: 166px; height: 133px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_ct_scatter.png/82349890-d0a2-4e3a-a21f-83334df0f2d8?t=1474362414000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with CT" src="http://soundexpert.org/documents/10179/586661/c3_native_ct_scatter.png/82349890-d0a2-4e3a-a21f-83334df0f2d8?t=1474362414000" style="width: 166px; height: 133px;" /></a></td> <td> <a href="http://soundexpert.org/documents/10179/586661/c3_native_anchor_scatter.png/e23f7fff-f5ab-45cf-80d1-27ea5aad8c08?t=1474362414000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=600,height=500'); return false;"><img alt="Df vs. QS scatter plot for 20 native samples encoded with ffmpeg (anchor)" src="http://soundexpert.org/documents/10179/586661/c3_native_anchor_scatter.png/e23f7fff-f5ab-45cf-80d1-27ea5aad8c08?t=1474362414000" style="width: 166px; height: 133px;" /></a></td> </tr> </tbody> </table> <p style="margin-left: 40px;"> <br /> <strong>Figure 306</strong>. Difference Level vs. Quality score scatter plots for 20 native samples.</p> <p> </p> <p> </p> <h2> <span style="font-size:18px;"><strong><a id="case4" name="case4"></a>Case #4. Public MP3 Listening Test @ 128 kbps (October 2008)</strong></span></h2> <p style="text-align: right;"> 2016 Oct 7</p> <p> Results of this test are published here - <a href="http://listening-tests.hydrogenaud.io/sebastian/mp3-128-1/results.htm" target="_blank">http://listening-tests.hydrogenaud.io/sebastian/mp3-128-1/results.htm</a>. The test was performed at HydrogenAudio forum by 26-39 listeners.</p> <p> Encoders and settings:</p> <ul> <li> LAME 3.98.2<br /> -V5.7</li> <li> LAME 3.97<br /> -V5 --vbr-new</li> <li> iTunes 8.0.1.11 (one core)<br /> 112 kbps, VBR, highest quality, joint stereo, smart coding, filter below 10 Hz</li> <li> Fraunhofer IIS CL encoder v1.5<br /> -br 0 -m 4 -q 1 -vbri -ofl</li> <li> Helix v5.1 2005.08.09<br /> -X2 -U2 -V60</li> <li> l3enc 0.99a (Low Anchor)<br /> -br 128000 -mod 1</li> </ul> <p> Decoders: Foobar2000 v1.3.11 (32 bit output) and mp3surround decoder.<br /> <br /> Samples: 14 (listed on the results page). Three samples (Vangelis_Chariots_of_Fire, White_Stripes_Hypnotize, sfbay) were not available at the time of the research and they were guessed from full tracks using info from forum discussions and their resulting bitrates.</p> <p> </p> <h4> 1. True subjective scores.</h4> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Results of HA08@128 listening test" src="http://soundexpert.org/documents/10179/604198/results.png/2e7546c7-c3a7-4cb6-b3b4-b00e43427d8c?t=1475849819000" style="width: 579px; height: 370px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 401</strong>. Results of HA08@128 listening test with mp3 only encoders.</p> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> <strong>Table 401</strong>. Subjective quality scores from the listening test.</p> <pre> <span style="font-size:14px;">Helix Lame3982 FhG Lame397 iTunes l3enc 4.59 4.51 4.44 4.28 4.26 1.56</span></pre> <p> </p> <h4> </h4> <h4> 2. Df measurements.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 402</strong>. Df measurements with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Histogram of Df measurements with native samples for Helix" src="http://soundexpert.org/documents/10179/604198/c4_native_helix.png/66301640-896a-41d9-9631-176a4dd2e7ff?t=1475849813000" style="width: 451px; height: 143px; float: left;" /></td> <td> <p style="text-align: center;"> Helix</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Helix" src="http://soundexpert.org/documents/10179/604198/c4_trmx_helix.png/6bc65c12-43c7-4ff6-a16d-70ebcba053fb?t=1475849816000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for Lame 3.98.2" src="http://soundexpert.org/documents/10179/604198/c4_native_lame98.png/78a4b833-bf5c-4e62-b534-483dcd336073?t=1475849814000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> Lame3982</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Lame 3.98.2" src="http://soundexpert.org/documents/10179/604198/c4_trmx_lame98.png/5c582bb4-2fa4-4d0c-a33c-ab544b3db6bb?t=1475849817000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for FhG" src="http://soundexpert.org/documents/10179/604198/c4_native_fhg.png/22cd32bf-a367-4c36-8db1-dad4933a5479?t=1475849811000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> FhG</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for FhG" src="http://soundexpert.org/documents/10179/604198/c4_trmx_fhg.png/b830c70f-55b1-45e0-9745-721f1549ecb5?t=1475849816000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for Lame 3.97" src="http://soundexpert.org/documents/10179/604198/c4_native_lame97.png/1a2e116f-3666-464d-9f62-4078b9566a0e?t=1475849814000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> Lame397</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Lame 3.97" src="http://soundexpert.org/documents/10179/604198/c4_trmx_lame97.png/95b89dc8-c888-41fb-8395-2d36fb1da993?t=1475849817000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for iTunes" src="http://soundexpert.org/documents/10179/604198/c4_native_itunes.png/2a2f1cdb-8990-4f42-aae5-6ec72baba5dc?t=1475849813000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> iTunes</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for iTunes" src="http://soundexpert.org/documents/10179/604198/c4_trmx_itunes.png/5cc1122a-c095-4a8e-8c24-b10ed9bcbc82?t=1475849817000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for l3enc" src="http://soundexpert.org/documents/10179/604198/c4_native_l3enc.png/782e4ea6-3a68-4a5c-85ea-88e34751a90d?t=1475849814000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> l3enc</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for l3enc" src="http://soundexpert.org/documents/10179/604198/c4_trmx_l3enc.png/58d17ae5-5f4f-4e1b-a416-4e3763996816?t=1475849817000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td> </td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p> </p> <h4> 3. Cluster analysis</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 403</strong>. Dendrograms of codecs with native audio material (a) and the random mix (b), computed using two clusterization methods: Spearman's rank correlation with average linking (c) and Distance correlation with energy linking (d). Cophenetic correlation shows how good dendrogram represents distances between codecs from distance matrix (Coph <= 1).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="HA08@128_spear_average" src="http://soundexpert.org/documents/10179/604198/dendro_c4_native_spear.png/81d34c2d-623f-4525-9ce3-0d2e3a3bd069?t=1475849818000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA08@128_dcorr_e-link" src="http://soundexpert.org/documents/10179/604198/dendro_c4_native_dcor.png/957ff2c5-b6ed-44f8-9d27-0580cd3dc54a?t=1475849818000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA08@128_trmx_spear_average" src="http://soundexpert.org/documents/10179/604198/dendro_c4_trmx_spear.png/ea90aa4b-4b0e-4974-8683-bbe5fef71c85?t=1475849819000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA08@128_trmx_dcorr_e-link" src="http://soundexpert.org/documents/10179/604198/dendro_c4_trmx_dcor.png/a34fc415-e6e8-46e9-90f9-e643da5061f8?t=1475849819000" style="width: 249px; height: 300px;" /></td> </tr> <tr> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> </tr> <tr> <td colspan="2" rowspan="1" style="text-align: center;"> (a)<br /> </td> <td colspan="2" rowspan="1" style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p> </p> <p> According to above clusterization only four MP3 codecs (Lame397, Lame3982, FhG, Helix) have similar nature of waveform degradation. Tables with distances between them can be found in <a href="http://soundexpert.org/documents/10179/604198/c4_mesurements.txt/78c7624a-d782-49aa-b16f-c4c4fdaee611" target="_blank">c4_mesurements.txt</a>. Also clusterization with the random mix differs from the one with native samples; probably this is due to small number of samples used in this listening test (14).</p> <br /> <p style="margin-left: 40px;"> <strong>Table 402</strong>. Average and Max distances within chosen codecs with native audio material and the random mix and two measures of distance: Spearman's rank correlation and Distance correlation.</p> <pre> <span style="font-size:14px;"> Native samples The random mix Average / Max Spearman's correlation distance 0.1131 / 0.1730 0.0800 / 0.1196 Average / Max Distance correlation distance 0.1342 / 0.1918 0.1004 / 0.1494</span></pre> <p> </p> <h4> 4. Regression analysis.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Table 403</strong>. True and computed quality scores with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <pre> <span style="font-size:14px;"> Helix Lame3982 FhG Lame397 RMSEr True QS 4.5900 4.5100 4.4400 4.2800 Computed QS 4.5712 4.4129 4.5108 4.3251 Error -0.41% -2.15% +1.60% +1.05% 0.0649</span></pre> </td> <td> <pre> <span style="font-size:14px;"> Helix Lame3982 FhG Lame397 RMSEr True QS 4.2530 4.0390 3.6980 1.5450 Computed QS 4.5674 4.4088 4.5127 4.3310 Error -0.49% -2.24% +1.64% +1.19% 0.0682</span></pre> </td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p> </p> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 404</strong>. Best fit between Df measurements and true quality scores with native audio material (a) and the random mix (b). Codecs not used for computing approximation curves are red.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Best fit with native audio material" src="http://soundexpert.org/documents/10179/604198/c4_native_regress.png/2b312938-f10b-4e87-b90d-911c2cdfc4f4?t=1475849815000" style="width: 490px; height: 400px; float: left;" /></td> <td style="text-align: center;"> <img alt="Best fit with the random mix" src="http://soundexpert.org/documents/10179/604198/c4_trmx_regress.png/20993fc1-13eb-4ff8-8649-7a77612afcea?t=1475849818000" style="width: 490px; height: 400px; float: right;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p> Though iTunes MP3 encoder also fits the curve well, this is assumed to be by chance as its type of waveform degradation differs substantially from the others. Indirect prove of the assumption - four chosen codecs preserve their relative positions both with native and random sound material while iTunes changes its position relative to that group.</p> <p> Scatter plots of individual samples are well-predictable and similar in all cases - clouds around their averages. They are not very informative and will not be provided for the time being.</p> <p> </p> <p> </p> <p> </p> <h2> <span style="font-size:18px;"><strong><a id="case5" name="case5"></a>Case #5. Public Multiformat Listening Test @ ~64 kbps (March 2011)</strong></span></h2> <p style="text-align: right;"> 2017 Apr 23</p> <p> Results of this test are published here - <a href="http://listening-tests.hydrogenaud.io/igorc/results.html" target="_blank">http://listening-tests.hydrogenaud.io/igorc/results.html</a>. The test was performed at HydrogenAudio forum by 31 listeners (not all listeners tested all samples).</p> <p> Encoders and settings:</p> <ul> <li> Nero 1.5.4.0 HE-AAC<br /> -q 0.245</li> <li> Ogg Vorbis AoTuV 6.02 Beta<br /> -q 0.1</li> <li> Apple QuickTime 7.6.9 HE-AAC<br /> constrained VBR, high quality, 64 kbps</li> <li> CELT 0.11.2 (March 2011) http://www.celt-codec.org/<br /> complexity 10, VBR 67.5 kbps</li> <li> iTunes AAC 7.6.9 (Low Anchor)<br /> 48 kbps, CBR</li> </ul> <p> Decoders: faad, seltdec, oggdec (the ones used during the test).<br /> <br /> Samples: 30 (can be downloaded from the results page above).</p> <p> </p> <h4> 1. True subjective scores.</h4> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Results of multiformat HA11@64 listening test" src="http://soundexpert.org/documents/10179/776162/nonblocked_means_all.png/370a55d1-627b-4269-995a-3329bfb5c47d?t=1492977554000" style="width: 800px; height: 600px;" /></td> <td style="vertical-align: bottom;"> <p style="margin-left: 40px;"> <strong>Figure 501</strong>. Results of multiformat HA11@64 listening test (30 samples, 531 results).</p> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> </p> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p style="margin-left: 40px;"> <strong>Table 501</strong>. Subjective quality scores from the listening test.</p> <pre> <span style="font-size:14px;">Vorbis Nero_HE-AAC Apple_HE-AAC Opus AAC-LC@48k 3.513 3.547 3.817 3.999 1.656</span></pre> <p> </p> <h4> </h4> <h4> 2. Df measurements.</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 502</strong>. Df measurements with native audio material (a) and the random mix (b).</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Histogram of Df measurements with native samples for Vorbis" src="http://soundexpert.org/documents/10179/776162/c5_native_vorbis.png/5166846b-ca48-4cc2-9620-8f18a7959009?t=1492978157000" style="width: 451px; height: 143px; float: left;" /></td> <td> <p style="text-align: center;"> Vorbis</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Vorbis" src="http://soundexpert.org/documents/10179/776162/c5_trmx_vorbis.png/5423c57e-c8af-4239-8484-3eb0849504f8?t=1492978315000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for Nero HE-AAC" src="http://soundexpert.org/documents/10179/776162/c5_native_nero.png/2df85dd0-293f-40b4-82f6-683ffcb83d4d?t=1492978313000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> Nero HE-AAC</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Nero HE-AAC" src="http://soundexpert.org/documents/10179/776162/c5_trmx_nero.png/531d2217-1b7e-4d3b-8b52-7dd577d0996a?t=1492978314000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for Apple HE-AAC" src="http://soundexpert.org/documents/10179/776162/c5_native_apple.png/30168cfb-efab-48a0-8fec-472771e06b3d?t=1492978313000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> Apple HE-AAC</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Apple HE-AAC" src="http://soundexpert.org/documents/10179/776162/c5_trmx_apple.png/bce379ac-c2f0-4e1d-bae1-ce1712bf3008?t=1492978314000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for Opus" src="http://soundexpert.org/documents/10179/776162/c5_native_opus.png/899e2f5e-1e4e-4360-ab14-c564e0a458c2?t=1492978313000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> Opus</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for Opus" src="http://soundexpert.org/documents/10179/776162/c5_trmx_opus.png/efb6b438-b153-45c9-9c20-10ed607a67b4?t=1492978314000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td> <img alt="Histogram of Df measurements with native samples for AAC-LC@48k" src="http://soundexpert.org/documents/10179/776162/c5_native_aac48.png/f8e401ea-403d-4fd0-9361-601b9e2fb8c0?t=1492978313000" style="float: left; width: 451px; height: 143px;" /></td> <td> <p style="text-align: center;"> AAC-LC@48k</p> </td> <td> <img alt="Histogram of Df measurements with the random mix for AAC-LC@48k" src="http://soundexpert.org/documents/10179/776162/c5_trmx_aac48.png/c3fbede9-7514-40ea-a08c-b643617963d9?t=1492978314000" style="float: right; width: 451px; height: 143px;" /></td> </tr> <tr> <td style="text-align: center;"> (a)</td> <td> </td> <td style="text-align: center;"> (b)</td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p> </p> <h4> 3. Cluster analysis</h4> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 503</strong>. Dendrograms of distances between codecs with native audio material (a) and the random mix (b), computed using two clusterization methods: Spearman's rank correlation with average linking (c) and Distance correlation with energy linking (d). Cophenetic correlation (Coph <= 1) shows how good dendrogram represents distances between codecs from distance matrix.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="HA11@64_spear_average" src="http://soundexpert.org/documents/10179/776162/dendro_c5_native_spear.png/d8cdbb91-5454-4c96-b68b-2a866dd53ffa?t=1492978315000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA11@64_dcorr_e-link" src="http://soundexpert.org/documents/10179/776162/dendro_c5_native_dcor.png/869b7ec5-dddc-47d0-b718-891774ff3b25?t=1492978315000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA11@64_trmx_spear_average" src="http://soundexpert.org/documents/10179/776162/dendro_c5_trmx_spear.png/b3f0bd56-e7c5-4e62-830f-941fa40f08a0?t=1492978316000" style="width: 249px; height: 300px;" /></td> <td style="text-align: center;"> <img alt="HA11@64_trmx_dcorr_e-link" src="http://soundexpert.org/documents/10179/776162/dendro_c5_trmx_dcor.png/14ef9d81-09e3-47ab-9c14-dcf01ccd1298?t=1492978315000" style="width: 249px; height: 300px;" /></td> </tr> <tr> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> <td style="text-align: center;"> (c)</td> <td style="text-align: center;"> (d)</td> </tr> <tr> <td colspan="2" rowspan="1" style="text-align: center;"> (a)<br /> </td> <td colspan="2" rowspan="1" style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p> </p> <p> According to above clusterization there are no any three codecs which are close enough to perform regression analysis. Apple & Nero and Opus & Vorbis are close though. Tables with distances between all codecs can be found in <a href="http://soundexpert.org/documents/10179/776162/c5_mesurements.txt/cf05f314-c455-413a-9d2f-387b13730303" target="_blank">c5_mesurements.txt</a>. Clusterization with the random mix is quite similar to the one with 30 native samples.</p> <br /> <p style="margin-left: 40px;"> <strong>Table 502</strong>. Average and Max distances within chosen codecs with native audio material and the random mix and two measures of distance: Spearman's rank correlation and Distance correlation.</p> <pre> <span style="font-size:14px;"> Not applicable in this case</span></pre> <p> </p> <h4> 4. Regression analysis.</h4> <p> </p> <p> As the regression analysis is not possible in this case Figure 504 shows Df/Score points without fitting curves.</p> <p> </p> <p style="margin-left: 40px;"> <strong>Table 503</strong>. True and computed quality scores with native audio material (a) and the random mix (b).</p> <pre> <span style="font-size:14px;">Not applicable in this case</span></pre> <p> </p> <p style="margin-left: 40px;"> <strong>Figure 504</strong>. Df/scores scatter plots with native audio material (a) and the random mix (b). All codecs are red as they were not used for computing approximation curves.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td style="text-align: center;"> <img alt="Df/scores scatter plot with native audio material" src="http://soundexpert.org/documents/10179/776162/c5_native_regress.png/a7e9c5ef-23ef-491b-be9a-1e76b1335421?t=1492978314000" style="width: 490px; height: 400px; float: left;" /></td> <td style="text-align: center;"> <img alt="Df/scores scatter plot with the random mix" src="http://soundexpert.org/documents/10179/776162/c5_trmx_regress.png/c821e182-70b7-4035-9cbb-099e88386731?t=1492978315000" style="width: 490px; height: 400px; float: right;" /></td> </tr> <tr> <td style="text-align: center;"> (a)<br /> </td> <td style="text-align: center;"> (b)<br /> </td> </tr> </tbody> </table> <p style="margin-left: 40px;"> </p> <p> <strong>NB!</strong> For Apple and Nero our reciprocal monotonity is broken - higher quality scores correspond to higher Df values in both cases (a) and (b).</p> <p> </p> <h2> <span style="font-size:18px;"><a id="c2c5comb" name="c2c5comb"></a>Analysis of combined HA listening tests' results </span></h2> <p style="text-align: right;"> 2017 Aug 15</p> <p> To the moment we have results of one personal listening test from Kamedo2 and four listening tests from HA Forum. Earlier HA tests are hardly possible to use for the research as they are poorly documented – codecs and samples used in that tests are hard to find. As a consequence, there is no possibility to compute objective degradation of the stimuli signals. For the above mentioned four HA listening tests we collected all necessary info and will try to analyze their results as a whole (23 codecs in total).</p> <p> The purpose of such analysis is to find whether these results support our two main working hypotheses:</p> <p style="margin-left: 40px;"> (1) There is a dependency between degradation of waveform of a stimulus signal and degradation of perceived sound quality of that stimulus signal.<br /> (2) This dependency is more pronounced when type/nature of degradation is similar for tested items.</p> <p> <strong>Note #1</strong>.We measure degradation of waveforms with Difference level (Df, dB), perceived sound quality – with Quality scores (Qs) from listening tests and similarity of degradation – with Spareman's distance between sequences of Df values. Each Df sequence represents piece-wise (400ms) degradation of a stimulus signal and can be considered as a degradation signature of a codec. So, similarity of degradation is similarity between degradation signatures.</p> <p> <strong>Note #2</strong>. Despite common procedure of conducting HA listening tests there are serious differences between them. First, different sound samples and number of them were used during that tests. Second, different listening subjects and number of them participated in the tests (the number of listeners is also varied for different sound samples). These are two main sources of variance for results of our combined analysis.</p> <p> <strong>Note #3</strong>. To keep this analysis simple and easy-to-interpret we will use linear approximation of Qs = f(Df) dependency, thus allowing additional – the third - source of results' variance. In general case a 2nd order curve provides better approximation in least square sense.</p> <p> Scatter plot of 23 codecs tested during the four HA listening tests is in Fig.HA01.</p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Combined results of four HA listening tests" src="http://soundexpert.org/documents/10179/541837/c2-c5_native.png/fccce888-ecbd-487f-b7e9-a39d37013534?t=1502788831000" style="width: 500px; height: 400px;" /></td> <td> <p lang="en-US" style="margin-bottom: 0cm; margin-left: 40px;"> <strong>Figure HA01.</strong> Results of four HA listening tests. Number of codecs tested = 23. The codecs are in Df/Qs space, where Qs stands for Quality score and Df – Difference Level (dB) indicates overall waveform degradation of corresponding sound samples (native) used during the test.</p> </td> </tr> </tbody> </table> <p> </p> <p> Standard practice of testing a dependency is to measure correlation between variables in question (see Note #3). For our 23 points data set correlation coefficient is 0.52. Bootstrapping this coefficient with n=100000 we get estimation of its 95% confidence interval: [-0.78, -0.11]. Fig.HA02 shows distribution of the bootstrapped values. For comparison the figure also shows distribution of correlation coefficient computed using random sampling with replacement of Df values from our data set.</p> <p> </p> <p> <img alt="" src="http://soundexpert.org/documents/10179/541837/c2-c5_df-qs_corr_hist.png/8e63e625-9e57-40b4-9e23-1b48b4bcaf71?t=1502789211000" style="width: 970px; height: 300px;" /></p> <p style="margin-left: 40px;"> <strong>Figure HA02</strong>. Distribution of bootstrapped correlation coefficient. The left histogram is computed using (Df,Qs) values from 23-codec data set; the right histogram is computed using Qs values from 23-codec data set and Df values are randomly sampled with replacement from the data set.</p> <p> </p> <p> Taking into account serious inconsistency of our 23-codec data set (see Note #2), the overlap of two confidence intervals [-0.42, -0.11] doesn't look so dramatic. The supposed dependency between Df and Qs is quite obvious in the figure.<br /> <br /> During our previous separate analyses of HA listening tests (cases 2-5) all participated codecs were used to encode-decode the same Random Mix (in addition to native sound samples). Thus we can measure similarities (distances) between all 23 codecs (see Note #1). Fig.HA03 shows this in the form of dendrogram.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <a href="http://soundexpert.org/documents/10179/541837/c2-c5_dist-spear-average.png/daaa04d6-0d27-4580-9204-f0052b450e85?t=1502789891000" onclick="window.open(this.href, '', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=1236,height=662'); return false;"><img alt="Dendrogram of distances between the codecs" src="http://soundexpert.org/documents/10179/541837/c2-c5_dist-spear-average.png/daaa04d6-0d27-4580-9204-f0052b450e85?t=1502789891000" style="width: 618px; height: 331px;" /></a></td> <td> <p style="margin-left: 40px;"> <strong>Figure HA03</strong>. Dendrogram of distances between the codecs. It shows similarity of the codecs according to the way they degrade the initial waveform of The Random Mix (click the figure to enlarge).</p> </td> </tr> </tbody> </table> <p> <br /> <br /> <br /> <br /> Now we can divide our 23-codec data set into n-codec subsets and compute for each subset average distance between codecs and RMS error of their linear approximation. Resulting scatter plots of the subsets for n=4|5|6 are on Fig.HA04.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="All possible 4-codec subsets of the 23-codec data set" src="http://soundexpert.org/documents/10179/541837/c2-c5_dist-err_4codec.png/0435a351-2a2e-4d00-8a35-492b9a794642?t=1502790349000" style="width: 493px; height: 400px;" /></td> <td> <img alt="All possible 5-codec subsets of the 23-codec data set" src="http://soundexpert.org/documents/10179/541837/c2-c5_dist-err_5codec.png/249f71b5-4245-4628-8caf-57d354946ea7?t=1502790393000" style="width: 493px; height: 400px;" /></td> </tr> <tr> <td style="vertical-align: top;"> <p> </p> <p> <strong>Figure HA04</strong>. All possible n-codec subsets of the 23-codec data set. For each subset the two parameters were computed – similarity between codecs in subset (Average distance) and RMS error of their linear approximation. The subsets with “wrong” angle of their linear approximation (quality increases with increase of Df levels) are red.</p> </td> <td> <img alt="All possible 6-codec subsets of the 23-codec data set" src="http://soundexpert.org/documents/10179/541837/c2-c5_dist-err_6codec.png/08075ba3-db59-42cc-b995-7d25c56e9d55?t=1502790428000" style="width: 493px; height: 400px;" /></td> </tr> </tbody> </table> <p> </p> <p> Computing distances between codecs with The Random Mix, not the native sound material used in the listening tests, additionally increases variance of RMS errors on the scatter plots (the fourth source of variance). As a result the plots look messy. But even on such imperfect plots the positive trend is quite discernible while “wrong” approximations (in red) are substantially less in quantity and drop out of the trend. In other words, even such inconsistent data support our second hypothesis – the better similarity between codecs, the lower errors of their fit to Df/Qs curve (linear in this particular case). Exactly this relationship between similarity of waveform degradations and goodness of fit of Df and Qs values to some psychometric curve has the highest practical value as it helps to determine in what cases listening tests can be safely substituted with objective measurements. Unfortunately the data from HA listening tests are suitable only for qualitative estimation of that dependency. Quantitative estimations are possible only with more consistent data, which can be obtained from properly organized listening test with multiple testing items or series of proper tests with the same panel of listening experts and the same set of sound samples.</p> <p> </p> <p> to be continued ...</p> <p> </p>Serge Smirnoff2015-11-02T07:05:00ZAudio quality of iPhone 6Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-iphone-62018-10-25T19:53:57Z2015-07-07T10:27:00Z<div class="portlet-msg-info"> This article is obsolete and retained for archival purpose. Listening tests of portable players are no-longer performed and substituted by objective measurements which are available on portable players page - <a href="http://soundexpert.org/portable-players">http://soundexpert.org/portable-players</a>. The measurements of iPhone 6 can be found here - <a href="http://soundexpert.org/portable-players-beta">http://soundexpert.org/portable-players-beta</a></div> <p> Four years ago SE started sound quality evaluation of portable media players. Results collected for the first few contenders showed that testing procedure has some serious drawbacks and needs to be corrected. For example, using real headphones as a load (and especially Koss Porta Pro) leads to specific coloring of sound for players with higher output impedance. Also, recent research related to diffrograms revealed that test files for analog audio devices can be and must be processed with higher accuracy. And finally, objective measurements of analog circuits have sense. New method of objective testing, based on Difference level parameter, helps to discover problem signals and to evaluate waveform degradation of real-life sound material for any device under test. So, results of such testing in addition to usual SE listening tests would be helpful.</p> <p> Taking all this into account it was decided to start testing of portable media players afresh. Previous results will be discarded, sorry.</p> <p> The first contender for this enhanced testing is iPhone 6. Results of its objective measurements are summarized in compact form - df-slide, shown in Fig.1. All df-slides for portable players which were tested at SoundExpert are collected on this page - <a href="http://soundexpert.org/portable-players-beta">http://soundexpert.org/portable-players-beta</a></p> <p> </p> <p> <img alt="Results of testing iPhone 6" src="http://soundexpert.org/documents/10179/272881/iPhone6%40SoundExpert.png/00b7da19-3b4e-4feb-9e76-396cfdd4c2d2?t=1436266571000" style="width: 1000px; height: 311px;" /><br /> <strong>Figure 1</strong>. Results of testing media player of iPhone 6 with various audio signals and single measurement approach based on Difference level parameter.</p> <p> </p> <p> The diagram shows how various signals (including real-life ones) are distorted when they are played back by iPhone 6. We can safely conclude that:</p> <ul> <li> pure sine waves both 1kHz and 12.5kHz have low levels of distortion (-79.0dB and -78.9dB)</li> <li> inter-modulation distortion is pretty high (the sum of sine waves 12460Hz and 12540Hz at the output of iPhone 6 has substantially higher level of difference with initial waveform: -45.9dB)</li> <li> serious gap between accuracy of reproduction of triangle and square waves (-38.7dB and -16.3dB) means that iPhone 6 has phase distortion; signals with multiple frequency components are affected the most (white noise -4.6dB)</li> <li> median of 6430 Df values (the whole Pink Floyd album divided into 400ms pieces) sums up all possible types of distortion of the real-life audio signal; the value (-25.7dB) is pretty close to degradation of Program Simulation Noise (-24.9dB); this is very promising and even a bit surprising; level of degradation of this signal could be a single integral and informative objective indicator which says a lot about performance of a device under test; more audio devices should be tested in order to make more confident conclusions about usefulness of such indicator.</li> </ul> <p> Other test signals could be synthesized and used for discovering various aspects of an audio device performance. As the measurement procedure is the same for all signals, their values of degradation can be compared with each other directly; the whole audio metric becomes connected.</p> <p> Feel free to share and discuss the above diagram.</p> <p> SoundExpert thanks Rasim for allowing to test his iPhone 6.</p> <p style="text-align: center;"> <span style="font-size:18px;">***</span></p> <p class="se-message"> SoundExpert reminds you that final conclusion about audio quality of any device added can be made only after finishing corresponding listening test. So we encourage you to take part in testing. SE ratings exist only thanks to visitors like you. Testing is short and easy, visit our <a href="http://soundexpert.org/testing-room">Testing Room</a> for simple 1-2-3 instruction.<br /> <br /> Please, remember, downloading test files from SoundExpert you will not necessarily get the ones of the newly added devices or codecs. SoundExpert testing is blind testing – you don't know the device you test. This is the only reliable way of getting true audio quality ratings, free from any cheating and various human senses other than perception of sound quality. After you have sent your grade you will see the device you tested.</p> <p> Best regards,<br /> SE Team.</p> <p> </p> <hr /> <p style="text-align: right;"> <strong>Update 2015 Aug 26</strong></p> <p> After adoption of final set of test signals (<a href="http://soundexpert.org/test-signals">http://soundexpert.org/test-signals</a>) it was decided to test iPhone 6 once again. Results are below.</p> <p> </p> <p> <img alt="Testing iPhone 6 with final set of test signals" src="http://soundexpert.org/documents/10179/272881/iPhone6%40SoundExpertV2.png/bb3922c4-0d4c-40ab-aa91-cd2fc37f98a7?t=1440585451000" style="width: 1000px; height: 311px;" /><br /> <strong>Figure 2</strong>. Results of testing media player of iPhone 6 with final set of test signals and single measurement approach based on Difference level parameter.</p> <p> </p> <p> What changed:</p> <ul> <li> <em>triangular</em> and <em>square</em> waves are band-limited now, so they are reproduced with higher accuracy (lower Df values) by device under test</li> <li> triangular (even) signal is added (ass train); comparing its degradation with the standard triangular (odd) wave we can conclude that <em>even</em> harmonics slightly prevail over <em>odd</em> ones at the output of iPhone 6.</li> </ul> <p> SE thanks Olesya for allowing to test her iPhone 6.</p> <p> Best regards,<br /> SE Team.</p> <p> </p>Serge Smirnoff2015-07-07T10:27:00ZOpus at high bitrates (128-192-256 kbit/s)Serge Smirnoffhttp://soundexpert.org/articles/-/blogs/opus-at-high-bitrates-128-192-256-kbit-s-2015-03-19T16:07:08Z2015-03-19T15:20:00Z<p> It looks like Opus audio format becomes popular. During last month SE received several requests to add it to the rating system. Low bitrate settings (--bitrate 59-90-96) were in the system since the first public release of the codec. Now high bitrates (--bitrate 128-192-256) are added as well.</p> <p> In contrast to other VBR encoders Opus uses “non-standard” bit allocation strategy for different audio material. As a consequence encoding of less saturated music (with fewer instruments) can result in higher output bitrates than encoding of pop music for example. The table below shows that. Two different music fragments – pop-rock and classic – were encoded to Opus and mp3 formats with approximately equal VBR settings. While mp3 encoder shows usual behavior allocating more bits for more complex pop-rock material, Opus behaves exactly the opposite.</p> <p> </p> <table border="1" cellpadding="1" cellspacing="1" style="width: 100%;"> <tbody> <tr> <td colspan="1" rowspan="2" style="text-align: center;"> </td> <td colspan="3" style="text-align: center; width: 40%;"> mp3 (kbit/s)</td> <td colspan="3" style="text-align: center; width: 40%;"> Opus (kbit/s)</td> </tr> <tr> <td style="text-align: center;"> -V5</td> <td style="text-align: center;"> -V2</td> <td style="text-align: center;"> -V0</td> <td style="text-align: center;"> --bitrate 128</td> <td style="text-align: center;"> --bitrate 192</td> <td style="text-align: center;"> --bitrate 256</td> </tr> <tr> <td style="text-align: center;"> Pop-Rock</td> <td style="text-align: center;"> 126.6</td> <td style="text-align: center;"> 187.3</td> <td style="text-align: center;"> 260.6</td> <td style="text-align: center;"> 126.5</td> <td style="text-align: center;"> 190.4</td> <td style="text-align: center;"> 255.1</td> </tr> <tr> <td style="text-align: center;"> Classic</td> <td style="text-align: center;"> 106.9</td> <td style="text-align: center;"> 176.3</td> <td style="text-align: center;"> 231.2</td> <td style="text-align: center;"> 151.7</td> <td style="text-align: center;"> 216.8</td> <td style="text-align: center;"> 278.1</td> </tr> </tbody> </table> <p> <strong>Table 1</strong>. Resulting bitrates of encoding pop-rock music (Midnight Oil - (1996) Breathe, tracks 7-13, 26:53) and classic music (Piazzolla and Kronos Quartett - (1991) Five Tango Sensations, 26:50) with mp3 (Lame 3.99.5) and Opus (libopus 1.1) encoders at 128-192-256 kbit/s VBR settings. Opus encoder ends up with higher bitrates for less complex music.</p> <p> </p> <p> Nine SE testing samples are usually encoded with lower bitrates by all modern VBR encoders because most samples are pure voices or instruments. Opus is the only encoder which produced actual bitrates higher than the set ones: 152.3kbit/s for 128kbit/s, 222.5kbit/s for 192kbit/s and 290.1kbit/s for 256kbit/s. So the ratings of Opus were placed on 160kbit/s, 224kbit/s and 320+kbit/s pages respectively. This is less convenient but more correct as all SE ratings are grouped according to actual bitrates.</p> <p> The encoder operates at 48kHz only, so for other sample rates (as in our case) resampling is required. Some good quality resampler is already integrated into the codec but we used the external one from Audition CS6. The complete test files production chain is as follows:</p> <p> reference test files 44.1/16 -->> 48/24(Audition CS6) -->> opusenc -->> decode by foobar2000(48/32) -->> 44.1/32(Audition CS6) -->> test files production</p> <p> Opus encoder/decoder can be downloaded <a href="http://from http://opus-codec.org/downloads/" target="_blank">from http://opus-codec.org/downloads/</a><br /> </p> <p id="aui_3_4_0_1_1178" style="text-align: center;"> <span id="aui_3_4_0_1_1177" style="font-size:18px;">***</span></p> <p class="se-message"> SoundExpert reminds you that final conclusion about audio quality of any device added can be made only after finishing corresponding listening test. So we encourage you to take part in testing. SE ratings exist only thanks to visitors like you. Testing is short and easy, visit our <a href="http://soundexpert.org/testing-room">Testing Room</a> for simple 1-2-3 instruction.<br /> <br /> Please, remember, downloading test files from SoundExpert you will not necessarily get the ones of the newly added codecs. SoundExpert testing is blind testing – you don't know the device you test. This is the only reliable way of getting true audio quality ratings, free from any cheating and various human senses other than perception of sound quality. After you have sent your grade you will see the device you tested.</p> <p> Best regards,<br /> SE Team.</p>Serge Smirnoff2015-03-19T15:20:00ZDiffrogram: visualization of signal differences in audio researchSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/visualization-of-distortion2023-09-20T15:13:13Z2014-09-10T09:25:00Z<h2 style="text-align: right;"> <strong>Part 1</strong></h2> <p style="text-align: right;"> Draft. 2014 Sep 10. Live research.</p> <p> </p> <p> From the early days of SoundExpert the objective audio parameter – signal difference level (<em>Df</em>) – was actively used for audio research within the project. This simple parameter shows difference between a reference (input) waveform and a processed (output) one. It is defined as follows:</p> <p style="text-align: center;"> <em>Df [%] = (1 - |p|) * 100</em> or <em>Df [dB] = 10 * Log10(1 - |p|)</em>, where <em>p</em> is correlation coefficient.</p> <p> When signals' waveforms are identical, <em>Df = -Infinity [dB]</em>; when the forms are completely different, <em>Df = 0 [dB];</em> levels and DC offsets of both signals do not affect difference level. The main beauty of the parameter is that it can be used with signals of any shape, both synthetic (sine, white noise, …) and real-life (music, voice, ...). So, in order to evaluate some device under test you can feed it with various signals and measure degradation of those signals with one and the same parameter. For sinusoidal signals <em>Df[dB]</em> approximately equals to <em>(THD – 3.01)</em>.</p> <p> <em>Df</em> can be computed for any signal of any duration, for a whole signal or for any part of it. Usual time blocks of 50+ ms (<em>Tb</em>) are very suitable for <em>Df</em> calculation. To visualize <em>Df</em> values throughout a signal they can be color coded, showing distortion of different signal sections. Example of such diffrogram is shown in Fig.1.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of glockenspiel sample played back by iPhone 5s" src="http://soundexpert.org/documents/10179/130750/iPhone5s_GLK_mono_50_nospectr.png/ba1c397f-18f3-4d50-8fa6-890dd3031ac8?t=1410342961000" style="width: 306px; height: 100px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Fig.1.</strong> Diffrogram of glockenspiel sample played back by iPhone 5s. Each 1 pixel bar represents 50 ms (<em>Tb</em>) of the signal. Green areas correspond to lower distortion (lower <em>Df</em> values, closer to <em>-Inf</em> [dB]), red ones correspond to higher degradation of initial waveform of the sample. Mean <em>Df</em> of all time blocks is -27.7 dB.<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = -27.7 dB</p> </td> </tr> </tbody> </table> <p> </p> <p> Diffrogram becomes more revealing when combined with spectrogram. As color is already used for <em>Df</em> visualization, amplitude of spectral components can be coded with lightness/darkness of color. Fig.2 shows such enhanced diffrogram from the previous example.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram combined with spectrogram of glockenspiel sample played back by iPhone 5s" src="http://soundexpert.org/documents/10179/130750/iPhone5s_GLK_mono_50.png/d048eef3-7f85-42d6-9638-64158702615e?t=1410342975000" style="width: 347px; height: 113px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Fig.2.</strong> Diffrogram from Fig.1 combined with spectrogram. Hue of color represents difference level, lightness/darkness of color represents amplitude of frequency components.<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = -27.7 dB</p> </td> </tr> </tbody> </table> <p> </p> <p> Color map of (difference level, amplitude) space is shown in Fig.3.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Two-dimensional color map used in diffrograms for visualization" src="http://soundexpert.org/documents/10179/130750/df-a_colormap.png/02041df1-e7b9-4f6d-b344-82487369792b?t=1410353660000" style="width: 247px; height: 242px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Fig.3.</strong> Two-dimensional color map used in diffrograms for visualization of difference levels and amplitudes of frequency components. Method of building isoluminant color scale is taken from the paper <a href="http://www.cs.utah.edu/~gk/papers/vis02/" target="_blank">"Face-based Luminance Matching for Perceptual Colormap Generation" by Gordon Kindlmann, Erik Reinhard, Sarah Creem</a>.</p> </td> </tr> </tbody> </table> <p> </p> <p> Below are some trivial examples with sinusoidal signals which help to understand diffrograms better and which show the accuracy of <em>Df</em> computation. First set of examples are sine signals (1 kHz, 10 sec) of three different levels (-3dBFS, -9dBFS, -27dBFS) quantized (without dithering) from 32bit(float) to 24bit and 16bit:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="sine 1kHz, -3dBFS, 24 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-3_24_100-144.7.png/7a36cb51-2a91-4fbf-beb2-39f4b1ebd2b7?t=1410360524000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -3dBFS, 32bit<br /> OUT: sine 1kHz, -3dBFS, 24 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-144.7 dB</strong></td> <td> <img alt="sine 1kHz, -9dBFS, 24 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-9_24_100-140.4.png/34075426-9985-4c92-b690-5f1f6bee8492?t=1410360525000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -9dBFS, 32 bit<br /> OUT: sine 1kHz, -9dBFS, 24 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-140.4 dB</strong></td> <td> <img alt="sine 1kHz, -27dBFS, 24 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-27_24_100-122.3.png/e4543f0d-dcb8-4b87-ae9a-90390e48a488?t=1410360525000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -27dBFS, 32 bit<br /> OUT: sine 1kHz, -27dBFS, 24 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-122.3 dB</strong></td> </tr> <tr> <td colspan="6"> </td> </tr> <tr> <td> <img alt="sine 1kHz, -3dBFS, 16 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-3_16_100-97.9.png/03ca0eea-97db-43a6-a013-8041986e6d10?t=1410360524000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -3dBFS, 32 bit<br /> OUT: sine 1kHz, -3dBFS, 16 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-97.9 dB</strong></td> <td> <img alt="sine 1kHz, -9dBFS, 16 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-9_16_100-92.2.png/b59512d3-2c5c-4c59-bd20-2648948c6f24?t=1410360525000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -9dBFS, 32 bit<br /> OUT: sine 1kHz, -9dBFS, 16 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-92.2 dB</strong></td> <td> <img alt="sine 1kHz, -27dBFS, 16 bit" src="http://soundexpert.org/documents/10179/130750/sin1k-27_16_100-73.8.png/6ca783ef-b95c-4129-9864-ec7dddbade4d?t=1410360525000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1kHz, -27dBFS, 32 bit<br /> OUT: sine 1kHz, -27dBFS, 16 bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-73.8 dB</strong></td> </tr> <tr> <td colspan="6"> <br /> <strong>Fig.4.</strong> Diffrograms of sinusoidal signals of different levels, quantized from 32bit(float) to 24bit and 16bit. Quantization errors are higher at lower levels.</td> </tr> </tbody> </table> <p> </p> <p> Signals of lower levels are subject to higher levels of degradation (quantization errors) and this is indicated by color. Non-uniform color on -3dBFS/24bit diffrogram reflects computational errors of extremely low <em>Df</em> values. Thus, difference level -140 dB could be considered as maximum accuracy of <em>Df</em> computation using current algorithm.</p> <p> Accuracy of <em>Df</em> measurement is affected not only by computational error. Even slightest time misalignment of input and output signals makes calculation of <em>Df</em> impossible. While digital processing of signals is usually time accurate, conversion from digital to analog and vice versa is not. All analog signals must be precisely time warped before computing of <em>Df</em>. The next set of examples shows accuracy of this part of measurement procedure. Once again, sinusoidal signals are very appropriate for the case as they can be easily generated in digital form with any parameters and the shapes of all sine waves are perfectly identical by definition. In the following set of examples <em>Df</em> values were computed with sine signals of slightly deviated frequencies. As our time warping procedure is sensitive to sampling rate of a signal, <em>Df</em> values were computed for five different frequencies (1, 5, 10, 15, 20 [kHz]) and four sampling rates (44101, 96002, 192004, 384009 [Hz]).</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="sine 1k(44101)" src="http://soundexpert.org/documents/10179/130750/sin1k-3%2844%2B%29_100-143.5.png/8ae48092-e9ba-4cf9-9033-abae9f4128d1?t=1410370457000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1k(44100)<br /> OUT: sine 1k(44101)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-143.5 dB</strong></td> <td> <img alt="sine 1k(96002)" src="http://soundexpert.org/documents/10179/130750/sin1k-3%2896%2B%29_100-145.5.png/7fba84c5-861e-45f2-a206-747d584712bc?t=1410370457000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1k(44100)<br /> OUT: sine 1k(96002)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-145.5 dB</strong></td> <td> <img alt="sine 1k(192004)" src="http://soundexpert.org/documents/10179/130750/sin1k-3%28192%2B%29_100-143.6.png/451078a2-e6c3-4791-a9dd-9c86ea06da59?t=1410370457000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 1k(44100)<br /> OUT: sine 1k(192004)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-143.6 dB</strong></td> <td> </td> <td> </td> </tr> <tr> <td colspan="8"> </td> </tr> <tr> <td> <img alt="sine 5k(44101)" src="http://soundexpert.org/documents/10179/130750/sin5k-3%2844%2B%29_100-82.7.png/53d15ffb-4fab-4af4-975f-94091028e4c7?t=1410370457000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 5k(44100)<br /> OUT: sine 5k(44101)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-82.7 dB</strong></td> <td> <img alt="sine 5k(96002)" src="http://soundexpert.org/documents/10179/130750/sin5k-3%2896%2B%29_100-102.2.png/defe9d42-693d-45fc-b93e-655d3275f9c2?t=1410370458000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 5k(44100)<br /> OUT: sine 5k(96002)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-102.2 dB</strong></td> <td> <img alt="sine 5k(192004)" src="http://soundexpert.org/documents/10179/130750/sin5k-3%28192%2B%29_100-126.5.png/546c20af-f7fd-41eb-95a6-8de3ba637e87?t=1410370458000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 5k(44100)<br /> OUT: sine 5k(192004)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-126.5 dB</strong></td> <td> </td> <td> </td> </tr> <tr> <td colspan="8"> </td> </tr> <tr> <td> <img alt="sine 10k(44101)" src="http://soundexpert.org/documents/10179/130750/sin10k-3%2844%2B%29_100-51.4.png/5de475e0-25d0-4980-8765-b37d528a242f?t=1410370458000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 10k(44100)<br /> OUT: sine 10k(44101)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-51.4 dB</strong></td> <td> <img alt="sine 10k(96002)" src="http://soundexpert.org/documents/10179/130750/sin10k-3%2896%2B%29_100-76.6.png/cd1e4d68-75bf-49d3-b196-fe4ef8a6fc57?t=1410370459000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 10k(44100)<br /> OUT: sine 10k(96002)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-76.6 dB</strong></td> <td> <img alt="sine 10k(192004)" src="http://soundexpert.org/documents/10179/130750/sin10k-3%28192%2B%29_100-101.5.png/1e904b26-9924-4dd5-a155-d9104969609b?t=1410370459000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 10k(44100)<br /> OUT: sine 10k(192004)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-101.5 dB</strong></td> <td> </td> <td> </td> </tr> <tr> <td colspan="8"> </td> </tr> <tr> <td> <img alt="sine 15k(44101)" src="http://soundexpert.org/documents/10179/130750/sin15k-3%2844%2B%29_100-30.9.png/6c630ee7-2a5a-47a2-86f2-41d99deee008?t=1410370460000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 15k(44100)<br /> OUT: sine 15k(44101)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-30.9 dB</strong></td> <td> <img alt="sine 15k(96002)" src="http://soundexpert.org/documents/10179/130750/sin15k-3%2896%2B%29_100-61.0.png/c3b1244a-b219-405b-a5af-47822633fbc9?t=1410370460000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 15k(44100)<br /> OUT: sine 15k(96002)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-61.0 dB</strong></td> <td> <img alt="sine 15k(192004)" src="http://soundexpert.org/documents/10179/130750/sin15k-3%28192%2B%29_100-87.1.png/5852f78a-13ee-4909-b4fa-57f6abfff11e?t=1410370461000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 15k(44100)<br /> OUT: sine 15k(192004)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-87.1 dB</strong></td> <td> </td> <td> </td> </tr> <tr> <td colspan="8"> </td> </tr> <tr> <td> <img alt="sine 20k(44101)" src="http://soundexpert.org/documents/10179/130750/sin20k-3%2844%2B%29_100-13.9.png/ad4fd395-5016-4d73-aa92-a9987e028398?t=1410370461000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 20k(44100)<br /> OUT: sine 20k(44101)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-13.9 dB</strong></td> <td> <img alt="sine 20k(96002)" src="http://soundexpert.org/documents/10179/130750/sin20k-3%2896%2B%29_100-49.1.png/823fc1ef-2908-4a18-8393-f5731552f727?t=1410370461000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 20k(44100)<br /> OUT: sine 20k(96002)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-49.1 dB</strong></td> <td> <img alt="sine 20k(192004)" src="http://soundexpert.org/documents/10179/130750/sin20k-3%28192%2B%29_100-76.6.png/5baaa9f3-0cae-45f5-9db8-63daffd346aa?t=1410370462000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 20k(44100)<br /> OUT: sine 20k(192004)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-76.6 dB</strong></td> <td> <img alt="sine 20k(384009)" src="http://soundexpert.org/documents/10179/130750/sin20k-3%28384%2B%29_100-102.2.png/a7f52432-3234-46ee-93c1-d15dca730a5f?t=1410370462000" style="width: 100px; height: 100px;" /></td> <td> REF: sine 20k(44100)<br /> OUT: sine 20k(384009)<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-102.2 dB</strong></td> </tr> <tr> <td colspan="8"> <br /> <strong>Fig.5.</strong> Diffrogramms of sinusoidal signals (-3dBFS, 10sec) of slightly deviated frequencies. They show accuracy of time warping algorithm at different sampling rates.</td> </tr> </tbody> </table> <p> </p> <p> As all sine waveforms are identical, the above diffrograms show accuracy of time warping procedure. According to the figure max. accuracy of time warping of frequencies around 20k at 384k sampling rate is -102 dB. So, calculation of difference levels below -100 dB for full bandwidth analog signals (which always require time warping) should be done at 10x sampling rate or higher.</p> <p> Now we are ready to compute diffrograms for some real life audio signals. Figure 6 shows diffrograms of glockenspiel sample quantized from 32bit(float) to 24bit and 16bit. Figure 7 shows this sample up-sampled from 44100 to 96000 Hz in Adobe Audition and in foobar2000; both using max. quality settings.</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="GLK 24bit (44100)" src="http://soundexpert.org/documents/10179/130750/GLK%2844%29_24_mono_50-114.8.png/d2b998bd-21f6-4744-b253-e6e8072f5f84?t=1410383928000" style="width: 305px; height: 100px;" /></td> <td> REF: GLK 32bit (44100)<br /> OUT: GLK 24bit (44100)<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = <strong>-114.8 dB</strong></td> <td> <img alt="GLK 32bit (96000, AA)" src="http://soundexpert.org/documents/10179/130750/GLK%2896a%29_mono_50-84.5.png/1b00131b-0d98-41a2-9234-da92736dc7de?t=1410383928000" style="width: 305px; height: 100px;" /></td> <td> REF: GLK 32bit (44100)<br /> OUT: GLK 32bit (96000, AA)<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = <strong>-84.5 dB</strong></td> </tr> <tr> <td colspan="4"> </td> </tr> <tr> <td> <img alt="GLK 16bit (44100)" src="http://soundexpert.org/documents/10179/130750/GLK%2844%29_16_mono_50-67.5.png/bfa38db7-f5bd-4046-93f3-3ded945e8eb3?t=1410383928000" style="width: 305px; height: 100px;" /></td> <td> REF: GLK 32bit (44100)<br /> OUT: GLK 16bit (44100)<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = <strong>-67.5 dB</strong></td> <td> <img alt="GLK 32bit (96000, fb)" src="http://soundexpert.org/documents/10179/130750/GLK%2896f%29_mono_50-74.3.png/4ddff56a-61f4-477b-ad30-f5341d336c6b?t=1410383928000" style="width: 305px; height: 100px;" /></td> <td> REF: GLK 32bit (44100)<br /> OUT: GLK 32bit (96000, fb)<br /> <em>Tb</em> = 50 ms<br /> <em>Df</em> = <strong>-74.3 dB</strong></td> </tr> <tr> <td colspan="2"> <br /> <strong>Fig.6.</strong> Diffrograms of glockenspiel sample quantized from 32bit(float)<br /> to 24bit and 16bit.</td> <td colspan="2"> <br /> <strong>Fig.7.</strong> Diffrograms of glockenspiel sample up-sampled from 44100Hz to 96000Hz<br /> in Adobe Audition CS6 (AA) and foobar2000 v1.3.3 (fb).</td> </tr> </tbody> </table> <p> </p> <p> Even taking into account inaccuracy of time warping of high frequencies at 96000 sampling rate we can safely conclude from fig.7 that up-sampling in Audition CS6 preserves initial (reference) waveform better than upsampling in foobar2000 - mean <em>Df</em> values and colors are quite indicative.</p> <p> The next set of diffrograms could be considered as real-life application of this new audio metric. We'll use it for evaluation of three portable devices:</p> <ul> <li> <strong>FiiO E17</strong> - USB DAC headphone amplifier</li> <li> <strong>iPhone 5s</strong> - smartphone</li> <li> <strong>iPhone 6</strong> - smartphone</li> <li> <strong>iriver E100</strong> - multimedia player</li> </ul> <p> Sinusoidal signal (1kHz, -15dBFS, 44100Hz, 16bit, 20sec), white noise (-15dBFS, 44100Hz, 16bit, 20sec) and nine SE test samples (44100Hz, 16bit) were played back on these devices (left channel only) at matched levels and recorded from headphone outputs (loaded with 33Ohm resistors) with MicroTrack at 96k/24bit.</p> <p> Below are diffrograms of these three portable devices and the above signals:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="FiiO E17, 96000Hz, 24bit, sine" src="http://soundexpert.org/documents/10179/130750/fiioE17_sine_100-72.3.png/98378095-fa64-48d7-9067-d690dc669958?t=1410423585000" style="width: 200px; height: 100px;" /></td> <td> REF: sine 1k, 44100Hz, 16bit<br /> OUT: FiiO E17, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-72.3 dB</strong></td> <td> <img alt="FiiO E17, 96000Hz, 24bit, white noise" src="http://soundexpert.org/documents/10179/130750/fiioE17_wnoise_100-29.5.png/2095ce9b-589f-41bf-a805-22f50aae7ad1?t=1410423585000" style="width: 200px; height: 100px;" /></td> <td> REF: white noise, 44100Hz, 16bit<br /> OUT: FiiO E17, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-29.5 dB</strong></td> </tr> <tr> <td colspan="4"> </td> </tr> <tr> <td> <img alt="iPhone 5s, 96000Hz, 24bit, sine" src="http://soundexpert.org/documents/10179/130750/iPhone5S_sine_100-70.5.png/6548c702-22ef-45ce-8c68-d030714ba124?t=1410423586000" style="width: 200px; height: 100px;" /></td> <td> REF: sine 1k, 44100Hz, 16bit<br /> OUT: iPhone 5s, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-70.5 dB</strong></td> <td> <img alt="iPhone5s, 96000Hz, 24bit, white noise" src="http://soundexpert.org/documents/10179/130750/iPhone5S_wnoise_100-4.5.png/d759db3c-73d1-46e6-9cf5-7bc9192fa909?t=1410423586000" style="width: 200px; height: 100px;" /></td> <td> REF: white noise, 44100Hz, 16bit<br /> OUT: iPhone 5s, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-4.5 dB</strong></td> </tr> <tr> <td colspan="4"> </td> </tr> <tr> <td> <img alt="iPhone 6, 96000Hz, 24bit, sine" src="http://soundexpert.org/documents/10179/130750/iPhone6_sine_100-70.6.png/e58dbb38-555d-4df2-abf0-293ec4c08025?t=1412616656000" style="width: 200px; height: 100px;" /></td> <td> REF: sine 1k, 44100Hz, 16bit<br /> OUT: iPhone 6, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-70.6 dB</strong></td> <td> <img alt="iPhone 6, 96000Hz, 24bit, white noise" src="http://soundexpert.org/documents/10179/130750/iPhone6_wnoise_100-4.6.png/dd1ce4b0-beaf-4325-83bf-9f7b51fff486?t=1412616792000" style="width: 200px; height: 100px;" /></td> <td> REF: white noise, 44100Hz, 16bit<br /> OUT: iPhone 6, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-4.6 dB</strong></td> </tr> <tr> <td colspan="4"> </td> </tr> <tr> <td> <img alt="iriver E100, 96000Hz, 24bit, sine" src="http://soundexpert.org/documents/10179/130750/iriverE100_sine_100-70.6.png/a8acd934-59a9-4b60-819d-75ac39aed321?t=1410423587000" style="width: 200px; height: 100px;" /></td> <td> REF: sine 1k, 44100Hz, 16bit<br /> OUT: iriver E100, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-70.6 dB</strong></td> <td> <img alt="iriver E100, 96000Hz, 24bit, white noise" src="http://soundexpert.org/documents/10179/130750/iriverE100_wnoise_100-18.0.png/7784f0d7-c602-4fba-96f1-d6df32fa679e?t=1410423588000" style="width: 200px; height: 100px;" /></td> <td> REF: white noise, 44100Hz, 16bit<br /> OUT: iriver E100, 96000Hz, 24bit<br /> <em>Tb</em> = 100 ms<br /> <em>Df</em> = <strong>-18.0 dB</strong></td> </tr> <tr> <td colspan="2" rowspan="1"> <br /> <strong>Fig.8.</strong> Diffrograms of FiiO E17, iPhone 5s, iPhone 6 and iriver E100<br /> with sinusoidal signal.</td> <td colspan="2" rowspan="1"> <br /> <strong>Fig.9.</strong> Diffrograms of FiiO E17, iPhone 5s, iPhone 6 and iriver E100<br /> with white noise signal.</td> </tr> </tbody> </table> <p> </p> <p> While all three devices show almost similar performance with sine signal, white noise reveals significant distinctions in its reproduction. These distinctions are also evident on diffrograms of these devices with <a href="http://soundexpert.org/sound-samples">nine SE samples</a>:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="FiiO E17, 96000Hz, 24bit, SE samples" src="http://soundexpert.org/documents/10179/130750/fiioE17_left_100-26.6.png/f2e15db9-a84e-4916-8695-ce07866ec47b?t=1412616274838" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: FiiO E17, 96000Hz, 24bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-26.6 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="iPhone5s, 96000Hz, 24bit, SE samples" src="http://soundexpert.org/documents/10179/130750/iPhone5s_left_100-24.6.png/487a9ec7-eee9-446f-9c66-b92dea4f916a?t=1412616374600" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: iPhone 5s, 96000Hz, 24bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-24.6 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="iPhone6, 96000Hz, 24bit, SE samples" src="http://soundexpert.org/documents/10179/130750/iPhone6_left_100-24.4.png/d0cea66a-4b78-4fd6-bc6e-b8cd070df4a2?t=1412616655000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: iPhone 6, 96000Hz, 24bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-24.4 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="iriver E100, 96000Hz, 24bit, SE samples" src="http://soundexpert.org/documents/10179/130750/iriverE100_left_100-16.7.png/a29f2ac3-f30d-4c3b-a9cc-7deb5bc7b0f9?t=1412616479289" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: iriver E100, 96000Hz, 24bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-16.7 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <strong>Fig.10.</strong> Diffrograms of FiiO E17, iPhone 5s, iPhone 6 and iriver E100 with nine SE samples.</td> </tr> </tbody> </table> <p> </p> <p> At this point we are not trying to explain distinctions on these diffrograms and their impact on perceived audio quality of the devices. We can just establish the fact that various signals are transferred through these devices with various precision. In order to show that the relationship between objectively measured signal difference level and subjective perception of sound quality is not trivial (as well as for the purpose of some soft scientific trolling), here is a set of diffrograms of Lame (3.99.5) mp3 encoder at different quality settings (-V) with the nine SE samples:</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0" style="width: 100%;"> <tbody> <tr> <td> <img alt="Lame -b 320, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lame320_mono_100-48.3.png/76577762-635c-4646-a4b2-6f712e506900?t=1410436878000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-b 320</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-48.3 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V0, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV0_mono_100-40.8.png/8281ce61-8041-4bf2-8dd8-d9ec6fcf5e41?t=1410436878000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V0</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-40.8 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V1, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV1_mono_100-38.3.png/a3fa57d3-fe70-4cb8-9b81-d1192efffaa3?t=1410436878000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V1</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-38.3 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V2, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV2_mono_100-35.9.png/ac88e85f-2a4d-4130-86b3-03313fb68c65?t=1410436879000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V2</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-35.9 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V3, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV3_mono_100-34.5.png/4dafb875-c99d-425c-b799-53946d68bccb?t=1410436879000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V3</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-34.5 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V4, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV4_mono_100-32.4.png/0b0c9d34-f844-4c0b-ac7c-4e1a15588831?t=1410436879000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V4</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-32.4 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V5, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV5_mono_100-29.1.png/902335a5-03a7-4fa4-997d-c0fef84da880?t=1410436880000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V5</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-29.1 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V6, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV6_mono_100-26.4.png/960cfdb9-4ded-42db-9774-926678cb183c?t=1410436880000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V6</span>, 44100Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-26.4 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V7, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV7_mono_100-25.4.png/430c5a2f-3c28-4c9b-8100-efb32bc57e9b?t=1410436881000" style="width: 931px; height: 114px;" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V7</span>, 32000Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-25.4 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V8, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV8_mono_100-26.9.png/8501981d-dca0-43f8-ac58-73d107538899?t=1410436881000" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V8</span>, 24000Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-26.9 dB</strong></td> </tr> <tr> <td> </td> </tr> <tr> <td> <img alt="Lame -V9, 44100Hz, 32bit, SE samples" src="http://soundexpert.org/documents/10179/130750/lameV9_mono_100-24.5.png/b9433334-99d4-4722-821d-c961969013bb?t=1410436882000" /><br /> REF: SE samples, 44100Hz, 16bit; OUT: Lame <span class="hilight">-V9</span>, 22050Hz, 32bit; <em>Tb</em> = 100 ms; <em>Df</em> = <strong>-24.5 dB</strong></td> </tr> <tr> <td> <br /> <strong>Fig.11.</strong> Diffrograms of Lame 3.99.5 at different quality settings with nine SE samples.</td> </tr> </tbody> </table> <p> </p> <p> Obviously, degradation of initial waveform in iPhone 6 (<em>Df</em> = -24.4dB) and in Lame -V9 (<em>Df</em> = -24.5dB) has different consequences for perceived audio quality. So, comparison of <em>Df</em> values should be done with great care.</p> <p> Nevertheless, <em>Df</em> values in the form of diffrogram could give valuable insights into features of a signal processing being investigated. For this purpose short time blocks <em>(Tb = 50ms)</em> are more appropriate. Equally, diffrogram can be computed with extensive and greatly varied audio material and then resulting <em>Df</em> values can be analyzed with statistical methods. In this case 400ms-3sec time blocks are more helpful. Exactly thanks to possibility of using various signals for computing difference level, the parameter and diffrogram have high research potential. To be continued ...</p> <p> </p> <h2 style="text-align: right;"> <a id="part2" name="part2"></a>Part 2</h2> <p style="text-align: right;"> Draft. 2015 Jan 25. Live research.</p> <p> </p> <p> Before we continue some changes should be noted:</p> <ul> <li> standard logarithmic scale of frequencies is used now for spectrogram (see Fig.12) instead of square-law scale used in Part 1</li> <li> <em>Median</em> looks like a better estimator of central tendency for <em>Df</em> values, so it is used now instead of <em>Mean</em></li> <li> instead of <em>Time block</em> the standard term <em>Time window</em> is used for computing a single <em>Df</em> value (<em>Tw = Tb</em>)</li> </ul> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <p> <img alt="Standard logarithmic frequency scale for spectrogram" src="http://soundexpert.org/documents/10179/130750/iPhone5s_GLK_mono_50_newfreqscale.png/e15b987a-e5b5-4131-88cd-133143c25b39?t=1422202082000" style="width: 348px; height: 112px;" /></p> </td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 12.</strong> “New” logarithmic frequency scale for spectrogram. The old one is in Fig.2.<br /> <em>Tw</em> = 50 ms<br /> <em>Df(median)</em> = -29.3 dB</p> </td> </tr> </tbody> </table> <p> </p> <p> Difrorgams below show distortion of some standard test signals (30sec, -10dBFS RMS) which have been transferred through the device under test – iBasso DX50 audio player (mono(L+R), resistive 33 Ohm load).</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with sinusoidal signal 1 kHz" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_sine1k_mono_100-79.5324-79.0802-45.2202.png/9cbb9321-18d9-4999-b7f0-370c58c1512b?t=1422202080000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 13.</strong> Diffrogram of DX50 with sinusoidal signal 1kHz<br /> REF: sine 1kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 30s<br /> <em>Tw</em> = 100ms<br /> <em>Df(min)</em>= -79.5 dB, <em>Df(median)</em>= <strong>-79.1 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with sinusoidal signal 12.5 kHz" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_sine12.5k_mono_100-78.9035-64.8288-46.2091.png/fe531db4-5912-4642-8a0c-2c0eaf42c00d?t=1422202081000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 14.</strong> Diffrogram of DX50 with sinusoidal signal 12.5kHz. Slow change of <em>Df</em> values reflect instability of DX50 internal clock. Testing sine signal of higher frequency better reveals oscillation, which is not noticeable at 1kHz.<br /> REF: sine 12.5kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 30 s<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -78.9 dB, <em>Df(median)</em>= <strong>-64.8 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with sinusoidal signal 12.5kHz as in Fig.14 but with smaller time frame for warp processing (100ms instead of 30s)" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_sine12.5k_mono_100-79.3891-78.7957-48.0822.png/af0da885-18fc-4258-be30-df82c7b5cb79?t=1422202081000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 14.1.</strong> Diffrogram of DX50 with sinusoidal signal 12.5kHz as in Fig.14 but with smaller time frame for warp processing (100ms instead of 30s). Oscillation of sampling frequency is not noticeable in this case; accuracy of reproduction of sine 12.5k is only slightly worse than of sine 1k from Fig.13.<br /> REF: sine 12.5kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -79.4 dB, <em>Df(median)</em>= <strong>-78.8 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with DFD signal: 12.5 kHz mean, 80 Hz difference (12460 Hz + 12540 Hz)" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_DFD12.5k_mono_100-75.2925-75.0212-58.6619.png/1ec2e89d-e0a0-4aca-ae91-6af8e577e4fa?t=1422202078000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 15.</strong> Diffrogram of DX50 with DFD signal: 12.5 kHz mean, 80 Hz difference (12460 Hz + 12540 Hz). For elimination of sampling frequency oscillation warping time frame is also set to 100ms. Lower <em>Df</em> values in comparison with Fig.14.1 reveal presence of inter-modulation distortion (IMD).<br /> REF: DFD 12.5kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -75.3 dB, <em>Df(median)</em>= <strong>-75.0 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with MOD-SMPTE 4-to-1 signal: 60 Hz + 7 kHz, 4:1" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_MOD-SMPTE60-7_mono_100-47.3930-47.3774-30.7655.png/0ea8e044-f000-4e4e-8186-4505d346e528?t=1422202079000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 16.</strong> Diffrogram of DX50 with MOD-SMPTE 4-to-1 signal: 60 Hz + 7 kHz, 4:1. Substantially lower <em>Df</em> values are caused by phase inaccurate reproduction of different frequencies in iBasso DX50. This test signal is highly affected by parameters of time warping and is not suitable for IMD assessment within <em>Df</em> metric.<br /> REF: MOD-SMPTE 4-to-1, 60 Hz + 7 kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -47.4 dB, <em>Df(median)</em>= <strong>-47.4 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with Sweep tone 20Hz-20kHz (linear)" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_sweep20-20k_mono_100-79.5482-78.3992-12.3482.png/4455f0b3-83a2-4ac6-869e-3752c2a964f5?t=1422202082000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 17.</strong> Diffrogram of DX50 with Sweep tone 20Hz-20kHz (linear). <em>Df</em> values increase slightly with frequency (“greener” right end) visually indicating that higher frequencies are reproduced with lower accuracy. This test signal is highly affected by parameters of time warping and should be used with caution.<br /> REF: sweep 20-20kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 200 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -79.5 dB, <em>Df(median)</em>= <strong>-78.4 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with square wave 1 kHz" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_square1k_mono_100-37.3851-37.3758-34.9848.png/c63727f8-9f95-4a4f-8750-fb161f27c020?t=1422202081000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 18.</strong> Diffrogram of DX50 with square wave 1kHz. This wave-form is distorted much higher than the sine wave from Fig.13<br /> REF: square wave 1 kHz, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -37.4 dB, <em>Df(median)</em>= <strong>-37.4 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with white noise" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_wnoise_mono_100-26.5911-25.0076-22.4497.png/405eeb5b-a6b3-40a8-8262-da730743fce1?t=1422202082000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 19.</strong> Diffrogram of DX50 with white noise.<br /> REF: white noise, 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -26.6 dB, <em>Df(median)</em>= <strong>-25.0 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Diffrogram of DX50 with “program simulation noise” (BS EN 50332-1)" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_pnoise_mono_100-22.4173-19.4152-15.7128.png/cf8b632a-35bf-401a-be38-295b21a750c6?t=1422202079000" style="width: 300px; height: 99px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 20.</strong> Diffrogram of DX50 with “program simulation noise” (BS EN 50332-1), whose spectral content is representative of music and speech. A good candidate for being a “standard” test signal within <em>Df</em> metric.<br /> REF: pink noise, filtered and dynamically compressed (BS EN 50332-1), 44100Hz, 16bit<br /> OUT: iBasso DX50, 96000Hz, 24bit<br /> <em>WarpFrame</em> = 100 ms<br /> <em>Tw</em> = 100 ms<br /> <em>Df(min)</em>= -22.4 dB, <em>Df(median)</em>= <strong>-19.4 dB</strong></p> </td> </tr> </tbody> </table> <p> </p> <p> The list of possible test signals is limited only by creativity of researcher. Though not all of them are useful within <em>Df</em> audio metric. Additional research is required.</p> <p> Each diffrogram provides a set of <em>Df</em> values which can be further analyzed with statistical methods. For example Fig.21 shows diffrogram of iBasso DX50 with nine SE samples and Fig.22 shows histogram of these <em>Df</em> values.</p> <p> </p> <p> <img alt="Diffrogram of iBasso DX50 with nine SE samples" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_SE9_left_100-47.7726-23.2014%2B0.3811.png/132474cc-5099-4042-b86b-f0f9cf28d19c?t=1422202080000" style="width: 931px; height: 113px;" /></p> <p> <strong>Figure 21</strong>. Diffrogram of iBasso DX50 with nine SE samples.<br /> REF: SE samples, 44100Hz, 16bit; OUT: iBasso DX50, 96000Hz, 24bit; <em>Tw</em> = 100 ms; <em>Df(min)</em>= -47.8 dB, <em>Df(median)</em>= <strong>-23.2 dB</strong></p> <p> </p> <p> <img alt="Histogram of Df values (N=931) from diffrogram in Fig.21" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_400x931-47.7726-23.2014.png/3f83dfda-fc1b-431d-88f3-b993a3310b57?t=1422202077000" style="width: 986px; height: 150px;" /></p> <p> <strong>Figure 22</strong>. Histogram of <em>Df</em> values (<em>N</em>=931) from diffrogram in Fig.21.<br /> REF: SE samples, 44100Hz, 16bit; OUT: iBasso DX50, 96000Hz, 24bit; <em>Tw</em> = 100 ms; <em>Df(min)</em>= -47.8 dB, <em>Df(median)</em>= <strong>-23.2 dB</strong></p> <p> </p> <p> As SE samples represent different types of audio material and the number of <em>Df</em> values (<em>N</em>=931) is relatively small the distribution of <em>Df</em> looks pretty random. For big <em>N</em> the distribution becomes “more Gaussian”. For example, using the whole Pink Floyd album “The Dark Side Of The Moon” (Discovery Edition, 2011 Remaster, EMI) as a test signal gives 6440 <em>Df</em> values (<em>Tw</em>=400ms). Diffrogram of the third track “On The Run” is shown in Fig.23.</p> <p> </p> <p> <img alt="Diffrogram of iBasso DX50 with “On The Run” track from Pink Floyd" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_On-The-Run_mono_400-25.7106-19.3766-11.6270.png/29bc9798-c85f-4eb8-90bb-221394c88052?t=1422202079000" style="width: 563px; height: 99px;" /></p> <p> <strong>Figure 23</strong>. Diffrogram of iBasso DX50 with “On The Run” track by Pink Floyd.<br /> REF: Pink Floyd, “On The Run”, 3:45, 44100Hz, 16bit; OUT: iBasso DX50, 96000Hz, 24bit; <em>Tw</em> = 400 ms; <em>Df(min)</em>= -25.7 dB, <em>Df(median)</em>= <strong>-19.4 dB</strong></p> <p> </p> <p> Histogram of <em>Df</em> values for iBasso DX50 with the whole album “The Dark Side Of The Moon” (<em>N</em>=6440) is shown in Fig.24. For comparison Fig.25 shows similar histogram for another audio player - iriver E100.</p> <p> </p> <p> <img alt="Histogram of Df values for iBasso DX50 and the whole album “The Dark Side Of The Moon” (N=6440)" src="http://soundexpert.org/documents/10179/130750/iBassoDX50_400x6440-39.1319-20.0631.png/bda4fde6-c194-48a0-85bd-69be93dd522c?t=1422202077000" style="width: 986px; height: 236px;" /></p> <p> <strong>Figure 24</strong>. Histogram of <em>Df</em> values for iBasso DX50 with the whole album “The Dark Side Of The Moon” (<em>N</em>=6440).<br /> REF: Pink Floyd, “The Dark Side Of The Moon”, 43:00, 44100Hz, 16bit; OUT: iBasso DX50, 96000Hz, 24bit; <em>Tw</em> = 400 ms; <em>Df(min)</em>= -39.1 dB, <em>Df(median)</em>= <strong>-20.1 dB</strong></p> <p> <img alt="Histogram of Df values for iriver E100 and the whole album “The Dark Side Of The Moon” (N=6440)" src="http://soundexpert.org/documents/10179/130750/iriverE100_400x6440-34.4826-16.7692.png/edc23848-55fe-4b69-86de-22955c26eb1f?t=1422202083000" style="width: 986px; height: 250px;" /></p> <p> <strong>Figure 25</strong>. Histogram of <em>Df</em> values for iriver E100 with the whole album “The Dark Side Of The Moon” (<em>N</em>=6440).<br /> REF: Pink Floyd, “The Dark Side Of The Moon”, 43:00, 44100Hz, 16bit; OUT: iriver E100, 96000Hz, 24bit; <em>Tw</em> = 400 ms; <em>Df(min)</em>= -34.5 dB, <em>Df(median)</em>= <strong>-16.8 dB</strong></p> <p> </p> <p> Pretty evident that one player preserves initial waveform better than the other. Comparison of such <em>Df</em> sets can be done with standard boxplots showing median and 25\75 percentiles of data, thus giving estimation of location and spread of <em>Df</em> values (Fig.26).</p> <p> </p> <table border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="vertical-align: top; width: 400px;"> <img alt="Boxplot of Df values (N=6440) for two audio players" src="http://soundexpert.org/documents/10179/130750/df_boxplot_dx50-e100.png/3e82433c-ec40-4278-a631-b2c1c6852d91?t=1422202075000" style="width: 353px; height: 313px;" /></td> <td style="vertical-align: top; padding-left: 30px;"> <p> <strong>Figure 26.</strong> Boxplot of <em>Df</em> values (<em>N</em>=6440) for two audio players. Each <em>Df</em> value estimates similarity of a small portion (400ms) of initial digital waveform with corresponding portion at headphone output of player. The less the value in dB, the better.</p> </td> </tr> </tbody> </table> <p> </p> <p> And finally all objective measurements according to this audio metric could be summarized as in Fig.27 showing performance of device under test with various test signals in one simple view.</p> <p> </p> <p> <img alt="Results of testing iBasso DX50 digital audio player" src="http://soundexpert.org/documents/10179/130750/iBassoDX50%40SoundExpert.png/ebed7f1a-74d7-4ec7-8c35-4fb71c3d2af9?t=1435225018000" style="width: 1000px; height: 344px;" /><br /> <strong>Figure 27</strong>. Results of testing iBasso DX50 digital audio player with various audio signals and single measurement approach based on Difference level parameter.</p> <p> </p> <p> </p> <h2 style="text-align: right;"> <a id="part3" name="part3"></a>Diffrogram utility (Matlab)</h2> <h3> Matlab code for computing Difference levels and building diffrograms; with examples of usage.</h3> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v3.34.zip" target="_blank">diffrogram_v3.34.zip</a> (9.8kB) - correct phase computation, no readme (soon), help is in the code</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v3.33.zip/1f41df98-a4d5-4696-b019-041533a62a35">diffrogram_v3.33.zip</a> (9.5kB) - more accurate stereo-to-mono conversion, precise freq. scale, no readme (soon), help is in the code</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v3.32.zip">diffrogram_v3.32.zip</a> (8.8kB) - power output added, no readme (soon), help is in the code</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v3.31.zip/d220bd2c-8334-4db5-afe7-533305883745">diffrogram_v3.31.zip</a> (8.8kB) - bug fix, no readme (soon), help is in the code</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v3.3.zip/5720bb0e-e100-4053-b8ab-29723a014a3c">diffrogram_v3.3.zip</a> (8.7kB) - no readme (soon), help is in the code</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v2.4.zip">diffrogram_v2.4.zip</a> (12.6M) - calibrated accuracy</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v2.3.zip">diffrogram_v2.3.zip</a> (872k) - usability improvements</p> <p> <a href="http://soundexpert.org/documents/10179/309629/diffrogram_v2.2.zip">diffrogram_v2.2.zip</a> (832k) - first public release</p> <p> </p> <p> </p>Serge Smirnoff2014-09-10T09:25:00ZAudio quality of Bluetooth aptX and aptX HDSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/audio-quality-of-bluetooth-aptx2019-08-02T09:51:34Z2014-04-09T10:04:00Z<p> Almost six years have passed since the last <a href="http://soundexpert.org/news/-/blogs/bluetooth-audio-quality-a2dp">SE article about bluetooth (BT) audio</a>. It's time to return to the topic following some developments in the field. Even a few years ago it was clear that BT is capable of delivering high quality audio. <a href="http://soundexpert.org/encoders-320-kbps">SE listening tests</a> showed that mandatory audio codec SBC for BT A2DP profile is not bad at all. In “High Quality” mode (@328kbit/s) it is on a par with ATRAC SP (Type-R, @292kbit/s) compression algorithm which is used in Minidisc recorders/players. In “Middle Quality” mode (@229kbit/s) it is roughly comparable with mp3@128kbit/s or aac@96kbit/s. At max possible bitrate 372kbit/s SBC codec is comparable with aac@192kbit/s and most artifacts it produces are beyond human perception. Close positioning of the two codecs – SBC (High Quality) and ATRAC SP (Type-R) – on perceptual quality scale is revealing. Recordings made on Minidisk equipment with ATRAC SP were considered to be of high fidelity by most demanding listeners. It is an example of combination of barely acceptable audio codec with perfectly designed audio circuits. As opposed to ATRAC equipment, early BT A2DP devices, having on board the commensurable audio codec SBC, performed poorly just because their audio circuitry was of simplistic design. In other words BT audio potential was not fully utilized.</p> <p> At the same time the demand for high quality BT audio was high, because this technology has some clear benefits for consumers:</p> <ul> <li> absence of wires, obviously</li> <li> audio quality of such devices are fully determined by receiving side. For example BT headphones can sound exactly the same with different sources of signal – phones/players, tablets, laptops etc., which are just sources of standard digital stream in this scenario.</li> </ul> So, it was clear that sooner or later somebody will hammer all those BT audio drawbacks and will offer a more matured solution for demanding listeners. Finally UK based semiconductor company CSR, which already had experience in developing and manufacturing of BT chips, did this. In particular the company: <ol> <li> developed new BT chips with carefully designed audio circuits</li> <li> added its propriatery audio codec aptX (acquired with APT Licensing Ltd in 2010) in addition to mandatory SBC codec</li> <li> implemented more strict control over manufacturers who use CSR BT solutions in their products</li> </ol> As it was shown above the problem of poor BT audio could be solved by taking measures (1) and (3) alone. Improvement in codec efficiency is just an accessory plus. The more so as such improvement is hard to achieve due to tough conditions for any BT audio codec: <ul> <li> low complexity of algorithm (to constrain energy consumption)</li> <li> low encoding-decoding delay (for better video and gaming experience)</li> <li> limited bandwidth of A2DP profile (max. 721kbit/s, less in real-life scenarios)</li> </ul> But no matter what was behind the CSR decision to use some other codec in addition to mandatory and pretty acceptable SBC, the choice of aptX looks logical from audio quality perspective. This family of codecs are successfully used in professional audio since 1990s thanks to their low complexity and absence of psychoacoustic masking. This results in low delay and stable/predictive perceptual quality with various audio material. CSR uses in their BT chips aptX codec with the following parameters (specs by CSR): <ul> <li> Compression ratio: 4:1</li> <li> Audio Format: 16-bit, 44.1kHz</li> <li> Data Rates: 352kbps</li> <li> Frequency Response: 10Hz to 22kHz</li> <li> Algorithmic Delay: <1.89ms @ Fs 48KHz</li> <li> Dynamic Range: 16-bit: >92dB</li> <li> THD+N: -68.8dB</li> </ul> <hr /> <p align="right"> August 2018</p> <p> Starting from version 4.0 A/V processor ffmpeg has encoding/decoding capabilities for aptX and aptX HD formats. The same codecs are also available as separate command line utilities <a href="https://github.com/pali/libopenaptx" target="_blank">openaptxenc and openaptxdec</a>.</p> <p> Both codecs were added to SE engine for blind testing:</p> <p> <strong>aptX CBR@352.8 (Bluetooth)</strong> - Codec for Bluetooth A2DP profile, CBR, 352.8 kbit/s FBR<br /> CODER: ffmpeg 4.0.2 (Lavc58.18.100 aptx)<br /> - usage: ffmpeg -i ref.wav -acodec aptx out.aptx<br /> - 44100 Hz, 16bit<br /> DECODER: ffmpeg 4.0.2 (Lavc58.18.100 pcm_s16le)<br /> - usage: ffmpeg -sample_rate 44100 -i out.aptx out.wav</p> <p> <strong>aptX HD CBR@529.2 (Bluetooth)</strong> - Codec for Bluetooth A2DP profile, CBR, 529.2 kbit/s FBR<br /> CODER: ffmpeg 4.0.2 (Lavc58.18.100 aptx_hd)<br /> - usage: ffmpeg -i ref.wav -acodec aptx_hd out.aptxhd<br /> - 44100 Hz, 16bit<br /> DECODER: ffmpeg 4.0.2 (Lavc58.18.100 pcm_s16le)<br /> - usage: ffmpeg -sample_rate 44100 -i out.aptxhd out.wav</p> <p> Their results (inaccurate so far) are available on the page <a href="http://soundexpert.org/encoders-320-kbps" target="_blank">Encoders 320+ kbit/s</a>. For those who would like to participate in SE listening tests there is a short instruction on that page below the ratings.<a id="aptxmeasurements" name="aptxmeasurements"></a></p> <h3> Objective measurements of aptX and aptX HD using music based df-metric</h3> <p> Usually objective measurements of audio encoders are considered as incorrect method for judging their audio quality. This is true and can be explained in simple words as follows. The encoders process different parts of complex audio signal differently according to some rules specific to each particular encoder. So, measurements performed with some technical signals say almost nothing about encoder's behavior with real-life audio material.</p> <p> Part of this problem can be solved by using music/voice as a test signal. For the purpose special algorithm was developed. It compares two waveforms and computes level of difference between them. The algorithm is smart enough not to account basic amplitude, pitch and phase distortions, if any, as they don't affect perceived sound quality. Resulting audio parameter is called Difference Level (<em>Df</em>,dB); it shows how different two "canonical" waveforms are. If they are perfectly identical, <em>Df = -∞</em> dB; if they are completely different, <em>Df = 0</em> dB.</p> <p> <a href="http://soundexpert.org/news/-/blogs/objective-difference-measurements-to-predict-listening-test-results-" target="_blank">Preliminary research</a> showed that in some cases (those, which met definite conditions) such objective measurements, performed using substantial amount of real-life audio material, correlate well to subjective estimations of sound quality. And though the research is still in progress I decided to publish results of such measurements as they look interesting and promising enough. Those who are not interested in scientific details can scroll to the end of the article for conclusions.</p> <p> Measurements of Bluetooth audio codecs were performed using Pink Floyd album "The Dark Side Of The Moon" as a test signal. Output waveforms of the codecs were compared with the reference waveform piece-wise (400ms). Thus, the measurement algorithm computed for each codec a sequence of 6430 <em>Df</em> values. The sequence shows to what extent different parts of the test signal were distorted by each particular codec. Figure 1 shows histograms of those sequences with medians and 25/75 percentiles indicated.</p> <p> aptX and aptX HD encoding/decoding was performed using ffmpeg utility with settings mentioned above in the article. For SBC encoding/decoding the reference SBC codec was used - SBC Encoder LIB Version 1.5 (Philips). This mandatory BT codec was measured in three quality modes:</p> <ul> <li> @201 kbit/s - Low Quality</li> <li> @229 kbit/s - Middle Quality</li> <li> @328 kbit/s - High Quality</li> </ul> and two methods of bits allocation: <ul> <li> Loudness</li> <li> SNR</li> </ul> <p> Command lines used for SBC encoding:</p> <p style="margin-left: 40px;"> <code>sbc_encoder.exe -jv -p -r328000 -oout.sbc ref.wav</code> - SBC@328 with Loudness bits allocation<br /> <code>sbc_encoder.exe -jv -r328000 -oout.sbc ref.wav</code> - SBC@328 with SNR bits allocation (SNR is default for the encoder)</p> <p> For better understanding of this measurement method two other codecs were added to the test:</p> <ul> <li> IMA ADPCM 4:1 @354 kbit/s - close relative to our codecs under test</li> <li> AAC @256 kbit/s (iTunes Plus) - a very different codec</li> </ul> <p> </p> <p> <img alt="Histograms of Df sequences for the codecs under test" src="http://soundexpert.org/documents/10179/1131562/btaptx-histograms.png/776f0177-83ae-4805-8231-169ea3523d17?t=1535020731000" style="width: 1000px; height: 1165px;" /></p> <p style="margin-left: 40px;"> <strong>Figure 1</strong>. Histograms of df-sequences for the codecs under test. Medians are estimators of average waveform degradation. Shape of histograms relates to character/type of waveform degradation.<br /> </p> <p> There is a strong temptation to conclude from the above figure that scores of perceived sound quality for the codecs will follow the medians of their histograms. Unfortunately the relation is not so simple. The medians show only the amount of waveform degradation but they say nothing about character of that degradation. As in standard audio metric - not all distortions are equal from listener's perspective. <em>Df</em> measurements are good indicators of sound quality only in cases where types of waveform degradation are similar. In other words, <strong>if <em>artifact signatures</em> are similar within a group of devices under test, then their measurements of waveform degradation correlate well to perceived sound quality estimations</strong>.</p> <p> So, we need a measure of artifacts' similarity. Some basic idea about similarity of the codecs can be derived from the shapes of their histograms. While SBC and aptX histograms are quite similar, ADPCM and especially AAC ones look different. But for sure we need more defined method for similarity estimation. As for each codec we have a long sequence of <em>Df</em> values, not a single median, and such sequence shows in great detail what parts of the signal were degraded to what extent, this sequence can be safely considered as an artifact signature of the codec. Comparing such signatures we can determine a group of codecs with similar artifacts. In mathematics such tasks are solved using methods of cluster analysis. In order to use it in our case we should find some measure of distance between df-sequences which will serve as a measure of similarity between them. Multiple experiments with various devices under test revealed that <em>Distance Correlation</em> (Gábor J. Székely, 2005) works best as a measure of distance in our case (<em>Spearman's rank correlation</em> is the second). Dendrogram on Figure 2 shows resulting distances between our df-sequences.</p> <p> </p> <table style="width:100%;"> <tbody> <tr> <td> <p> <img alt="Dendrogram showing similarity between codecs" src="http://soundexpert.org/documents/10179/1131562/btaptx-dendrogram.png/907bf96a-2623-43e7-8e98-67727a025a78?t=1535020716000" style="width: 705px; height: 470px; padding-right: 20px;" /></p> </td> <td style="vertical-align: top;"> <strong>Figure 2</strong>. Dendrogram showing similarity of codecs. The shorter the link between two codecs, the more similar their artifact signatures. The distance value 0.3 is critical for relation of <em>Df</em> measurements to subjective scores.</td> </tr> </tbody> </table> <p> </p> <p> Here we can see how distances between codecs gradually increase from SBC to aptX, ADPCM, AAC. Previous experiments with various codecs showed that for distances greater than 0.3 the relation of <em>Df</em> measurements to subjective scores starts to degrade rapidly. This is the point of uncertainty. Below it the relation holds. So, audio quality of SBC and both aptX codecs can be safely judged by their <em>Df</em> measurements (medians); ADPCM codec is slightly above the point of uncertainty and its quality can be assessed in our case with greater error only; nothing can be said about audio quality of AAC, its artifact signature differs greatly from the ones of other codecs in our set.</p> <p> Now, we can return to Figure 1 and make some conclusions.</p> <p> <strong>(1)</strong> aptX codec used in BT applications is no better than SBC@328. Despite slightly lower algorithmic delay of aptX both SBC and aptX codecs provide the same 100-150ms latency in real-life BT applications. If you hear the difference between SBC and aptX in some BT product, there can be only two explanations - placebo effect or using SBC in Middle or Low Quality modes. It's pretty clear now that aptX was necessary to CSR as a key element of its marketing strategy aimed at effective selling of new CSR BT chips/solutions to manufacturers (with license fees) which in turn effectively sell their "innovative" BT products to consumers. <strong>AptX is just a copperless overpriced audio cable</strong>. Audio industry at its best.</p> <p> <strong>(2)</strong> aptX HD is high-bitrate version of aptX. It has clearly noticeable increase in sound quality (not dramatic though taking into account the increase in bitrate)</p> <p> <strong>(3)</strong> Carefully designed headphones (or speakers) with SBC on board and indicator of quality mode will satisfy 99% of listeners and will be compatible with all BT audio sources on the market.</p> <p> </p> <hr /> <h4> Update 2019.06</h4> <p> New article “Audio quality of SBC XQ Bluetooth audio codec” is available - <a href="http://soundexpert.org/articles/-/blogs/audio-quality-of-sbc-xq-bluetooth-audio-codec">http://soundexpert.org/articles/-/blogs/audio-quality-of-sbc-xq-bluetooth-audio-codec</a></p> <p> </p> <h3> Appendix</h3> <p> Below are <em>Df</em> measurements of the codecs with standard technical signals. For research purposes only.</p> <p> <img alt="Diffrograms of the codecs with tech. signals" src="http://soundexpert.org/documents/10179/1131562/sbc-aptx-df-tech.png/9265cb8a-4f7d-43d3-8483-79da36bdb546?t=1535207974000" style="width: 1000px; height: 1375px;" /></p> <p style="margin: 0 0 0 50px;"> <strong>Figure 3</strong>. Diffrograms with corresponding <em>Df</em> median values in dB for the codecs. Order of the codecs is the same as in Fig.1. Numbers in brackets are for quick referencing. Details of the tech. signals can be found <a href="http://soundexpert.org/test-signals">here</a>. More about diffrograms - <a href="http://soundexpert.org/news/-/blogs/visualization-of-distortion">here</a>.</p> <p> </p> <p> None of these signals can be used for assessment of sound quality, they are for better understanding of encoders' internal mechanics only.</p> <p> </p> <hr /> <p> </p> <p style="text-align: center;"> <img alt="" src="http://soundexpert.org/documents/10179/1131562/se-ape.png/d56c7221-c863-45aa-86bc-008f9cdbe862?t=1564739094000" style="width: 900px; height: 450px;" /></p> <p> </p>Serge Smirnoff2014-04-09T10:04:00ZOpus, AAC, Vorbis, MP3, MPC at 128 kbit/sSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/opus-aac-vorbis-mp3-mpc-at-128-kbit-s2014-03-24T21:59:29Z2014-03-24T09:25:00Z<p> This listening test has almost the same codec contenders as the previous <a href="http://soundexpert.org/news/-/blogs/opus-aac-vorbis-mp3-at-96-kbit-s">@96 one</a> with the following differences:</p> <ul> <li> All encoders have integer/discrete quality settings which are normally used in practice; in other words, quality parameters were not adjusted to get equal resulting bitrates with nine SE test samples; so the test will show how these codecs with usual settings compare with each other; for codecs with close resulting bitrates some conclusions about their efficiency can be derived as well</li> <li> Opus version was updated from 1.0.2 to 1.1 with some quality fixes</li> <li> CoreAudioToolbox 7.9.8.2 for QuikTime encoder was updated to 7.9.8.3 without any quality improvements</li> <li> AAC encoder by Fraunhofer from Winamp was updated from 1.04 to 1.08</li> <li> New AAC encoder by Fraunhofer from Android Open Source Project was added</li> <li> Musepack MPC was added</li> </ul> <p> </p> <p> Resulting list of contenders:</p> <p> <br /> <strong>AAC VBR@112.0 (Winamp 5.666)</strong> - VBR, AAC LC</p> <ul> <li> AAC Encoder v1.08 (Fraunhofer IIS) from Winamp 5.666: Variable Bitrate, Preset 4</li> <li> The encoder is also available as CLI utility and can be downloaded from <a href="https://github.com/tmkk/fhgaacenc" target="_blank">https://github.com/tmkk/fhgaacenc</a></li> </ul> <p> <strong>AAC VBR@118.4 (iTunes 11.1.3)</strong> - TrueVBR, AAC LC</p> <ul> <li> iTunes 11.1.3.8 or QuickTime 7.7.4 AAC Encoder via qaac 2.30 (CoreAudioToolbox 7.9.8.3): qaac -V63 ref.wav</li> <li> The encoder is included in such Apple products as iTunes, QuickTime, Safari; though not all of its features can be reached through these applications. For greater flexibility the CLI utility <em>qaac</em> can be used</li> <li> download from <a href="https://sites.google.com/site/qaacpage/" target="_blank">https://sites.google.com/site/qaacpage/</a></li> </ul> <p> <strong>AAC VBR@117.5 (NeroRef 1540)</strong> - CVBR, AAC LC</p> <ul> <li> Nero AAC Encoder 1.5.4.0 (build 2010-02-18): neroAacEnc.exe -q 0.4 -if ref.wav -of out.mp4</li> <li> download from <a href="http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php" target="_blank">http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php</a></li> </ul> <p> <strong>Vorbis VBR@119.4 (Xiph 1.3.3)</strong></p> <ul> <li> OggEnc v2.87 (libVorbis 1.3.3): oggenc2 -q4 ref.wav</li> <li> download from <a href="http://vorbis.com/" target="_blank">http://vorbis.com/</a></li> </ul> <p> <strong>Opus VBR@115.7 (libopus 1.1)</strong></p> <ul> <li> encode: opusenc --bitrate 96 ref48.wav (44.1/16 -> 48/24 by Audition CS6)</li> <li> The encoder operates at 48kHz only, so for other sample rates (as in our case) resampling is required. Some good quality resampler is already integrated into the codec but we used the external one from Audition CS6; the complete test files production chain: reference test files 44.1/16 -->> 48/24(Audition CS6) -->> opusenc -->> decode by foobar2000(48/32) -->> 44.1/32(Audition CS6) -->> test files production</li> <li> download from <a href="http://opus-codec.org/downloads/" target="_blank">http://opus-codec.org/downloads/</a></li> </ul> <p> <strong>mp3 VBR@113.7 (Lame 3.99.5)</strong> - MPEG-1 Layer 3, VBR</p> <ul> <li> encode: lame -V5 ref.wav</li> <li> download from <a href="http://www.rarewares.org/mp3-lame-bundle.php" target="_blank">http://www.rarewares.org/mp3-lame-bundle.php</a></li> </ul> <strong>AAC VBR@110.9 (libfdk 3.4.12)</strong> - MPEG-4 AAC LC, VBR <ul> <li> AAC encoder library by Fraunhofer from Android Open Source Project; its license doesn't allow distribution of binaries, the source code is here - <a href="http://sourceforge.net/projects/opencore-amr/files/fdk-aac/" target="_blank">http://sourceforge.net/projects/opencore-amr/files/fdk-aac/</a></li> <li> encoding via CLI utility <em>fdkaac</em> (<a href="https://github.com/nu774/fdkaac" target="_blank">https://github.com/nu774/fdkaac</a>, source code only): fdkaac -m 4 ref.wav</li> <li> the library can also be used with <em>FFmpeg</em> utility - <a href="http://trac.ffmpeg.org/wiki/AACEncodingGuide" target="_blank">http://trac.ffmpeg.org/wiki/AACEncodingGuide</a></li> </ul> <strong>mpc VBR@123.3 (SV8)</strong> - Musepack <ul> <li> encode: mpcenc --quality 4.0 ref.wav out.mpc</li> <li> download from - <a href="http://musepack.net/" target="_blank">http://musepack.net/</a></li> </ul> <p> </p> <p> In addition to usual live ratings on <a href="http://soundexpert.org/encoders-128-kbps">128kbit/s page</a> there will be detailed results of this test when corresponding ratings reach 1% accuracy (example of the detailed report is in the previous <a href="http://soundexpert.org/news/-/blogs/opus-aac-vorbis-mp3-at-96-kbit-s#results">96 kbit/s listening test</a>).</p> <p style="text-align: center;"> <span style="font-size:18px;">***</span></p> <p class="se-message"> SoundExpert reminds you that final conclusion about audio quality of any device added can be made only after finishing corresponding listening test. So we encourage you to take part in testing. SE ratings exist only thanks to visitors like you. Testing is short and easy, visit our <a href="http://soundexpert.org/testing-room">Testing Room</a> for simple 1-2-3 instruction.<br /> <br /> Please, remember, downloading test files from SoundExpert you will not necessarily get the ones of the newly added codecs. SoundExpert testing is blind testing – you don't know the device you test. This is the only reliable way of getting true audio quality ratings, free from any cheating and various human senses other than perception of sound quality. After you have sent your grade you will see the device you tested.</p> <p> Best regards,<br /> SE Team.</p>Serge Smirnoff2014-03-24T09:25:00ZOpus, AAC, Vorbis, MP3 at 96 kbit/sSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/opus-aac-vorbis-mp3-at-96-kbit-s2014-03-30T16:10:08Z2013-04-27T22:18:00Z<p> This listening test follows the similar <a href="http://soundexpert.org/news/-/blogs/opus-aac-and-vorbis-in-64-kbit-s-section">@64 one</a>, finished not so far ago. Codec contenders are the same with a few exceptions:</p> <ul> <li> Opus version was updated from 1.0.1 to 1.0.2</li> <li> Lame mp3 encoder added (3.99.5)</li> <li> QuikTime encoder was updated but without any quality improvements; in this test it is used in True VBR mode.</li> </ul> <p> Final list of contenders:</p> <p> <strong>AAC VBR@89.8 (Winamp 5.63)</strong> - VBR, AAC LC</p> <ul> <li> AAC Encoder v1.04 (Fraunhofer IIS) from Winamp 5.63: Variable Bitrate, Preset 3</li> <li> The encoder is also available as CLI utility and can be downloaded from <a href="https://github.com/tmkk/fhgaacenc" target="_blank">https://github.com/tmkk/fhgaacenc</a></li> </ul> <p> <strong>AAC VBR@92.1 (QTime 7.7.3)</strong> - TrueVBR, AAC LC</p> <ul> <li> QuickTime (7.7.3) AAC Encoder via qaac 2.18 (CoreAudioToolbox 7.9.8.2): qaac -V45 ref.wav</li> <li> The encoder is included in such Apple products as iTunes, QuickTime, Safari; though not all of its features can be reached through these applications. For greater flexibility the CLI utility qaac can be used</li> <li> download from <a href="https://sites.google.com/site/qaacpage/" target="_blank">https://sites.google.com/site/qaacpage/</a></li> </ul> <p> <strong>AAC VBR@90.0 (NeroRef 1540)</strong> - CVBR, AAC LC</p> <ul> <li> Nero AAC Encoder 1.5.4.0 (build 2010-02-18): neroAacEnc.exe -q 0.34 -if ref.wav -of out.mp4</li> <li> download from <a href="http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php" target="_blank">http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php</a></li> </ul> <p> <strong>Vorbis VBR@90.4 (Xiph 1.3.3) </strong><br /> OggEnc v2.87 (libVorbis 1.3.3): oggenc2 -q2.2 ref.wav</p> <ul> <li> download from <a href="http://vorbis.com/" target="_blank">http://vorbis.com/</a></li> </ul> <p> <strong>Opus VBR@90.7 (libopus 1.0.2) </strong></p> <ul> <li> opusenc --bitrate 90 ref48.wav (44.1/16 -> 48/24 by Audition CS6)</li> <li> The encoder operates at 48kHz only, so for other sample rates (as in our case) resampling is required. Some good quality resampler is already integrated into the codec but we used the external one from Audition CS6; the complete test files production chain: reference test files 44.1/16 -->> 48/24(Audition CS6) -->> opusenc -->> decode by foobar2000(48/24) -->> 44.1/32(Audition CS6) -->> test files production</li> <li> download from <a href="http://opus-codec.org/downloads/" target="_blank">http://opus-codec.org/downloads/</a></li> </ul> <p> <strong>mp3 VBR@90.2 (Lame 3.99.5)</strong> - MPEG-1 Layer 3, VBR</p> <ul> <li> encode: lame -V6.9 ref.wav</li> <li> For this quality parameter (-V6.9) Lame down-samples the input from 44.1 kHz to 32 kHz. Decoder's output was up-sampled back to 44.1 with Audition CS6; the complete test files production chain: reference test files 44.1/16 -->> Lame -->> decode by MAD(32/24) -->> 44.1/32(Audition CS6) -->> test files production</li> <li> download from <a href="http://www.rarewares.org/mp3-lame-bundle.php" target="_blank">http://www.rarewares.org/mp3-lame-bundle.php</a></li> </ul> <p> In addition to usual live ratings on <a href="http://soundexpert.org/encoders-96-kbps">96kbit/s page</a> there will be detailed results of this test when corresponding ratings reach 1% accuracy (<a href="http://soundexpert.org/news/-/blogs/opus-aac-and-vorbis-in-64-kbit-s-section#results">example of the detailed report</a> is in the previous 64 kbit/s listening test).</p> <p style="text-align: center;"> <span style="font-size:18px;">***</span></p> <p class="se-message"> SoundExpert reminds you that final conclusion about audio quality of any device added can be made only after finishing corresponding listening test. So we encourage you to take part in testing. SE ratings exist only thanks to visitors like you. Testing is short and easy, visit our <a href="http://soundexpert.org/testing-room">Testing Room</a> for simple 1-2-3 instruction.<br /> <br /> Please, remember, downloading test files from SoundExpert you will not necessarily get the ones of the newly added codecs. SoundExpert testing is blind testing – you don't know the device you test. This is the only reliable way of getting true audio quality ratings, free from any cheating and various human senses other than perception of sound quality. After you have sent your grade you will see the device you tested.</p> <p> Best regards,<br /> SE Team.</p> <br /> <h3> <a id="results" name="results"></a>Results of the test</h3> <p> In addition to usual results on 96kbit/s page here is a detailed analysis of submitted grades for these codecs.</p> <p> <img alt="SoundExpert listening test of Opus, AAC, Vorbis, MP 3 @96 kbit/s (11.2013)" src="http://soundexpert.org/documents/10179/39286/se-test%4096_2013-11.png/27bfb697-25c6-48d9-9f3d-65e63df6cc72?t=1396091573000" style="width: 1000px; height: 547px;" /></p> <br /> <p> All grades submitted for the codecs are below. Numbers in brackets indicate that those grades were discarded by <a href="http://soundexpert.org/news/-/blogs/post-screening-of-grades-in-se-listening-tests">SE automated post-screening mechanism (Median +/- 1.5) </a>and were not used for further calculations. Reference sound samples (BAH, BAS, CST, ...) can be found <a href="http://soundexpert.org/sound-samples">here</a>.</p> <p> </p> <p> <code> AAC VBR@89.8 (Winamp 5.63)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [1] [1] <br /> *7* | [2] <br /> *6* | [2] [4] [2] [1] [3] [2] [1]<br /> ----+-------------------------------------------------------<br /> *5* | 11 6 8 4 9 4 3 5 4<br /> *4* | 3 6 9 9 4 8 9 8 6<br /> *3* | 1 [1] 1 2 2 <br /> *2* | <br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 14 13 17 13 13 13 14 15 10<br /> Mean| 4.79 4.38 4.47 4.31 4.69 4.23 4.07 4.20 4.40<br /> <br /> <br /> <br /> AAC VBR@90.0 (NeroRef 1540)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | <br /> *7* | [1] [1] <br /> *6* | [1] [3] [1] [2] [1] [2] [2] [1]<br /> ----+-------------------------------------------------------<br /> *5* | 8 3 15 5 10 [1] 6 4 3<br /> *4* | 6 9 3 9 3 2 10 8 6<br /> *3* | [1] [1] 11 3<br /> *2* | [1] <br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 14 12 18 14 13 13 16 12 12<br /> Mean| 4.57 4.25 4.83 4.36 4.77 3.15 4.38 4.33 4.00<br /> <br /> <br /> <br /> AAC VBR@92.1 (QTime 7.7.3)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | <br /> *7* | [1] [2] <br /> *6* | [2] [5] [1] [2] [1] [5]<br /> ----+-------------------------------------------------------<br /> *5* | 13 4 1 [1] 1 2 6 10<br /> *4* | 8 9 7 11 6 8 11 8 8<br /> *3* | [1] 1 5 4 12 3 3 1 [1]<br /> *2* | [1] 1 <br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 21 14 12 16 19 12 16 15 18<br /> Mean| 4.62 4.21 3.58 3.81 3.26 3.83 3.94 4.33 4.56<br /> <br /> <br /> <br /> Vorbis VBR@90.4 (Xiph 1.3.3)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [2] <br /> *7* | [1] [1] <br /> *6* | [3] [2] [1] [2] [1] [1]<br /> ----+-------------------------------------------------------<br /> *5* | 4 [2] 2 [1] 1 4 1 11<br /> *4* | 7 4 9 4 9 3 11 7 3<br /> *3* | 1 10 3 10 9 11 1 7 [2]<br /> *2* | 4 <br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 12 14 14 14 19 18 16 15 14<br /> Mean| 4.25 3.29 3.93 3.29 3.58 2.94 4.19 3.60 4.79<br /> <br /> <br /> <br /> mp3 VBR@90.2 (Lame 3.99.5)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [1] [1] [1] <br /> *7* | [1] [1] [1] <br /> *6* | [3] [1] [1] [1] [1] [3] [2] [1]<br /> ----+-------------------------------------------------------<br /> *5* | 9 2 [1] 1 3 4 6<br /> *4* | 5 9 8 7 2 5 14 6<br /> *3* | 2 13 6 13 4 7 3 4<br /> *2* | 11 <br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 14 13 21 14 15 15 15 21 16<br /> Mean| 4.64 4.00 3.38 3.64 3.13 2.27 3.73 4.05 4.13<br /> <br /> <br /> <br /> Opus VBR@90.7 (libopus 1.0.2)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | <br /> *7* | [1]<br /> *6* | [4] [1] [1] [1]<br /> ----+-------------------------------------------------------<br /> *5* | 4 3 2 7 3 2 2<br /> *4* | 7 8 14 7 [1] 6 8 13<br /> *3* | 5 1 2 2 1 8 4 6<br /> *2* | [1] 8 11 1 [1] <br /> *1* | 1 [1]<br /> ----+-------------------------------------------------------<br /> NN | 16 12 18 14 11 12 18 14 21<br /> Mean| 3.94 4.17 4.00 4.50 2.09 2.08 3.61 3.86 3.81 </code></p> <p> </p> <hr /> <h3> Previous graph of the same results (for archival purposes)</h3> <h4> Version 2.0 (11.2013)</h4> <ul> <li> bootstrapped confidence intervals of resulting means (black ones) are computed using nine sample means and shows therefore consistency of codec performance with different types of audio material. In case of small number of test samples (9) confidence intervals of resulting means computed this way have little to no meaning (statisticaly incorrect). In final version of the graph standard/usual method was used (using all grades collected for a codec).</li> </ul> <p> <img alt="SoundExpert listening test of Opus, AAC, Vorbis, MP3 @96 kbit/s (11.2013)" src="http://soundexpert.org/documents/10179/39286/se_ListenTest%4096_11-2013.png/423545a4-535d-4bd5-a8be-59658093429c?t=1384941466000" style="width: 1000px; height: 601px;" /></p> <p style="text-align: center;"> <img alt="" src="http://soundexpert.org/documents/10179/11003/pdf_16x16.png/25c5a047-44b3-4bdf-b84f-9b7240991750?t=1376562871000" style="width: 16px; height: 16px;" /> <strong>Full Res. PDF(16KB)</strong>: <a href="http://soundexpert.org/documents/10179/39286/se_ListenTest%4096_11-2013.pdf/6207b241-ea7d-4917-b9bf-7a4d10a2e1e4" target="_blank">SoundExpert listening test of Opus, AAC, Vorbis, MP3 @96 kbit/s (11.2013)</a></p> <p> </p> <p> </p>Serge Smirnoff2013-04-27T22:18:00ZOpus, AAC and Vorbis in 64 Kbit/s sectionSerge Smirnoffhttp://soundexpert.org/articles/-/blogs/opus-aac-and-vorbis-in-64-kbit-s-section2014-03-30T16:12:06Z2012-11-01T22:51:00Z<p> <img alt="Opus audio codec logo" src="http://soundexpert.org/documents/10179/12683/opus-logo.png/cde8465c-4fb3-4204-91a7-63933a4f1120?t=1376776147947" style="float: right; width: 112px; height: 64px; margin-left: 30px;" /></p> <p> In September 2012 new, open and royalty-free audio codec Opus was standardized by the IETF. First stable release is available on Opus site - <a href="http://www.opus-codec.org/">www.opus-codec.org</a>. SE starts testing of the codec from 64kbit/s section. Other contenders are AAC (three versions from different developers) and Vorbis (Xiph version). Settings for all codecs were adjusted to get the target bitrate as close as possible to each other. As usually the target bitrate (FBR) is calculated on the basis of nine SE sound samples concatenated. Details of the codecs added:</p> <p> <strong>AAC+ VBR@59.2 (Winamp 5.63)</strong> - CVBR, HE-AAC</p> <ul> <li> AAC Encoder v1.04 (Fraunhofer IIS) from Winamp 5.63: Variable Bitrate, Preset 2</li> <li> The encoder is also available as CLI utility and can be downloaded from <a href="https://github.com/tmkk/fhgaacenc">https://github.com/tmkk/fhgaacenc</a></li> </ul> <p> <strong>AAC+ VBR@59.6 (QTime 7.7.2)</strong> - CVBR, HE-AAC</p> <ul> <li> QuickTime (7.7.2) AAC Encoder via qaac 1.45 (CoreAudioToolbox 7.9.8.1): qaac --he -v56 ref.wav</li> <li> The encoder is included in such Apple products as iTunes, QuickTime, Safari; though not all of its features can be reached through these applications. For greater flexibility the CLI utility qaac can be used</li> <li> download from <a href="https://sites.google.com/site/qaacpage/">https://sites.google.com/site/qaacpage/</a></li> </ul> <p> <strong>AAC+ VBR@60.1 (NeroRef 1540)</strong> - CVBR, HE-AAC</p> <ul> <li> Nero AAC Encoder 1.5.4.0 (build 2010-02-18): neroAacEnc.exe -q 0.25 -if ref.wav -of out.mp4</li> <li> download from <a href="http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php">http://www.nero.com/eng/downloads-nerodigital-nero-aac-codec.php</a></li> </ul> <p> <strong>Vorbis VBR@60.3 (Xiph 1.3.3)</strong></p> <ul> <li> OggEnc v2.87 (libVorbis 1.3.3): oggenc2 -q0.3 ref.wav</li> <li> download from <a href="http://vorbis.com/">http://vorbis.com/</a></li> </ul> <p> <strong>Opus VBR@59.9 (libopus 1.0.1)</strong></p> <ul> <li> opusenc --bitrate 59 ref48.wav (44.1/16 -> 48/24 by Audition CS6)</li> <li> The encoder operates at 48kHz only, so for other sample rates (as in our case) resampling is required. Some good quality resampler is already integrated into the codec but we used the external one from Audition CS6; the complete test files production chain: reference test files 44.1/16 -->> 48/24(Audition CS6) -->> opusenc -->> decode by foobar2000(48/24) -->> 44.1/32(Audition CS6) -->> test files production</li> <li> download from <a href="http://opus-codec.org/downloads/">http://opus-codec.org/downloads/</a></li> </ul> <p> All of the codecs are in the system already. Shortly after first grades have been received an incorrect calculation of ratings' reliability in 64kbit/s section was spotted. In order to recalculate all reliability values, all codecs in the section including newly added ones were put on rotation. Also testing of all other devices at SE was paused. After achieving reliable ratings in 64kbit/s section normal operation of SE testing engine will be resumed (such technical details of SE operation are announced in <a href="https://twitter.com/SoundExpertOrg" target="_blank">SE twitter</a> now).</p> <p style="text-align: center;"> ***</p> <p> SE thanks participants of <a href="http://rutracker.org/forum/viewtopic.php?t=4190236" target="_blank">discussion on rutracker.org forum (in Russian)</a> and specially G-Man90 and MindWin for their help on choosing these particular codecs and settings. G-man90's personal web site <a href="http://audiophilesoft.ru/" target="_blank">audiophilesoft.ru (in Russian)</a> also helped a lot with the latest info about audio codecs and other PC audio issues.</p> <p class="se-message"> As usually SoundExpert reminds you that final conclusion about audio quality of any device added can be made only after completing of SE listening tests. So we encourage you to take part. SE ratings exist only thanks to visitors like you. Testing is short and easy, visit our <a href="http://soundexpert.org/testing-room">Testing Room</a> for simple 1-2-3 instruction.<br /> <br /> Please, remember, downloading test files from SoundExpert you will not necessarily get the ones of the newly added codecs. SoundExpert testing is blind testing – you don't know the device you test. This is the only reliable way of getting true audio quality ratings, free from any cheating and various human senses other than perception of sound quality. After you have sent your grade you will see the device you tested.</p> <p> Best regards,<br /> SE Team.</p> <p> <a name="results"></a></p> <h3> Results of the test</h3> <p> Although the ratings of the above codecs had been available just from the beginning of the listening test with gradually increasing reliability (1% accuracy now), more detailed results could be helpful and interesting as well. Below is the outcome of this test in more traditional form with means and confidence intervals.</p> <p> <img alt="Results of SE listening test of Opus, AAC and Vorbis @64 kbit/s (11.2012)" src="http://soundexpert.org/documents/10179/12683/se-test%4064_2012-11.png/36d4c0c7-eea9-4090-93a2-54170cd44ee8?t=1396086134000" style="width: 1000px; height: 547px;" /></p> <p> </p> <p> Numbers of collected grades for each codec and sample are in the tables below. Numbers in brackets indicate that those grades were discarded by <a href="http://soundexpert.org/news/-/blogs/post-screening-of-grades-in-se-listening-tests">SE automated post-screening mechanism (Median +/- 1.5) </a>and were not used for further calculations. Sound samples (BAH, BAS, CST, ...) can be found <a href="http://soundexpert.org/sound-samples">here</a>.</p> <p> </p> <p> <code> AAC+ VBR@59.2 (Winamp 5.63)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [1] <br /> *7* | [1] [1]<br /> *6* | [2] [1] [2] [2] [2] <br /> ----+-------------------------------------------------------<br /> *5* | 10 3 3 7 6 1 2<br /> *4* | 6 12 8 12 8 9 7 3 5<br /> *3* | 2 4 5 9 3<br /> *2* | [1]<br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 16 17 11 16 15 15 13 12 10<br /> Mean| 4.63 4.06 4.27 3.75 4.47 4.40 3.69 3.25 3.90<br /> <br /> <br /> AAC+ VBR@60.1 (NeroRef 1540)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [1] <br /> *7* | <br /> *6* | [2] [1] [1] [1] [2] [2]<br /> ----+-------------------------------------------------------<br /> *5* | 7 11 6 1 [1] [1] 3<br /> *4* | 10 6 7 11 5 7 4 5<br /> *3* | 1 [2] 1 7 9 14 8 11 7<br /> *2* | [1] 1 1<br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 18 17 14 19 10 19 15 15 16<br /> Mean| 4.33 4.65 4.36 3.68 2.90 3.26 3.47 3.27 3.63<br /> <br /> <br /> AAC+ VBR@59.6 (QTime 7.7.2)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | <br /> *7* | [1] <br /> *6* | [1] [1] [1] [1] <br /> ----+-------------------------------------------------------<br /> *5* | 4 5 [1] 3 3 [2] [2]<br /> *4* | 14 10 2 15 5 8 [1] 4<br /> *3* | 2 1 11 12 2 3 1 3 14<br /> *2* | 1 13 1<br /> *1* | <br /> ----+-------------------------------------------------------<br /> NN | 20 16 13 13 17 11 12 16 19<br /> Mean| 4.10 4.25 3.15 2.92 3.88 4.00 4.17 2.19 3.16<br /> <br /> <br /> Opus VBR@59.9 (libopus 1.0.1)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | <br /> *8* | [1] [1] [1]<br /> *7* | [2] <br /> *6* | [3] [1] [2] [3] [2] [2]<br /> ----+-------------------------------------------------------<br /> *5* | [2] [5] [4] 2 [3] [3]<br /> *4* | 1 1 1 11 [1] 1 1 2<br /> *3* | 13 10 13 1 4 9 14 4<br /> *2* | 3 1 9 11 7 1 6<br /> *1* | 4 7 <br /> ----+-------------------------------------------------------<br /> NN | 17 12 14 14 17 18 17 16 12<br /> Mean| 2.88 3.00 3.07 4.07 2.00 1.61 2.65 3.00 2.67<br /> <br /> <br /> Vorbis VBR@60.3 (Xiph 1.3.3)<br /> | BAH BAS CST FMS GLK HRP LOB MOF QRT<br /> ----+-------------------------------------------------------<br /> *9* | [1] <br /> *8* | [1] <br /> *7* | [1] [1] [1] <br /> *6* | [3] [1] [1] <br /> ----+-------------------------------------------------------<br /> *5* | [2] [1] [3] [1] [1] [3] [1]<br /> *4* | 1 [2] 2 1 4 [1] [2] 1<br /> *3* | 5 7 10 14 8 6 6 10<br /> *2* | 8 11 9 3 10 13 8 16 7<br /> *1* | 2 1 [1]<br /> ----+-------------------------------------------------------<br /> NN | 14 18 21 18 22 21 14 17 18<br /> Mean| 2.50 2.39 2.67 2.89 2.73 2.19 2.43 1.94 2.67 </code></p> <p> </p> <p> </p> <hr /> <h3> Previous graphs of the same results (for archival purposes)</h3> <p> </p> <h4> Version 1.0 (04.2013)</h4> <p> Initial graph:</p> <ul> <li> overall confidence intervals of means are computed for all grades of all sound samples (usual/standard approach in listening tests)</li> <li> 95% bootstrap confidence intervals of means are computed using bias corrected and accelerated percentile method</li> <li> small deviation of overall means from corresponding ratings on 64kbit/s page is due to incorrect calculation of overall means on the graph - they are bootstrapped means, not actual means</li> </ul> <p> </p> <p style="text-align: center;"> <img alt="Results of SE listening test of Opus, AAC and Vorbis @64 kbit/s (11.2012)" src="http://soundexpert.org/documents/10179/12683/opus-aac-vorbis_64kbps_11-2012.png/5a87b463-d12d-4212-a617-f00dd44959f7?t=1376776147013" style="width: 725px; height: 486px;" /></p> <p style="text-align: center;"> <img alt="" src="http://soundexpert.org/documents/10179/11003/pdf_16x16.png/25c5a047-44b3-4bdf-b84f-9b7240991750?t=1376562871000" style="width: 16px; height: 16px;" /> <strong>Full Res. PDF(23KB)</strong>: <a href="http://soundexpert.org/documents/10179/12683/opus-aac-vorbis_64kbps_11-2012.pdf/578ab762-937d-42a3-a133-2dac2e4d6f46" target="_blank">Results of SE listening test of Opus, AAC and Vorbis @64 kbit/s (11.2012)</a></p> <p> </p> <h4> Version 2.0 (11.2013)</h4> <p> Slightly different graphical presentation of the same results. Changes:</p> <ul> <li> resulting mean of each codec (black ones) is an average of its nine sample means (previously it was a bootstrapped average of all grades submitted for the codec). Its 95% bootstrapped confidence intervals are also computed using these nine sample means and show therefore consistency of codec performance with different types of audio material. In case of small number of test samples (9) confidence intervals of resulting means computed this way have little to no meaning (statisticaly incorrect). In final version of the graph standard/usual method was used (as in v.1.0).</li> <li> all bootstrapped confidence intervals of means are computed using basic percentile method which is more simple and clear (previously bias corrected and accelerated percentile method was used)</li> <li> sample means are colored for convenience</li> </ul> <p> <img alt="SoundExpert listening test of Opus, AAC, Vorbis @64 kbit/s (11.2012)" src="http://soundexpert.org/documents/10179/12683/se_ListenTest%4064_11-2012.png/97b194d6-e43c-4a3e-acfc-af3ce698aa47?t=1384946365000" style="width: 1000px; height: 547px;" /></p> <p style="text-align: center;"> <img alt="" src="http://soundexpert.org/documents/10179/11003/pdf_16x16.png/25c5a047-44b3-4bdf-b84f-9b7240991750?t=1376562871000" style="width: 16px; height: 16px;" /> <strong>Full Res. PDF(14KB)</strong>: <a href="http://soundexpert.org/documents/10179/12683/se_ListenTest%4064_11-2012.pdf/35f54a2a-f13d-4d02-8777-631fd8fc0fa4" target="_blank">Results of SE listening test of Opus, AAC and Vorbis @64 kbit/s (11.2012)</a></p> <p> </p> <p> </p>Serge Smirnoff2012-11-01T22:51:00Z