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Very interesting article. However, this is false: “ that’s why CD music had a sample rate of 22000 Hz. Modern sound cards however tend to use sampling rates t

Very interesting article. However, this is false: “ that’s why CD music had a sample rate of 22000 Hz. Modern sound cards however tend to use sampling rates twice as high - 44100 Hz or 48000 Hz” CDs are/were 44100 hz, they were never 22000, because you need two samples per wave and because you need slight over sampling and to make the conversion from 48k in to bad math to discourage DAT machine as a lossless copy format for the masses.

MaxBarraclough 6y ago
> you need slight over sampling and to make the conversion from 48k in to bad math to discourage DAT machine as a lossless copy format for the masses What do you mean by this?
- whiddershins 6y ago
  I might be wrong about the 48k vs 44.1k thing. My impression is that the difference in sample rate between the formats was some sort of attempt to discourage lossless copying of published music. Recall that we couldn’t just throw it on a computer and resample it back then. But regardless, you need to slightly over sample when doing A/D conversion because you need to do a very strong low pass filter before you hit the sample rate to avoid harmonic distortion. So you need the filter to be some amount higher than the target maximum reproduced frequency, because the filter is in the analog domain and itself introduces audible artifacts. So you must sample at a higher frequency than you intend target. 48k makes sense because you have more ‘extra’ frequencies to work with, so it’s easier to get the filtering out of the audible space.
  - Jasper_ 6y ago
    Converting from 44.1k to 48k is lossless, and has always been. Converting from 48k to 44.1k is practically lossless: You lose frequencies above 28KHz, but that's about the range at which human hearing drops off anyway. > Recall that we couldn’t just throw it on a computer and resample it back then. Of course you could. How else do you think CDs were mastered and produced? The CD was developed with the idea of using it on computers, and for computer storage. And if, in practice, someone wanted to copy it, they'd just record the CD to tape using analog out (not quite lossless, but nobody cared back then), or copy CD/CD with no resampling required. The 44.1k is a mostly historical accident, and it goes back to the Red Book CD audio spec being reused from an earlier project for digital audio that Sony was working on, the U-matic, where 44.1k was basically how much audio would fit evenly into some number of lines in the tape's storage.
    - whiddershins 6y ago
      You may be correct about the origins of 44.1, sounds plausible. I don’t think we are aiming at the same concept. I was there, as perhaps you were too. Average consumers did not posses, could not afford, technology to duplicate CDs easily or to convert a CD to DAT. I can’t recall all this after so much time has passed, but the gist is that somehow the record industry influenced the deployment of technology to reduce lossless duplication ability for consumers. It wasn’t until home computers became so fast and ubiquitous that this changed.
detaro 6y ago
DAT has no influence on how CD rate was choosen, because DAT came after CDs (but at least early DAT recorders indeed didn't allow digital sources to be recorded at 44,1 kHz due to music industry pressure, and later copy protection mechanisms were added)

MaxBarraclough 6y ago

> you need slight over sampling and to make the conversion from 48k in to bad math to discourage DAT machine as a lossless copy format for the masses What do you mean by this?

whiddershins 6y ago
I might be wrong about the 48k vs 44.1k thing. My impression is that the difference in sample rate between the formats was some sort of attempt to discourage lossless copying of published music. Recall that we couldn’t just throw it on a computer and resample it back then. But regardless, you need to slightly over sample when doing A/D conversion because you need to do a very strong low pass filter before you hit the sample rate to avoid harmonic distortion. So you need the filter to be some amount higher than the target maximum reproduced frequency, because the filter is in the analog domain and itself introduces audible artifacts. So you must sample at a higher frequency than you intend target. 48k makes sense because you have more ‘extra’ frequencies to work with, so it’s easier to get the filtering out of the audible space.
- Jasper_ 6y ago
  Converting from 44.1k to 48k is lossless, and has always been. Converting from 48k to 44.1k is practically lossless: You lose frequencies above 28KHz, but that's about the range at which human hearing drops off anyway. > Recall that we couldn’t just throw it on a computer and resample it back then. Of course you could. How else do you think CDs were mastered and produced? The CD was developed with the idea of using it on computers, and for computer storage. And if, in practice, someone wanted to copy it, they'd just record the CD to tape using analog out (not quite lossless, but nobody cared back then), or copy CD/CD with no resampling required. The 44.1k is a mostly historical accident, and it goes back to the Red Book CD audio spec being reused from an earlier project for digital audio that Sony was working on, the U-matic, where 44.1k was basically how much audio would fit evenly into some number of lines in the tape's storage.
  - whiddershins 6y ago
    You may be correct about the origins of 44.1, sounds plausible. I don’t think we are aiming at the same concept. I was there, as perhaps you were too. Average consumers did not posses, could not afford, technology to duplicate CDs easily or to convert a CD to DAT. I can’t recall all this after so much time has passed, but the gist is that somehow the record industry influenced the deployment of technology to reduce lossless duplication ability for consumers. It wasn’t until home computers became so fast and ubiquitous that this changed.

detaro 6y ago

DAT has no influence on how CD rate was choosen, because DAT came after CDs (but at least early DAT recorders indeed didn't allow digital sources to be recorded at 44,1 kHz due to music industry pressure, and later copy protection mechanisms were added)