Usually I don't have this problem but when I'm home alone I like to crank my music up a little. In songs with hard hitting bass lines, the subwoofer rattles from the back metal plate (where all the inputs are). If I apply a little bit of pressure with my fingers, the rattling goes away but comes back when I take my hand off. I tried tightening the screws in the back because I thought something might be loose but that didn't help. Is there an easy fix for this?