Where's the HDCD?

Hi Gary,

HDCD is much like JVC's XRCD and Sony's SMB in that 20 bits of data are encoded into a 16 bit space. The major difference between HDCD and the others is that to hear the full potential of the disk, you need to have their chip. I haven't investigated this thoroughly enough to say more on this, but I suspect that Keith Johnson could speak volumes on why this is so.

In a sense, then, both krabappple and you are correct about the format.

If I may draw a loose analogy, it's like a game on CD-ROM: it will play in a drive/computer of any speed, but will perform better in a faster one. And, of course, depending in your graphics card, you can see it in action on anything from a 4 bit to 32 bit color monitor.

Although HDCD has been on the market for quite a while, I didn't take much of an interest in it until the Absolute Sound started writing about the differences in software performance about five years ago. Interesting, though, that very few of HP's reference list sports only a few of them (and they are impossible to find). No, it's not as convincing as SACD.

 

I'm with you on this one krabapple. If a recording is done digitally at 20 or 24 bits it must be dithered down to 16 bits for redbook standard. I believe HDCD attempts to use a "DBX" type approach to try and maintain a semblance of more than 16 bits. My experience says that they are no more successful than other bitmapping approaches.

The DOWNSIDE is that I do not feel that HDCD discs reveal the maximum quality on non-HDCD players. IF they did then why do we need to have HDCD players at all?

Having had the Adcom 600 DAC (non-HDCD) and the replacement Adcom 700 DAC (HDCD) I have come to the following conclusions.

*THE HDCD chip is better than the CRYSTAL (?) chip in the 600 DAC.
*HDCD playback can sound very good on HDCD players.
*HDCD playback on non-HDCD players can sound good but will not sound as good as
on a comparable HDCD player. There is a compromise in sound. This was very clear to me when listening to Emmylou Harris Wrecking Ball (HDCD) on both Adcom DAC's.
*There are newer chips available that outperform the HDCD chips.

Bottom line (IMO) - Get the best sounding CD player you can without regard to whether it has HDCD or not.

 

Hmmm...

If HDCD encoded cd's are still only 16 bit when they are being decoded then why do most of the CD player manufacturer's put 20 bit DAC's into their units? I specifically avoided the Harman Kardon FL 8380 because it only has 18 bit Burr Brown PCM1732 DAC's in favor of an older model (FL 8550) that has 20 bit Burr Brown PCM1702 DAC's.

 

Oh, yes. The individual Doors CD's are HDCD encoded, no question.
Wow, quite a monster I created. I should probably say that there are certainly a lot of HDCD-encoded discs that sound incredible to me: Doors, the Dire Straits "Very Best Of", and the Van Halen remasters among them
(I was quite impressed with the sound AND the volume ).
My Denon HDCD player does make a difference between HDCD discs and non (although often subtle). What's really weird are the soundtracks and compilations that have some songs that register as HDCD, but the majority don't. One soundtrcack ("Sweet November") has a song that makes the HDCD blink on and off constantly throughout the song (in a random pattern). I wonder how that happens?
But there's a lot of HDCD CD's that are still harsh sounding to me, and a lot that don't seem to derive any benefit at all.

I guess I'm pretty jaded these days about sound and I'm not impressed with a most CD's sound- although there's still some that sound magnificent (assuring me that my stereo isn't a total piece of crap). This week it's the new Bryan Ferry that sounds sublime (not HDCD encoded .

nashreed

 

i fyou read that quote again, they aren't saying that the playback really is at 20 bits -- they are saying that they have managed to 'encode' the extra 4 bits of information into the *existing * CD format -- which is 16 bit.