These days, PCM originates in a multi-bit SDM. John Siau Wrong conclusion for the reasons outlined above. In that way the discussion is not coloured by any post-processing of the signal, which in any case is not possible in the native DSD domain.” Of course, those arguments apply only to ‘purist’ recordings, which seek to capture the microphone output as naturally as possible. the output of an SDM) will not deliver the full bit depth that he offers up as a key distinguishing feature of 24/96. I’ll also point out that his argument suggests that DSD (i.e. AIX to suggest that 24/96 PCM is inherently better than DSD, since DSD comes directly out of a SDM in its native form, whereas PCM is derived through digital manipulation of an SDM output with, among other things, a ‘brick-wall’ filter with a less-than-optimal configuration. What’s to debate?īitPerfect: “So, from the foregoing, purely from a logical point of view, it seems somewhat contradictory for Dr. While those using PCM to record and deliver high-end audio can provide the exact master file from the studio to the consumer without any conversions (and the loss of information associated with them), at a lower price, in a smaller file, and with extended fidelity. ![]() They allow the ultrasonic noise…the uncorrelated, non-harmonic noise…to remain along with any ultrasonic music components (and yes, there are money up to and beyond 40 kHz) until a 30 kHz corner frequency lowpass filter kicks in. Thanks for that one John.Īs we read the last paragraphs from the BitPerfect article, Richard acknowledges the BitPerfect’s DSD Master makes “design compromises” in order to craft a viable product for listening to PCM and DSD music files. And there would be yet another filter for the DSD 256 files. ![]() And I had no idea the higher rate DSD encoding requires independent analog lowpass filters to get rid of the ultrasonic noise. AIX I thoroughly enjoy learning new things. Given the complexity of these DSD post filters, I doubt that there will be many playback devices that offer switchable filters.ĭr. This means that a disk player or DAC needs to have switchable analog lowpass filters in order to fully benefit from DSD128. The complication is that DSD128 and DSD64 need different analog lowpass filters. The low pass filter can be moved up in frequency by a factor of 2. John Siau I agree that the ultrasonic noise problem is less of an issue with DSD128, but it still needs to be filtered out. The problem with ultrasonic noise pretty much goes away with DSD128 and above, something I have also written about in detail in a previous post.” In our view, this means that design choices will be made which do not necessary coincide with the best possible sound quality.Īs a final point, all the above observations are specific to ‘regular’ DSD (aka ‘DSD64’). But if a similar functionality is being designed for the internal conversion stage of a PCM SDM-ADC then we know that a residual ultrasonic noise peak in the output data is not going to be acceptable. ![]() And it shouldn’t happen.īitPerfect: “In designing DSD Master, we make those design compromises on the basis that the purpose of these conversions is to be used for final listening purposes. They’ll stick to the “DSD is warmer and sounds more like analog” theme and keep dreaming that DSD is going to take over the world of audio production. Plenty of audiophiles, download sites, equipment manufacturers, and audio publications will remain faithful believers and won’t even bother to consider the information presented on this site and others. This does not close the issue of DSD and 1-bit encoding in general. The last five days have unambiguously established that high-res PCM trumps DSD. My view is that Richard called me out and accused me of contradictions, and playing fast and loose with the “facts” with regards to the simple statement that 96 kHz/24-bit PCM provides more audio accurate recording and reproduction than a DSD 64 recording of the same source. ![]() Some comments have positioned this conversation as a debate on a philosophical subject. I couldn’t refute the misrepresentations of Richard from BitPerfect without John Siau’s assistance. I felt it was important to clear away some of the smoke and misinformation and present accurate information from a very knowledgeable analog and digital audio product designer. So thanks for hanging in there for the last 5 days.
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