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.
A Possible Reason for SACD to be Superior
I have recently been trying to compare the SACD format to Redbook on my system and have discovered that the SACD layer on the disk seems to always be recorded at a lower volume making an A/B comparison extremely difficult because while switching layers on the disk isn't too difficult, matching relative volumes is and comparing the sounds at the same volumes is key to any comparison.
What I did realize, however, is that this means that the SACD signal isn't as attenuated (is that the right word?) as much by the preamp to obtain the same volume. Shouldn't this be preferred? If I understand my EE friend correctly, and I often misunderstand him, the ideal situation is for the signal to pass through the preamp without attenuation which means 0 db on a piece of equipment that give volume readings in -dB. From this perspective it seems that SACD should have the advantage.
What I did realize, however, is that this means that the SACD signal isn't as attenuated (is that the right word?) as much by the preamp to obtain the same volume. Shouldn't this be preferred? If I understand my EE friend correctly, and I often misunderstand him, the ideal situation is for the signal to pass through the preamp without attenuation which means 0 db on a piece of equipment that give volume readings in -dB. From this perspective it seems that SACD should have the advantage.