A Possible Reason for SACD to be Superior

In spite of different output levels source material could be recorded with the same compression. It is difficult to compare CD to SACD since they are completely different but just looking at the bit rate coming out of both we can judge about quality. CD output rate is 1.4MHz while SACD output at 5.6MHz. In addition, because of very nature of Sigma-Delta converters antialias filters in front of the converter are set to much higher frequency allowing recordings with better pulse response. It also shows in extended bandwidth (50kHz vs. 20kHz). SACD output stream is very similar to amplifiers class D operation (Pulse Width Modulation) and needs very simple converter to make average values. Quantization noise is moved up to non-audible band. Overall dynamic range is higher(105dB vs 96dB).

Kijanki - So why do you think it is that something like SACD, that from a technical aspect should be superior like other high resolution formats are considered to be, doesn't seem to be supported much in the audiophile world? Neither of the audio store locally do anything with SACD.

SACD converters, operating as Pulse Width Modulation are difficult to implement in computer servers - increasingly popular. Strong copy protection would not be the reason, since most of people are honest, but combined with initial price of SACD and inability to make backup killed the format. In my opinion, there should be incentives to establish new format but instead greed won and $30+ SACDs were not very popular at the beginning, not to mention cost of SACD players.

Perhaps they don't even care about audio quality, since most of people are happy with MP3, but rather tried to introduce strong copy protection (impossible to copy SACD) to fail at the end.

44.1 kHz sampling of CD is not enough. Nyquist says it is for 20 kHz audio bandwidth but Nyquist theorem applies only to continuous waves. The shorter high frequency sound the worst reproduction it is (cymbals, percussion etc.).

SACD has both more dynamic range and greater frequency response (numerically up to 100kHz, functionally to 50kHz under most conditions). It also uses a different encoding system (1 bit DSD versus 16 bit PCM in CD Red Book), which theoretically misses less information. Most consumers aren't familiar enough with audio to hear the difference, which is big reason why SACD became a market failure. Higher cost + iron-clad copy restriction + no apparent benefit = failure. Too bad, because i can clearly hear the difference in my system. SACD is much more listenable.

Going back to part of my original question, if two recordings were identical with the exception of the output level, would it be expected that the one with the lower output would sound better when played at an equal volume?

My answer will be No, since the lower output level recording will not be utilizing the full dynamic range of the given format - CD, SACD, DVD-A, etc.

For example, the CD has 16 bits resolution. The CD that sounds louder, than the other, will be utilizing almost all 16 bits (for example), and the one that has lower output level, will be utilizing less bits. However, it is really up to the mastering engineer what the end result will be.

Please note that CD (PCM) and SACD (DSD) has nothing to do with each other, and the lower level with SACD does not mean it is inferior to CD, on the contrary, SACD is much better than CD in any case, IMO (except if audio recording engineer didn't know what he/she's doing :)).

Also, please note that an HDCD without HDCD decoder will also sound 6dB lower that a regular CD.

CD and SACD are just two different formats, requiring different type of processing, that has nothing to do with output level and actual resolution.

Hope this helps!

Alex Peychev