Sound volume problem

Hi all, has anyone come up to the same problem as I do ? After I stalled the AC3 Filter, all the movies that required codec to play has a very very low volume,even I turned my speaker volume and the pc speaker to a maximum, the background sound is good, but only the voice of the characters in the movies can’t be hear..any help please ?

i’ve had the same exact problem too. i don’t know what’s up tho. if any one knows or finds out please post.