[bluray]

I've only been able to get 5.1 audio with movies, but I verified that I can send signals to all 8 speakers independently using W7's built in speaker config screen, as well as verifying that my receiver sees all 8 speakers accordingly. However, the real problem could lie with the video encode I was using (even though MediaInfo shows it as having an 8 channel DTS audio stream). I thought I had 7.1 DTS-HDMA audio in it (DTS-HDMA lights came on on the receiver), but XBMC showed it as only outputting 5.1. So is there something I'm missing with this tutorial to get this working properly?

Did you select 7.1 in Windows 7 control panel and XBMC audio output?

Yes I did.

Are you saying your AVR showed 7.1 and XBMC showed 5.1?