“What needs replacing Have 15 year old home surround sound setup and new Vizio HD TV. Hooked up by Geek Squad, but sound is not crisp and it's hard to hear. I've had my ears checked, so it's not that. What is the first thing you would suspect? The receiver, speakers, sub-woofer (replaced a few yrs ago). Where should I start to correct this problem and have the clear, crisp sound that I hear at other homes. Thanks, Onkyo Audio Bisual Receiver, TX-DS575, Vizio, Model #E3901-Al, Polk powered subwoofer, PSW111, MB Quart Surround Speakers. HELP!”