Are the new DTS HD and Dolby HD backwards compatible?

[admin_exported]

How do the new HD formats sit with all the old Dolby/DTS world?

Let's say I have a BlueRay player and an old surround amp. For a Blueray disk with ONLY HD sound on it what will come out of the amp?

Apologies if this has been covered before.

 

[Andrew Everard]

Not sure there are discs with only HD sound on them, though I'm happy to be corrected. That's so for exactly this kind of back-compatibility reasons, enabling you to use the player and the discs with older amps.

If there were/are such discs, you won't get any sound at all, as conventional electrical and optical digital links can't carry the HD datastream, and of course your old amp couldn't decode it even if they could.

Anyway, if you had an older amp with 5.1-channel inputs, you could run analogue connections from the player to the amp and enjoy the HD sound, decoded in the player, that way. At last a use for those multichannel inputs!