DVD-A vs. SACD


I'm afraid of getting a bunch of "We've already talked about this" rotten tomatoes thrown at me, but there isn't a search function here and I hate scrolling back through old pages.

I have read two slightly contradictory articles on the issue. The first one, here http://www.audiorevolution.com/equip/dvdavssacd/

says SACD is better but only under the circumstance that no DSP is done to the material after recording, which means almost never.
To fill in what he says with a few more facts. Originally DVD-A was going to be 3 channels 24/96 and 3 channels 16/48 in surround mode and 2 channels 24/192 in stereo. The sampling rate of stereo was set so high to keep the bit rate constant. Meridian Lossless Compression came in and made it so all 5 of the main channels could be recorded 24/96. He is right that 24/192 does not increase perceptual sound quality.

The other article
http://sound.westhost.com/cd-sacd-dvda.htm
is scathing towards SACD. But there are a few questions I have.
One, he talks as if the only kind of DACs on the market are bitstream and "multibit." If you look at Burr-brown's product sheets you will see 3 types: DSD (bitstream), delta-sigma (the most common type on middle and high end consumer products), and "advanced segment" which are right in the price range he talks about for "true multibit" DACs.
Similarly, I once read a passing comment on the laserdisc newsgroup that a tech was disappointed when he opened up a MLD-7020 and saw that McIntosh did not replace Pioneer's "bitstream" DACs with true audiophile DACs. Elsewhere I have learned that delta-sigma DACs typically have an internal resolution of 4 bits (from someone who had not studied conumer audio products in many years, however).

Thinking in terms of my own theory, if you take 24/96 and change it into 1 bit oversampled 24 times, I'm not quite sure why that wouldn't work. I see 2 problems. Problem 1 is that SACD is oversampled 29 and 5/30 times. I don't know a theoretical model where that gets you anywhere.

And, I can see how reconstructing a DSD waveform would produce more of a triangle wave rather than a sine wave, since you'd have a bunch of extra data points between the critical points. But I really don't know squat about the hardware implementation of DAC design, so I don't know if it really works like that. And my vision of filling in the gaps with extra data points only works for integer multiple oversampling, so there are some things I am not seeing.
128x128dnewhous

Showing 3 responses by dnewhous

If Vinyl is so perfect, why does reel to reel tape sound better? An analog medium has imperfections and imprecision as well. Vinyl is better than CD, but not DVD-A. And even on moderately priced gear (like my PC) DVD-A makes a difference.

And if I ever get audiophile grade electronic equipment, it will be Meridian.
Someone brings up another totally 100% valid point that renders a lot of this theoretical hooey.

How good a job are the record companies doing with the mastering process?

For instance, I just got a gold CD of Pink Floyd's the wall. I also have EXOES, their new greatest hits collection. It says in there that they did a 24/96 remastering. Well, comparing the songs they have in common, the gold disc sounds better.

As to whether something is direct to digital - even in this day and age, most music isn't, but much is. Look at the CD and see if you can see "AAD" "ADD" or "DDD". The first refers to the original studio recording, the 2nd to the mastering, and the 3rd to the CD itself. Most CDs don't state this information. There is also the oddball "DAD" CD.

At the end of vinyls lifetime, some vinyl was touted as digitally mastered, as though that were supposed to be superior. (I don't have enough experience myself to vouch for digitall versus analog mastered vinyl.)

The digital masters they were using could not have been any better than DVD-A quality, and it follows from this logically that vinyl is inferior to DVD-A.
Time for me to eat crow here - I just looked at the back of one of my "ultradiscs" (gold CD) again and it says analog analog digital. So the analog mastered ultradisc sounds better than the newer 24/96 mastered greatest hits CD.