Running that sub "too hot" or even "full out" won't create the rattle you describe. I vouch from experience.
Something else is wrong.

One time, I replaced the front grill upside down. That put two of the pegs directly in contact with the woofer, and the rattle was terrible. I was horrified at the sight when I took the grill off. Thank goodness there was no damage to the cone or surround.

Shawn

Epic 80/600 + M3's + M3 Algonquins + M2 Computer + EP125
I think I'm developing an addiction.