Human hearing and standard CD Vs. SACD / DVD-A

Re subject, some interesting info that I came across today...

As to human hearing and the supposed benefits of much higher sampling rates (48 kHz, 96 kHz and higher vs. the standard CD rate of 44.1 khz/16-bit) yes, you are correct. There isn't any point, because the conventional 44.1 kHz sampling rate of standard CD recordings will fully cover the uppermost limits of human hearing. Indeed, after our teen years, most males can't hear anything above 15 kHz. Not that it matters, because there is little or no musical information of importance in those ultra-high frequencies.

The best DVD-A and SACD recordings sound better to many enthusiasts because much greater care is taken in the recording and engineering. Some engineers report that the studio noise floor is improved, which one might expect from a 24-bit recording because each "bit" adds 6 dB of improved signal-to-noise ratio, so a 24-bit recording has a theoretical range of 24 X 6 = 144 dB, compared to CD's 16 bits (96 dB). These formats also permit a bigger dynamic range, but even here, conventional CD will cover the audible dynamic range of the most extreme orchestral or instrumental dynamics. Still, there is a consensus that on SACDs and DVD-A's, miking is superior to accommodate the higher bit rate and number of bits and this trend shouldn't be discouraged.

One fascinating study presented at a recent meeting of the Audio Engineering Society by E. Brad Meyer and David R. Moran, longtime audio enthusiasts and members of the Boston Audio Society, showed that listeners were unable to detect the presence of a 44.1-kHz, 16-bit A-to-D and D-to-A converter when it was inserted as a “filter” in the two-channel analog output from a high-end DVD-A/SACD player. (DVD-Audio uses a 192-kHz/24-bit PCM system and SACD uses Sony’s 1-bit/2.8442 MHz “Direct Stream Digital” system.) The results of the study are published in the Journal of the Audio Engineering Society, September 2007 (Volume 55, Number 9). After hundreds of double-blind listening comparisons, the test subjects who participated were unable to distinguish any change in the SACD or DVD-Audio signals when they were “filtered” by the standard two-channel 16-bit/44.1-kHz CD system, which means that imposing a 44.1-kHz sampling rate and 16-bit dynamic range onto the SACD/DVD-Audio signals in no way degraded the music signals.

This rather controversial study nevertheless confirms my own experience in a casual listening experiment performed in the mixing studios of Chesky Records (co-owner and composer/producer, David Chesky, is a friend) in New York. There were six of us present, all senior editors and writers about sound and recording, and none of us could reliably identify or distinguish 44.1 kHz/16-bit from 96 kHz or higher (24-bit) recordings using identical music sources.

Good article Srinivas, and a useful one for those who have a confusion choosing a CD or SACD Player. Even in our own experience many of us could not find the difference between a SACD and CD recordings. I have heard Shangari-la by Mark Knopfler in SACD as well as CD and could not find any difference. I was using Marantz SA7001 as Source.

regards

I have switched back and forth between SACD (2 channel) and CD on the same disc and the difference is very clearly distinguishable. BUT I could not make out any difference between a seperate SACD (2 channel) and CD of the same title.

I have a feeling that they deliberately make the SACD sound better on a multi layer (SACD + CD) disc to help marketing SACD's.

The only place where ppl would prefer SACD would be for 5 channel music but I personally prefer music in good old stereo.

I strongly prefer SACD for ONE very important reason. No, I myself can barely hear any real difference between CD and SACD and I suspect what I hear might be a placebo effect. But there is a distinct advantage to SACD. As you know, SACD offers far higher dynamic range than CD (over 120db). This automatically eliminates the possibility, or rather the need, for compression of any kind -- and also takes care of the problem of clipping. Now, one assumes that labels are transferring material from a pristine source such as the original master reel else this advantage is lost.

As for actual difference in quality I am still undecided. At least one friend, with exceptionally good hearing and whom I trust completely, claims there is a (positive) difference and the sound is a bit closer to warm analog than CDs. But for me the knowledge that I won't have to hear the likes of Oasis' (Whats The Story) Morning Glory stabbing at my eardrums is good enough.

Can you or can't you hear a difference? If you can't then where is the question of higher dynamic range, distinct advantage or strong preference?

You can't have a strong preference for something only because it's 'better' on paper. The differences whether good or bad, have to be audible, definable and distinguishable.

I have stated something completely different. I said that there may not be a perceptible difference in audio quality BUT due to the DSD mastering process (for SACD), the higher dynamic range (i.e. more headroom) ensures that the waveform does not clip and that methods like compression cannot be used to ruin the sound. THIS is what I was referring to -- the fact that we are assured of the absence of these terrible artifacts is good enough for me. To put it very plainly, even if an SACD sounds only slightly better than a CD, I prefer it because I know that I won't be subjected to the harshness that clipping and compression manifest. Hope this clears up my point of view.

I'm confused.. so you prefer it based on theory, even though you practically cannot hear a difference?

I have been listening to CD's for a long long time and I don't think I can say that I have been subjected to any "harshness that clipping and compression manifest".. But, if you're happy.. it's great!

Theory apart,I for one find a huge difference between RBCD and SACD's.
Have actually been blind tested on RBCD and SACD of the same title and have always been able to tell the difference. Like everything else in audio
the quality of the SACD player makes a difference.

Hi,

I have not spent much time with SACD,but I do find HDCDs tobe better than regular CDs due to two reasons:

- The dynamic range is more. This has an impact on western classical recordings where 20 violins playing together do sound 20 times louder than when only one is playing. Same applys to the choir too. If you are used to pop/movie soundtracs, where the chorus sounds only as loud as the lead singer, you would not hear this difference. Also for vocal solo songs where the singer sometime whispering and sometimes singin at full voulme, you would not get that delecate whisper on regular CDs.

- The fact that this is an HDCD recording ensures that there is a sincere effort involved. They just do a better job at mastering. The same applies to XRCDs, which are technically no diffrerent from the regular CDs, but always sound better.

Thanks,
Sharad

I have heard many hybrid SACD/ CD disc but could not make huge difference (SACD feels slightly warm & less harsh). But my Amp & speakers donot support beyond 20Khz. Has any one heard with Amp & Speakers supporting frequency beyond 20 Khz so that perception of those frequencies which is supposed to provide live ambience is enjoyed ?.
In any case I enjoy SACD as it gives a psychological satisfaction of hearing the best digital format. I agree with the originator of this article in this regard.