I thought my sub was blown and when I looked at it closely, I saw that the foam was torn all the way around it. Just for the heck of it, I took the plastic rig off the sub and put a small bead of sylicone rubber on the tear. I waited for the sylicone to set up a little bit then put the rig back on. To my surprise, it's been fine since May 04 and I can even turn it all the way up.