I have a Paradigm PS1200 which I bought a couple of months ago. Been having lots of fun with movies at loud volumes, where it literally shakes the house. It's a hoot! However, recently I told this to my friend and he mentioned that I should make sure I'm not overdriving the sub. I'm really an audio noob so this sort of thing isn't intuitive for me. I've been running it hard because I haven't noticed any major distortions (like the bass sounding totally loose, or rattling really loud). Making matters more complicated, I do almost 100% movies which means alot of the time it's hard to tell whether my sub is distorting or it's the signal. From listening position, I do hear rattles on occassion when playing at my normal, pretty loud volumes, but alot of that is from the blinds and doors and other furniture of the room so I've been ignoring them. I decided to put on a test. I would play a bassy sequence over and over and put my ear up to the sub turning the volume up and down. However, I noticed that even at moderate volumes, I hear a slight rattle coming from the sub. My buddy told me that ANY rattle from the sub is bad - something about the cone hitting something. I normally play the sub louder than the volumes where I first start hearing a rattle, too. So does this mean I've been beating the sub too hard and it's now damaged? How do you tell whether you're pushing the sub too hard? What is this "clack" I've heard about? Is my sub OK? I've also read that the sub I have tends to be boomy, so is that why it tends to rattle slightly?