LPCM 7.1 will not play in 5.1

[Modify_inc]

I just ripped a BD of The Descent, and the audio is LPCM 7.1. My system only supports 5.1, so I figured it would play it at 5.1. When I play the audio, it says it's in 2 channels (stereo). So I ran it through eac3togui and converted it to ac3, and it now plays in 5.1. Why would it not play in 5.1 using the raw LPCM?

[guns1inger]

What are you playing it back with ?
How is everything connected ?

It is either because you are using an optical cable, and therefore TrueHD audio is not passed through, or because your amp simply cannot work out what to do with 7.1 LPCM. 5.1 AC3 is just DVD audio, which is a no brainer for the amp, and isn't protected by newer methods. BluRay players and the PS3 will only send HD audio over the HDMI cable, not a standard optical audio cable.

[Modify_inc]

What are you playing it back with ?
How is everything connected ?

It is either because you are using an optical cable, and therefore TrueHD audio is not passed through, or because your amp simply cannot work out what to do with 7.1 LPCM. 5.1 AC3 is just DVD audio, which is a no brainer for the amp, and isn't protected by newer methods. BluRay players and the PS3 will only send HD audio over the HDMI cable, not a standard optical audio cable.

I'm using a Sony receiver playig through WMP and VMC, connected HDMI to HDMI. I've done most of my BD collection with no problems it's only this movie. I hope I got the correct stream, there are like 3 or 4 to choose from with this movie. The first LPCM audio track I tried, threw me off, it played the background music and sound effects, but had no voices when people talked, I thought that was odd. I could hear the rapids and everything during the beginning rafting trip, and I was like why can't I hear them talking and screaming. So I tried another playlist, and the LPCM track from there played fine, it just showed it was playing in stereo for some reason. I ran it through eac3 to ac3 and played it again, and it played in 5.1.

Hope that helps