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When the CD was designed, 44kHz at 16bits was chosen because that exceeds the limitations of human hearing. With the introduction of Blue-Ray audio, there have

When the CD was designed, 44kHz at 16bits was chosen because that exceeds the limitations of human hearing. With the introduction of Blue-Ray audio, there have been claims that the added resolution makes it sound better. However, some members of the Boston Audio Society did extensive testing where they compared (A/X/B) high-quality Blue-Ray music versus the same music downsampled on the fly to 44kHz/16bit -- and even after extensive listening on very expensive equipment by expert listeners, it was impossible to tell the difference. The results are reported in: E. Brad Meyer and David R. Moran, "Audibility of a CD-Standard A/DA/A Loop Inserted into High-Resolution Audio Playback", JAES Volume 55 Issue 9 pp. 775-779; September 2007. (http://www.aes.org/e-lib/browse.cfm?elib=14195 http://www.aes.org/e-lib/browse.cfm?elib=14195 -- I read a PDF last summer, but now I can't find a non-paywalled version). At the same time, there is widespread agreement that music released on Blu-Ray Audio sounds better than CDs -- but this is not because of the extra bitrate, it's because the sounds engineers pay more attention to details, and the discs are marketed to Hi-Fi enthusiasts, so there is no pressure to e.g. destroy the dynamic range by over-compressing the sound (which makes it sound superficially better on low-end equipment).

rdale 16y ago
"When the CD was designed, 44kHz at 16bits was chosen because that exceeds the limitations of human hearing." No it wasn't, it was designed to be implementable given the technology of the time. Philips thought they were working on a 14 bit system, until Sony changed the spec to be 16 bits. That wasn't because Sony changed their minds about 'the limits of human hearing', it was because they thought they could implement the technology. 30 years later we can implement a bit depth of 24 bits with no problems. According to the Wikipedia article on the history of the Compact Disc (http://en.wikipedia.org/wiki/Compact_Disc http://en.wikipedia.org/wiki/Compact_Disc) the sampling rate was defined for the following reason: "the exact sampling rate of 44.1 kHz was inherited from a method of converting digital audio into an analog video signal for storage on U-matic video tape, which was the most affordable way to transfer data from the recording studio to the CD manufacturer at the time the CD specification was being developed." So again this has absolutely nothing to do with 'the limits of human hearing'. Recording engineers, such as Barry Diament of Soundkeeper Recordings, think that the sound of 24/192 digital matches the output of the live microphone input of their recording desk. Barry Diament doesn't think 16/44.1 is nearly as good. If you buy a recording at a high resolution you can always encode it as an MP3 or ACC so that it fits on your portable player. On the other hand if you buy an MP3 or AAC recording you can't bring back the lost resolution. So if I can fit my entire CD collection onto a cheap 1 TB hard drive, why do we care about how much disk space high resolution 24/96 or 24/192 audio will take up? When you don't have physical media it is trivial for a site to offer a range of resolutions according to the needs of the buyer. If I want 24/96 and someone else is only interested in 128 kps MP3s, then we can both download from the same site and only pay for the quality we need.
- ugh 16y ago
  If people can’t hear the difference in blind tests all that talk about the supposedly better sound is utterly irrelevant.
  - rdale 16y ago
    Why would you value a 'blind test' over what an expert recording engineer, such as Barry Diament, thinks? There are a lot of problems with blind tests, and there has certainly been much discussion about the arguments and counter arguments. If you wheel in a bunch of untrained listeners off the street and get them to listen to recordings they are not familiar with, using a Hi-Fi that they are not familiar with, in stressful un-relaxed circumstances. Why would you expect to get some kind of definitive answer about 16/44.1 vs 24/192 for instance, that somehow trumps the opinion of highly regarded recording engineers?
    - ugh 16y ago
      Evidence trumps authority. I thought that was a basic lesson of science education?
      - rdale 16y ago
        I thought I listed some of the possible flaws in blind tests - there is nothing unscientific about that. If you value the results of any sort of blind test, no matter how badly conducted, over the opinions of recording engineers, then it doesn't seem to be a purely scientific matter to me.
        ugh 16y ago
        Your methodological criticisms are sound, it‘s just that they don’t seem to apply to the quoted paper (I found the PDF): http://www.mesoscale.nl/aes_article.pdf http://www.mesoscale.nl/aes_article.pdf
        16y ago

rdale 16y ago

"When the CD was designed, 44kHz at 16bits was chosen because that exceeds the limitations of human hearing." No it wasn't, it was designed to be implementable given the technology of the time. Philips thought they were working on a 14 bit system, until Sony changed the spec to be 16 bits. That wasn't because Sony changed their minds about 'the limits of human hearing', it was because they thought they could implement the technology. 30 years later we can implement a bit depth of 24 bits with no problems. According to the Wikipedia article on the history of the Compact Disc (http://en.wikipedia.org/wiki/Compact_Disc http://en.wikipedia.org/wiki/Compact_Disc) the sampling rate was defined for the following reason: "the exact sampling rate of 44.1 kHz was inherited from a method of converting digital audio into an analog video signal for storage on U-matic video tape, which was the most affordable way to transfer data from the recording studio to the CD manufacturer at the time the CD specification was being developed." So again this has absolutely nothing to do with 'the limits of human hearing'. Recording engineers, such as Barry Diament of Soundkeeper Recordings, think that the sound of 24/192 digital matches the output of the live microphone input of their recording desk. Barry Diament doesn't think 16/44.1 is nearly as good. If you buy a recording at a high resolution you can always encode it as an MP3 or ACC so that it fits on your portable player. On the other hand if you buy an MP3 or AAC recording you can't bring back the lost resolution. So if I can fit my entire CD collection onto a cheap 1 TB hard drive, why do we care about how much disk space high resolution 24/96 or 24/192 audio will take up? When you don't have physical media it is trivial for a site to offer a range of resolutions according to the needs of the buyer. If I want 24/96 and someone else is only interested in 128 kps MP3s, then we can both download from the same site and only pay for the quality we need.

ugh 16y ago
If people can’t hear the difference in blind tests all that talk about the supposedly better sound is utterly irrelevant.
- rdale 16y ago
  Why would you value a 'blind test' over what an expert recording engineer, such as Barry Diament, thinks? There are a lot of problems with blind tests, and there has certainly been much discussion about the arguments and counter arguments. If you wheel in a bunch of untrained listeners off the street and get them to listen to recordings they are not familiar with, using a Hi-Fi that they are not familiar with, in stressful un-relaxed circumstances. Why would you expect to get some kind of definitive answer about 16/44.1 vs 24/192 for instance, that somehow trumps the opinion of highly regarded recording engineers?
  - ugh 16y ago
    Evidence trumps authority. I thought that was a basic lesson of science education?
    - rdale 16y ago
      I thought I listed some of the possible flaws in blind tests - there is nothing unscientific about that. If you value the results of any sort of blind test, no matter how badly conducted, over the opinions of recording engineers, then it doesn't seem to be a purely scientific matter to me.
      - ugh 16y ago
        Your methodological criticisms are sound, it‘s just that they don’t seem to apply to the quoted paper (I found the PDF): http://www.mesoscale.nl/aes_article.pdf http://www.mesoscale.nl/aes_article.pdf
        16y ago