what is the diff with SACD and HDCD ??

the HDCD system consists of an up-graded encoding and decoding process that was designed to improve CD sonics. If I remember right, HDCD stands for "High Definition Compatible Digital". It is several years old now, and most CD producers have not used it. Also, HDCD requires software in the CD player/DAC to decode it. Standard CD players can play HDCD discs, but of course they don't get the benefits of the HDCD encoding. My DAC does decode HDCD, and I think it is worthwhile, but then I don't have non-HDCD discs to compare it to.

SACD is a totally different, and newer, digital process and is supposed to be a (significant?) improvement over standard CDs. SACD discs have about 7 times more storage capacity than standard CDs, and other than looking alike, they are not comparable to CDs and cannot be played on standard CD players. But all (I think) CDs can be played on SACD players (backward compatibility) , but of course this does not improve the CDs music quality, ie it's still 16 bit words sampled at 44.1 KHZ (Redbook CD standards).

Actually, HDCD and SACD are totally different technologies and cannot be directly compared (except for the music). SACD is more appropriately compared with the also new DVD-Audio discs, and from what I've read they are sonically comparable, but already each has it's adherents. A "format war" is expected between the SACD and DVD-A technologies.

But, in my opinion, CDs are going to be the dominent music format for years to come as it is well accepted by the public in general and has improved sonically in the last five or so years. Good Luck. Craig

Pacific Microsonics HDCD is a 20 bit CD format also compatible playing on 16 bit redbook players (but without decoding the extra resolution). It's a wonderful system because these decoders make even 16 bit CD's sound better when played through them. The HDCD's don't cost $25 each either. PC audio has even recently adopted the standard. Comparing the same recording on redbook vs. HDCD is just no comparison; the added resolution, air & dynamics make this choice a no brainer.

doens't the SACD goes from 0HZ to 44KHZ ??
i think i read that somewhere..
but doesn't our ears only get from 23-24HZ+ to 22KHZ ?

What do you think about SACD multichannel ?
does it really helps with the reproduction of the music ?
What is presently the BEST for music quality ?

talking digital,vynil ...

I also will not ever buy SACD and anytging that plays it -- costly and not everything you can get in this format. HDCD is almost like a regular red-book CD: could be worse and could be better depending on the recording quality. There is an actual possibility to comapre HDCD with regular one by buying Dire Straits "Love Over Gold" album that had been remastered for HDCD format. HDCD certainly sonds much better. Also there are few more albums from Dire Strats had been remastered to HDCD. My collection of Dire Straits (average price is $3 for each record) is analogue and no HDCD can beat it! Analogue vinyls and turntable are my SACDs and SACD-player!