DVD-Audio discs can have 2 "zones": a DVD-Audio Zone and a DVD-Video zone.
The DVD-Audio zone contains, of course, the DVD-Audio (2 channel, 6 channel, MLP, whatever). It can also contain some visual content such as stills of the band, lyrics, etc.
The DVD-Audio zone is unrecognized by DVD-Video only players. However, the DVD-Video Zone looks exactly like a DVD-Video disc. The DVD-Video zone can contain anything and everything that a regualr movie disc does including:
-Dolby Digital Soundtrack (in any flavour)
-Stereo PCM soundtrack
Recording companies are very much being encouraged to include on their DVD-audio releases a Video zone containing a 'copy' of the music so that people without DVD-audio players can enjoy the multi channel mix (albeit, without the added quality of MLP).
Future movie DVDs will NOT have DVD audio soundtracks.
As to your question about the quality of DTS in the Video zone of DVD-Audio discs versus
DTS music CDs, that is entirely up to the people that make the disc. It is up to them whether there is a DTS soundtrack there to begin with, or whether there is a DVD-Video zone at all (though if they do
provide a DVD-Video zone, they must
provide either a Dolby Digital or PCM sountrack in it)
Secrets of Home Theater and High Fidelity http://www.hometheaterhifi.com
[This message has been edited by Brian Florian (edited 02-02-2001).]