Well, I snuck into a Barnes and Noble on the way home from work to read July's
Stereophile... they were out, so I picked up this month's copy of
The Absolute Sound instead. Wow, what a good read... this month's issue is primarily devoted to the debate of DVD-A vs. SACD. (Articles on Hi-Rez audio make Dan happy
) Of course, I was too cheap to pay the $7.95 cover price, so I read it in-store
And, of course, I was too foolish to think that it might be available online (
here, in fact).
Anyway, the main article discussing the pros and cons of DSD (high sampling rate, 1-bit depth) vs. PCM (lower sampling rate, 16- and 20-bit depth). The mainstay of the writer's argument against DSD was, actually, the paper mentioned by Tomcat, written by Lipschitz and Vanderkooy. The reason they dislike DSD, apparently, is that it requires far too much information to eliminate audible noise from a recording algorithm that has such a high sampling rate; in fact, eliminating noise from audio above 50 kHz DSD audio is almost impossible given the amount of space it would take up. Apparently, DVD-A's PCM technology can eliminate noise up to twice as efficiently (in the audible spectrum, as I understood it).
Of course, as the author himself states, few adults can hear frequencies above 20 kHz, and no human can hear above 25 kHz... the reason he thinks it so important that DSD has difficulty eliminating noise above 50 kHz is that he believes it's just another piece of evidence pointing at the inherent and central deficiency of DSD -- no matter how "perfect" you make it, it can never be perfect; aside from that, it takes up too much space.
I wholeheartedly agree that if you use higher and higher sampling rates for DSD, it will still never become perfect. I also agree, as should anyone, that given higher and higher bit-depths and sampling rates for PCM audio, PCM will come closer and closer to "perfect," or life-like, sound. I have always agreed with this.
However, it is important to note that while it's important to judge in terms of future potential of technological paradigms, you can only judge different recording formats by their own merits; in the case of DVD-A, its highest potential of 24/192 audio is still (debatably) worse than SACD's standard DSD audio. And furthermore, the DSD technology used today, in my opinion,
is more sophisticated and closer to real, live sound than the best commercially-available PCM audio available in DVD-A form.
In fact, recording engineer Michael Bishop whose views are also featured in the magazine (and within the page whose URL I gave above), when listening to DSD, DVD-A PCM, and standard redbook (regular CD-style) PCM, decided along with the other engineers present that DSD was clearly more realistic and thus better than DVD-A's PCM.
So, to sum up my argument: while I agree that
in theory PCM has more potential than DSD, I think the technology available today makes SACD's DSD superior in sound to DVD-A's PCM because it is a format fundamentally geared towards media that still don't have the data-storing capacity needed for perfect PCM sound.
Dan