My setup consists of a DVD 5.1 home theatre system which only allows for optical audio input (only hdmi output for playing dvd's). I have a fat ps3 and my virgin tivo box connected to the home theatre with optical cables. When I'm watching a HD tv channel for example, I get 5.1 surround sound, no problems, all is well. Similarly if I play a dvd or blu-ray in my ps3, then I have 5.1 surround sound.
My problem is this: my latest purchase, The Lord of the Rings extended edition on blu-ray has audio in 6.1 HD. When I tried to play the films, I wasn't getting any sound during the movie (the intros were fine, as were the commentary tracks). With some research and experimenting I found that I needed to change my ps3 settings from 'bitstream' to 'pcm direct'. I imagine this is because my home theatre system doesn't support HD audio, so by changing to pcm direct the ps3 will decode the signal and send it in a format that the home theatre can understand. I thought I had solved the problem... however I've since read online that optical cables can only transfer pcm sound in 2.0 stero, not surround sound So even though it is coming out of all four speakers, that is basically just the home theatre splitting the stereo signal to give faux-surround, as it were.
So, from what I can gather so far (I'm no expert by any means), if I play a dvd or blu-ray that has 5.1 audio, then I get surround sound. If my blu-ray disc has better (HD) audio, then I in fact the end result is that I can only receive 2.0 stereo sound... in other words the better the audio on the disc, the worse the audio I actually get with my setup
The only possible solution (I think) I know so far:
Buy a new home theatre system that allows a HDMI input and/or supports HD audio. This should then work on either bitstream (if the home theatre supports hd audio) or pcm direct (the hdmi cable could transfer surround sound).
What I'd like to know is if there is any way of getting my blu-ray discs recorded in 6.1 HD audio to give me surround sound with my current setup? I previously assumed that when the ps3 played the blu-ray and realised that I didn't have a 6.1 HD audio setup, that it would default to some kind of 5.1 standard surround sound, which would be fine!