Dolby Pro Logic IIx not being applied? Newbie here, please help

[JimmymatthewB]

Hi all, first of all I apologize if this thread is in the wrong spot. This is actually the first time I've ever posted anything on a forum.
So I recently bought a surround sound setup. I have the Yamaha RX-a3000 receiver and Mirage Nanosat 7.1 setup w/mirage dedicated cc.
My first question regards dolby pro logic iix, which my receiver is capable of applying. It only works for certain things however, and they seem to few for comfort. My PS3 or XBOX 360 do not produce sound from my 6th and 7th channels while on the main menu's. The matrixing is applied when I play games, but only works for, I'd say, 50% of them. It also does not work for ps2 or regular xbox games. It works for most dvds and blu-rays. I was under the impression that everything could be matrixed to 7 channels with plIIx applied. Everything is hooked up correctly, and the appropriate sound settings are being output from the consoles themselves. I am just new at this and not sure what is going on and it is a bit unnerving.
I would like to add that I contacted Yamaha tech support and they seem to think this is totally normal, but seemed like the guy didn't know much more about decoding or audio in general than myself, which doesn't make me feel much better. Thank you so much in advance!!

 

[jostenmeat]

You likely have to go into the receiver menu, where you can set default listening modes for every assignment/source, AND for every codec for each of those sources.

Example, for HDMI1-PS3 (if your receiver is like mine) you can set PLiiX as the default for DD, DTS, DTSMA, TrueHD, PCM, and so forth. Then repeat for every other source.

 

[darien87]

I believe that PLIIx only works with a 5.1 signal.

This makes sense when you think about it. It's not matrixing the menus of games and DVD's because those are most likely just 2ch audio. The fact that it works with DVD's and BD's seems to bear this out.

The only Codec that will matrix 5.1 out of 2 ch that I know of is DTS Neo:6

 

[MDS]

PLIIx works with any analog or digital 2 channel signal as well as DD/DTS 5.1 and 6.1.

In order to matrix the surround back channels it has to take cues from the audio, such as out-of-phase audio, from the front channels. There just may not be enough content to extract meaningful information for the rear surrounds. It's really the same reason that even movie soundtracks don't always have a lot of content in the surrounds or rear surrounds.