I have a Denon AVR-4306

We have a high end cable box HD-DVR with optical out (Scientific Atlanta) and Cablevision in CT and commonly watch HDTV sources.

Clearly, when watching a DTS encoded movie, I want to use DTS mode -- however when watching TV I am a little lost, as every channel and show are different.

From what I can seem to gather, most TV shows are not in DTS, so it would never be a DTS mode...

But as for Dolby, there is:

Dolby PL EX
Dolby PL
Dolby PL Matrix
Dolby PL Cinema

as well as other modes in the Denon such as:

"Widescreen"
"7 Channel"

Etc. What am I suppose to be using? I usually leave it on Dolby PL Cinema but from reading the book it sounds like it is suggesting "Widescreen" -- do I have to change it depending on if the show is Dolby encoded? How would I know?

While we are at it -- what should I use for non DTS movies (Assuming Dolby PL Cinema?)

I'm so confused... any help would be appreciated.

-John

One place to start is here, http://www.dolby.com/consumer/technology/tech_overview.html where you can get an overview each Dolby flavor.

HDTV audio is usually DD5.1 (no rear surround). Use PrologicIIx Movie to create to derive two rear surround channels.

Some HDTV and digital SDTV is DD stereo (at best). Use ProLogicIIx or one of the other processing options to create full surround programing.

Some DVDs are in Dolby D EX (6.1 mono rear surround).

Usually you can set up the reciever so that it has defaults for each type of signal. For example, DD5.1 could have PrologicIIx as the default of just DD5.1 (nothing on the back surrounds).

You get to experiment. In my case I've pretty much settled on PrologicIIx for DVDs, HDTV and SDTV, but once in a while drop back something else, especially if the original has a mono or a non-Dobly stereo sound track.

Do you suggest deriving the back two channels, or is the audio better off being left in 5.1?

In 5.1 should I be using my sides or rears?

Do you suggest deriving the back two channels, or is the audio better off being left in 5.1?I would derive the surround-back channels. It'll give you wrap-around envelopment and stable rear-vs-side directionality in the surround field. You'll never get that from only 2 surround speakers.

Sanjay