John - I turned off the subwoofer, set the speakers to large and popped in a cd with some good bass. The discovery wasn't pretty because the two bottom woofers are not working..:( I bought these used and unfortunately didn't notice it when I listened to them. These speakers were purchased from the original owner last July. I am going to email him and see if will help out some, but he probably won't....Guess that solves the mystery..