What kind of
system you are using would really help. If you are viewing shows / movies that are more then stereo, you may be having an issue with loosing the center
channel (if it's not plugged in or something) and just hearing the right and left, which in movies and such are containing less and less of the vocals as more people have surround systems. At my college we have taken to doing a temporary setup of a center
channel when we show films in our
hall that otherwise only has stereo sound. (we are running the audio off of the film (35mm) into a real Dolby Digital 5.1
system but before our temporary setups, only L and R speakers (and a
bass unit) are actually plugged in)
I really dont think most TV is being broadcast in 5.1 these days, although maybe if you have a higher end cable or something like that it is....