home theater advice

You need to explain what you mean by "sqeaky voices". Can you hear the movie sound but it's high pitched with no bass? or are you getting sounds not in the movie? If the first you may not have the surround mode set up WIDE which lets all the bass through to the front speakers. What is your surroung component?

Is your problem occurring with DVD? If so, a DVD player capable and set for output of a DTS bitstream played thru a reciever (or pre-amp) that does NOT have DTS decoder will cause a high pitched, high level squeal.