XRCD is not steganographic in the sense that we are disscusing, but merely a very carefully done 24 bit master mastered down to the normal 16x44 of CD. They also pay very careful attention to the physical manufacturing of the disc, and use aluminum as the "substrate" (instead of the normal audiophile gold).
HDCD is a whole different ballgame, however. It indeed uses subcoded information and a form of spread-spectrum to add something like 1.5 bits of additional resolution to standard CDs. Played back on an HDCD-compatible player or DAC (there are plenty on the market now), the sound quality is noticeably superior, depending on the recording. (A good example is "Perishable Fruit" by Patty Larkin.) Peter Madnick (who was the desginer of the Audio Alchemy stuff) once told me that he used the HDCD DAC chip simply because it had the best filter characteristics of any chip available off-the-shelf. Conversely, HDCD recordings supposedly sound better even on non-HDCD-capable DACs for a similar reason. The odd thing is that Pacific Microsonics (who own HDCD) demands that all CD players or DACs that use the chip attenuate non-HDCD recordings by 3 dB. This is because HDCD recordings are on average 3dB quieter than their non-HDCD counterparts so that they appear to sound better in showrooms (it's well known that volume can give their appearence of superior sound quality). Forunately, they do also allow the manufacturer to include a attenuation-defeat feature so that the customer can defeat it at home (a lot of us believe that anything in the sound chain that is unnecessary is bad). (I've got such a feature on my Levinson DAC.) As for hearing the subcode, I can, on some recordings, but then again my dad folks and brothers are all pro musicians (yes, I claim to have golden ears). It's extremely hard to hear, and results in a VERY low level buzziness on some instruments and vocals. Over all, however, it's great. Go get the newer HDCD "Red" Remaster by King Crimson and compare it to the older non-HDCD master on and HDCD deck. You hear all sorts of details that you never could before. _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
