for 5.1 system Dolby Digital or DD+Dolby PLIIx-C

I have a 5.1 system and for watching lets say TV, DVD or Blu Ray Disc in (5.1 system) which you guys use as a a surround mode:

Dolby Digital or DD+Dolby PLII-C


I know it could be preference but just want to know what the pros prefer for HDTV and DVD's given a 5.1 system. thanks for your feedback.

These two options assume that you have a Dolby Digital signal, and it depends on whether the Dolby Digital signal is 2.0 or 5.1. In a 5.1 system and with a 5.1 source, then DD+PLII-C isn't going to be an option (you already have all six channels in the original source, so adding mode via Pro Logic II processing is impossible). For Dolby 2.0 sources, I use DD+PLII.

so gonk, if i'm wathing HDTV, lets say HBO's Soprannos, and i'm able to engage DD+PLII-C, then its not a DD 5.1 source? Is that right?

That would be correct. Pro Logic II extends two-channel sources to 5.1 and as such is not applicable when working with 5.1 sources. (Pro Logic IIx can be used with 2.0 or 5.1 to create 7.1, but only if you have enough speakers.)

Here's a handy trick that the 970 carried over from the 950 (which I used to own): when the processor first acquires a digital signal, the front panel display lists the specific format of the signal. Common examples are "PCM 48k" (PCM stereo, as found on CD's and some TV channels), "DolbyD 2/0.0" (Dolby Digital 2.0), "DolbyD 3/2.1" (Dolby Digital 5.1, with the "3/2" referring to three front channels - left, right , center - and two surrounds), or "DTS 3/2.1" (DTS 5.1).

thank you gonk for clarifing.