Hey all I am hoping someone here can help me. I have a Yamaha 5.1 surround sound receiver (Model HTR-5730... and older receiver that has gotten pretty good reviews). I have my Xbox and my Dish receiver (HD Tivo) hooked up via optical audio and my hdmi dvd player hooked up via coaxil. When I am watching a HD program my receiver has nothing but bass during commercials unless I switch it to 5 channel stereo instead of DTS/DD. This also is annoying when watching any type of musical dvd (Rent and Nightmare Before Christmas had the most problems.) Nightmare Before Christmas you could not hear the line "This is Halloween" in the opening song as I am guessing they are supposed to come out of the rear channel and all that could be heard is the music but when i change to 5.1 it works great. Is it the encoding of the source audio, the surround receiver, or the speakers? I have tried seeking the problem online but with no luck. I've even reset the speaker settings on the receiver to default in case I had too much center or not not enough rear sound but still with no luck. If anyone has any ideas please let me know.