High Definition CD or HDCD - What is it exactly?


I have an Audio Aero Capitole MKII and always thought it had the ability to read HDCD's. I thought this until recently playing an HDCD on a friend's CEC CD player which has a small light that appears that tells you that it is reading the disc as an HDCD. The improvement and realism in the sound was awesome. The realism in sound reminded me of SACD in many ways, although I don't have much listening experience with either HDCD or SACD.

What exactly is HDCD and why can't the Aero Aero (at this price point) play/read these types of CD's?

One more thing...I burned a copy of the HDCD, but the CEC player did not recognize the copy as an HDCD.

Your comments are appreciated. Thanks,
128x128gerryn

Showing 1 response by tobias

HDCD is a brilliant scheme which encodes extra audio information in the dithering signal present on all Redbook CDs.

The dither is put there to increase the number of bits in the lowest-level signals and thus improve resolution. On normal CDs it contains no signal information. The HDCD dither looks the same as the regular kind to a normal CD player. However to one equipped with a decoding chip, it delivers its information. This information can improve dynamic range, HF resolution and more.

The HDCD decoder chip must include very precise filters. These filters are sometimes better than those found on ordinary Redbook players. Consequently a CD player equipped with an HDCD chip may do a better job than a standard player on normal, non-HDCD-encoded CDs.

The only downside to playing a non-HDCD disc on a player with an HDCD chip is a slightly reduced volume level. Compensate by turning the volume up about 6 dB.

I own no stock in Microsoft, now the owner of HDCD. I just think the system, created by Pflash Pflaumer and Keith O. Johnson, is very elegant. It really can improve CD sound, too. Just too bad it's not in wider use for Redbook material. However if you have an HDCD-equipped player, you may get a surprise sometimes. With the occasional disc, the HDCD light comes on to show the extra info is there, even when there is no mention of HDCD on the disc wrapper.