In addition to the problem I'm having with my subwoofer right now there is one other thing that has been irritating me about my system. If I turn the input level on my amp up very much then I can hear a faint high pitch whistling sound coming from my system when I'm driving. The harder I accelerate the louder the sound becomes. If I turn the input down a bit the whistling sound goes away but then I can't really get the volume out of the system that I want. I'm really new to audio equipment so the only thing I've checked is to make sure all the connections that I have access to (my amp) are secure.