HDCD Decoding ?


Recently, I have noticed that the specifications for CD players sometimes mention that they are compatible with HDCD CDs. I thought that HDCD died about ten years ago. But HDCD CDs have always been playable on any CD players; albeit not all CD players would decode the HDCD formatting because that required a special digital filter from Pacific Microsonics.

Several years ago, when HDCD first appeared, Pacific Microsonics required that anyone licensed to use their HDCD filter had to install automatic attenuation in their players for ALL non-HDCD discs. This was not necessarily a good thing.

When a 21st century CD player will read HDCD discs, it may or may not perform the automatic change in volume as a result. The net impact in older HDCD players was that all normal (non-HDCD) discs were attenuated. I own a few hundred CDs and only about 6 of them are HDCD. I expect that now in the year 2013, this is no longer a problem regarding the Pacific Microsonics HDCD filter. My guess is that current players are not using a Pacific Microsonics filter.

Perhaps "compatible with" is simply a reminder that the CD player will play the older HDCDs as regular CDs?

What says the group mind?
poetcatullus
There is some good information on HDCD on Goodwin's website, including links to original papers on the subject.

Information on HDCD

There is a also a very comprehensive list of HDCD CDs there.

HDCD CDs

According to the FAQ on that site the reason some HDCDs do not have the HDCD label on the case was that the artwork was completely prior to the mastering process.

Good news!

I emailed Oppo directly and sent them the link to this thread. Here is their response (which was virtually instantaneous):

"There is no attenuation for Red Book CD. When playing a HDCD the player will decode the HDCD from 16-bit to 20-bit then expand to 24-bit word length. CD and HDCD is still processed at 0dB reference, with extended HDCD done at -6dB to allow for the expanded dynamic range."

In a follow-up email they verified that the concern that started this thread is obsolete and that current HDCD capable players no longer attenuate standard CDs as they had done back when it all started almost 20 years ago.

I am grateful that we can now all move on and enjoy the music!
I got into cd's a little late but eventually discovered HDCD
more or less by accident...I noticed Joni Mitchell,Blue I
think,sounded pretty good by comparison to most other cd's in my small collection,and noticed also the HDCD logo on the back.This led me to look for that logo when I bought cd's,
as someone else mentioned ..Grateful Dead/Dicks Picks,other
Joni Mitchel,etc..So I replaced my pretty much brand new Yamaha cdp with a Harman kardon 8380/HDCD.Not hi-end but an
upgrade to my ears.I have an older Leonard Cohen cd,Songs of
Leonard Cohen,not HDCD, that was pretty rough on the Yamaha but really smoothed out on the HK so its positive affect on non-HDCD
cd's was a little gravy.Anyway I eventually hooked a Micromega Mydac into the system and didn't
really think of the HDCD one way or the other until somewhere along the
line I wondered if it was being passed along.Did alot of digging
and the consensus,though not unanimous,was that unless the external dac was HDCD,then the HDCD from the Harman -Kardon was
negated.At first I was bummed but the Mydac was a clear
improvement to my ears so I got over it.But no, the story is not over..I saw a Heed Obelisk DT transport here on Agon which reads HDCD,so it
caught my eye,but I am now confused again about HDCD and how and
where it gets de-coded.I just emailed Heed Audio to see if they could
clear this up for me.I came across this thread while looking up
HDCD and because it was the most recent posting I figured I'd wake
up ala RIP Van Winkle and see if anyone is still interested.
And apologies for the long wind of this but I tried to keep it as
short as possible.The long version is available upon request.