[khaos974]

Quote:

 
So I've been reading some papers and the Meyer & Moran one costs $20 what's up with that - https://secure.aes.org/forum/pubs/journal/?ID=2
 
Anyway... in the introduction it says "The noise of the CD-quality loop was audible only at very elevated levels."
 
So, they are saying, that even with very sophisticated A/D/A equipment (HHB CDR850 Professional), the duplicate CD had audible noise to the participants?
 
Note, they made a duplicate CD for testing purposes, this is not the same as A/B/X'ing whether there is an A/D/A in the listening chain or not, as far as the theoretical total transparency of a DAC is concerned, that should be self-evident.

It really depends what very elevated levels mean, it's quite obvious that if you record a mosquito flying on a CD and then play it back at +90 dB gain, the noise would be absolutely audible.

 

[kiteki]

 
That's true, but there should be no new mosquito sounds in an A->D->A process. ^^
 
If high-end ADC/DAC is totally transparent, you should be able to do A->D->A->D->A->D->A->D->A->D->A->D->A and hear no difference.
 
Anyway, the new CD X after such a conversion, will still be played with the same equipment as CD Y.
 

 

[Zeebra]

Quote:

Here, here!  When CDs first came out they sounded awful because the DACs and filters used were horrible.  It was a new technology so digital didn't live up to the hype in the ears of those who knew what superior reproduction was supposed to sound like.  But that was 30 years ago and digital has come a LONG way.  With a good digital source and DAC there is no need to deal with the pops and clicks, but people still stand by their love of vinyl and there's nothing wrong with that if it makes them happy.  I could never deal with it though.
 

In my opinion this is a sensible and down-to-earth explanation to the phenomena. The argument is usually tiresome because people throw around incorrect metaphors to describe analog's superiority.
 
The way PurpleAngel put it: wave > wave > wave would only make sense if the analog domain, tapes and vinyl wasn't so prone to errors, if vinyl pressing/carving methods were infinitely precise, and if they weren't limited in dynamic range during playback due to physical limitations in equipment (in ideal cases about 70dB). If anything, digital copies are perfect time after time as far as the content saved in them stays within the Nyquist frequency, they don't warp or get demagnetized, and the only thing limiting your dynamic range is the bit depth (90dB with 16-bit files, way more with 24-bit) and the quality of your DAC and amplifier (even with consumer products, very likely superior to an average LP consumer system).
 
I would argue even with my very limited amount of knowledge that the human ear is way too insensitive to errors and in sample decimation and the such, that anyone could say analog is superior. It just doesn't make sense.. "to me" as people have the habit of saying when it comes to audio

 

[germanium]

Quote:

In my opinion this is a sensible and down-to-earth explanation to the phenomena. The argument is usually tiresome because people throw around incorrect metaphors to describe analog's superiority.
 
The way PurpleAngel put it: wave > wave > wave would only make sense if the analog domain, tapes and vinyl wasn't so prone to errors, if vinyl pressing/carving methods were infinitely precise, and if they weren't limited in dynamic range during playback due to physical limitations in equipment (in ideal cases about 70dB). If anything, digital copies are perfect time after time as far as the content saved in them stays within the Nyquist frequency, they don't warp or get demagnetized, and the only thing limiting your dynamic range is the bit depth (90dB with 16-bit files, way more with 24-bit) and the quality of your DAC and amplifier (even with consumer products, very likely superior to an average LP consumer system).
 
I would argue even with my very limited amount of knowledge that the human ear is way too insensitive to errors and in sample decimation and the such, that anyone could say analog is superior. It just doesn't make sense.. "to me" as people have the habit of saying when it comes to audio

Usable dynamic range with digital even with the best of modern DACs is actually only 75-80db before horrible distortion becomes appearant with 16 bit audio. 24 bit audio is limited by the noise level of the analog section of the converter & amps following the converter which in best case so far is in the 130db range. By this point you would start to hear the same type distortion present in the 16 bit system if it weren't covered up by noise of the analog section assuming perfect noise free input to the 24 bit system in recording which is impossable.
 

 

[jcx]

never heard of dither? - it really works, pretty universally used for CD mastering
 
poke thru http://audio.rightmark.org/lukin/dither/dither.htm site, find, listen to the exagerated 8 bit truncation vs dither examples

 

[germanium]

Quote:

never heard of dither? - it really works, pretty universally used for CD mastering
 
poke thru http://audio.rightmark.org/lukin/dither/dither.htm site, find, listen to the exagerated 8 bit truncation vs dither examples

Yes I know very much about dither & its usefullness at reducing distortion however it does this at the expense of increased noise which still limits your signal to noise ratio to about 84db though at least now you could record into the noise floor where you couldn't before. Granted I was talking before without the added benefits of dither. I have even experimented with different types of dither in my past so I'm definately very aware of it. I was intentionally talking of the raw 16 bit system without any work arounds compared to the raw 24 bit system & ultimately to the raw analog system which doesn't look so bad when compared to the raw 16 bit system as originally speced.
 

 

[jcx]

wrong - tpdf dither gives 93 dB with 16 bits - way ahead of vinyl, analog master tape
 
noise shaped dithers do even better on perceived S/N
 
there is no reason to even consider undithered 16 bits today - the dithering from 24 bit source is a button/menu item on every digital mastering tool made today
 
making claims of CD audio limits based on rounded/truncated 16 word reduction is a "strawman" - doesn't represent "best practice" or even typical digital mastering for decade(s?) now
 
 

 

[Zeebra]

Quote:

Usable dynamic range with digital even with the best of modern DACs is actually only 75-80db before horrible distortion becomes appearant with 16 bit audio. 24 bit audio is limited by the noise level of the analog section of the converter & amps following the converter which in best case so far is in the 130db range. By this point you would start to hear the same type distortion present in the 16 bit system if it weren't covered up by noise of the analog section assuming perfect noise free input to the 24 bit system in recording which is impossable.
 

Then again I personally listen at relatively low volume levels, so the noise floor and small amounts of distortion that comes from DAC and quantization errors is very much unobservable to me.. I do understand this is a poor and subjective defense much akin to the ones analog enthusiast use, and not legit when we get to the scientific arguing. I'd be very interested to learn about both the science and subjective results, point of diminishing returns and redundancy when it comes to playback and storage of audio though, so I think I'll sub and stick around.

If I recall correctly, the best ACD and DACs in the scientific tools are about 120dB or slightly greater, and the Benchmark DAC1 is 113dB or so. But as I said I doubt anybody listens at those levels, so I wouldn't ever need such good equipment, I'm in zen if my system pushes about 80dB comfortably, has a flat frequency response and doesn't have audible noise floor, which is very modest and possible with both analog and digital domains nowadays

 

[germanium]

Quote:

wrong - tpdf dither gives 93 dB with 16 bits - way ahead of vinyl, analog master tape
 
noise shaped dithers do even better on perceived S/N
 
there is no reason to even consider undithered 16 bits today - the dithering from 24 bit source is a button/menu item on every digital mastering tool made today
 
making claims of CD audio limits based on rounded/truncated 16 word reduction is a "strawman" - doesn't represent "best practice" or even typical digital mastering for decade(s?) now
 
 

Dithered noise level of standard non noise shaped dither uses 2 lowest bits which limits you to 84 db S/N ratio. This is real & percieved. Noise shaped dither uses even more bits which further limits S/N ratio but actually seems quieter due to the noise shaping. Yes I have done the experiments so I know what I'm talking about. You cannot get 93 db S/N ratio with dither on a 16 bit system. While dither does allow recording into the noise floor but so does analog & analog is speced down to the noise floor & so should digital be. That makes them comparable & as such A S/N ratio of 84 db is sufficient for 16 bit digital audio with non noise shaped dither.No need to hype it up like you are doing. The early hype of 96db S/N ratio was just that. HYPE. It wasn't actually usable by any stretch of the imagination as originally designed.
 
I will admit though that my original statement does not take into account best case modern pratice but it wasn't intended to. It was intended to expose the raw deficiencies of the original 16 bitspec which even modern DACs by themselves cannot completely overcome even still. They still need the bandaid of dither to perform thier best.
 

 

[germanium]

Quote:

Then again I personally listen at relatively low volume levels, so the noise floor and small amounts of distortion that comes from DAC and quantization errors is very much unobservable to me.. I do understand this is a poor and subjective defense much akin to the ones analog enthusiast use, and not legit when we get to the scientific arguing. I'd be very interested to learn about both the science and subjective results, point of diminishing returns and redundancy when it comes to playback and storage of audio though, so I think I'll sub and stick around.

If I recall correctly, the best ACD and DACs in the scientific tools are about 120dB or slightly greater, and the Benchmark DAC1 is 113dB or so. But as I said I doubt anybody listens at those levels, so I wouldn't ever need such good equipment, I'm in zen if my system pushes about 80dB comfortably, has a flat frequency response and doesn't have audible noise floor, which is very modest and possible with both analog and digital domains nowadays

You are a wise man as all this scientific stuff is actually meaningless at low volume levels especially if you are using an analog volume control. I use digital control but convert the sound to 24 bit so distortion is not a factor at low volumes here either. I listen somwhat louder than you though, about 85-90db average to get sound that is flat to my ears.
 

 

[stv014]

Quote:

Dithered noise level of standard non noise shaped dither uses 2 lowest bits which limits you to 84 db S/N ratio.

 
84 dB does not seem to be correct, and using the two lowest bits may just mean a peak noise amplitude of +/- 2, rather than an RMS level of -84 dBFS. Furthermore, analog noise is usually specified as an A-weighted value, so the same should be done to dither noise as well for a fair comparison. Even a simple dither has better than 96 dB A-weighted SNR relative to a 1 kHz sine wave at 0 dBFS.
 

 

[Zeebra]

Quote:

You are a wise man as all this scientific stuff is actually meaningless at low volume levels especially if you are using an analog volume control. I use digital control but convert the sound to 24 bit so distortion is not a factor at low volumes here either. I listen somwhat louder than you though, about 85-90db average to get sound that is flat to my ears.
 

Why thank you. I've got a 24-bit/96KHz interface headed my way too, namely the M-Audio Fast Track Pro, so next up is taking it to an oscillator and signal generator at my university, then doing some acoustic treatment with a measurement microphone in my dorm room with it, and of course finding out should I start using 24-bit upscaling and digital volume control. Then again the interface does have a convenient analog knob so I could just go with that. Well, anything is an improvement from the present and it's mainly to quench my infinite curiosity and get some hands on knowledge on measurements and the such. ENOB and dynamic range will most likely be interesting figures to find out!
 
On-topic: Isn't it a bit ironic that vinyl mastering has in some (or most?) cases more dynamic range than digitally distributed tracks?
  Whatever the case I think people should first hand think of their listening levels and that would they be better off worrying about their speakers/headphones performance than their preferred mediums, doesn't the discussion become redundant if the mediums respective faults are well beyond the tolerance of individual's hearing?

 

[Head Injury]

Quote:

doesn't the discussion become redundant if the mediums respective faults are well beyond the tolerance of individual's hearing?

Not really, since so many are convinced vinyl is inherently superior and digital is inherently flawed. So long as people have the wrong idea, discussion should exist.

 

[Zeebra]

Not really, since so many are convinced vinyl is inherently superior and digital is inherently flawed. So long as people have the wrong idea, discussion should exist.

I hear you, sugarcube. it's relatively frustrating to see everypony discredit digital while it's a much more stable medium. I was mainly referring to the individual's quest to a sound playback system that's good enough for themselves. Then again I suspect many people go way beyond that point in belief of something better, mostly due to misinformation sighted- and confirmation bias etc. So yes I agree with you.

 

[EthanWiner]

Quote:

So, they are saying, that even with very sophisticated A/D/A equipment (HHB CDR850 Professional), the duplicate CD had audible noise to the participants?

No, they're saying that nobody could hear the noise unless the playback volume was raised unnaturally high. Which obviously they did only during quiet or silent portions. If you raise the playback volume of 16-bit audio loud enough to hear the inherent noise of the medium, then playing music will blow out your speakers.
 
BTW, even though the original AES paper costs $20 for non-members, this site explains a lot about the tests:
 
http://www.bostonaudiosociety.org/explanation.htm
 
--Ethan