However, since the Philips literature had specifically referenced DVD-Audio in its comparison, Anderson next examined the PCM output at DVD-Audio’s higher resolution sample rates. Here, the graphs told a very different story. The 96kHz trace (shown in Figure 3, right) improved in rise time, resulting in a sustained peak duration much closer in appearance to a square wave.
Anderson explained that the bump at the peak’s extremities is the signal’s first harmonic, now identifiable thanks to the increased sampling precision. At 192kHz (Figure 4, right), Anderson reports, the trace improves even more, cutting the rise time in half and revealing the square wave’s third harmonic.
Turning to the DSD trace (Figure 5, right), Anderson found that “The DSD trace does look very similar to the picture in the Phillips brochure, and represents the square wave better than the first two PCM traces [at 44.1 and 96 kHz].” But when compared with 192kHz PCM, DSD performance proved very similar.
Overlaying the DSD and 192 kHz traces (Figure 6, right), Anderson pointed out that the difference in rise time between DSD and 192 kHz are “statistically (and perhaps audibly) insignificant.” Also, both accurately extract the first and third harmonics from the square wave. However, Anderson noted one readily apparent difference between DSD and the highest resolution PCM – the DSD trace is blurry.
The DSD trace, Anderson points out, is tainted by DSD’s dirty little secret: the excessive amount of noise created by one-bit sampling. To disguise it, Sony and Philips implemented a noise-shaping system that shifts noise from the lower frequencies into the ultrasonic range, where it is presumably inaudible (a debatable point in itself, Anderson maintains).
However, Anderson attributes the primary cause of the DSD “blurring” shown in Figures 5 and 6 to imprecise traces along the vertical and horizontal axes, which are much more significant than any noise superimposed on the traces themselves. He suggests these imperfections in the DSD signal are evidence of imperfections in amplitude and time domain, respectively. “Were one to zoom in on the DSD signal,” he said, “one would actually see amplitude fluctuations of 50% peak amplitude, and time domain errors similar to the 96kHz rise time deviation. The defect, when compared with the PCM photos, illustrates perfectly the reason that DSD is incapable of reproducing the same transient twice.”
What can we draw from these findings? Anderson was quick to point out that a square wave is not the most pleasurable or representative musical experience (as anyone who’s ever heard one can readily attest). However, it does provide a “torture test” yardstick. In testing one of the DSD proponents’ key marketing claims, Anderson concluded, “We can clearly see that with this particular waveform, PCM produces a much more faithful copy of the original with both accuracy and precision. It does help dispel the myth that DSD’s one-bit sampling is the panacea to the world of digital audio.”Geez, I wish there were more 192-kHz DVD-Audio discs available. :frowning:
So, what would 384 kHz PCM look like?
the strictly pro-SACD crowd does not know what it is missing by simply blowing off DVD-AThis is not a fair comment as most Super Audio fans I know also have DVDA players. I even record in hi-rez PCM at 88.2khz. It sounds great on classical work, but not as good as DSD does.
I think the best one can do, and I say this with a diplomatic perspective, is listen to each format for oneself and decide what you like.Which agrees COMPLETELY with what I wrote. Thanks for backing up my statement.
Anyway, it's funny to disregard measurements and go with what "sounds good". I'll bet you that the engineering teams behind DSD and hi-rez PCM both payed CLOSE attention to the measurements. But once it's ouside of the lab the measurements are less important I guess.
Tests like this don't matter to the SACD proponents. To them it's all "how it sounds", accuracy and science is secondary if it "sounds good".Sounds a lot like like the age-old Tube versus SS argument.
But try getting any Tube or DSD proponent to admit that the sound that they find 'more musical' just might be less accurate.
Still, it would be nice to know what model of 'scope was used for the tests.
Children, if I hear anymore fighting, I will have to separate you into two separate rooms, just like the kids in Audio Asylum!
