what is the right audio setting with dv-47ai?

When I play dvd, the picture quality is very good, but audio portion is less than par. It sounded like that is a blanket hovering around the speakers. I tried playing around with the settings, no noticeable improvement. Your advices and feedbacks are greatly appreciated. Here is my system:
Rotel 1095
Rotel 1066
Pioneer Elite dvd dv-47ai
mitsubishi 55 hdtv
B&W Nat. 805
Lat International component cable
MIT Terminator 3 interconnect
Tara Labs Toslnk digital cable
RGPC 400

Thanks