im playing some xbox with my new setup consisting of a pioneer receiver with dolby digital 5.1. i have 2 front 2 rear and a sub. but when i play dolby digital on it i only hear sound affect the voices are barely audible sometimes i cant hear voices at all the only acception is is that when i put it on dolby digital p11 MUSIC i can hear both sound affects and voices i can also hear sound affects and voices on the stereo mode. how can i fix this?