How exactly did you blow your subs?
Did the cone detached warp in any way? surround torn? (this is mechanical issue)
or did you smell something burning and now the voice coil scratches when pushed down? (this is thermal)

Let me clear up some misinfo in this thread,
under powering a sub does NOT kill your sub, leaving it to play fullrange does NOT kill your sub. Clean power does not mean you can't kill your sub with it.

I'm taking a wild guess, your sub was in a ported enclosure?
Under the tuning of the ported enclosure, it doesn't take much to overexcurt the sub. You can blow your subs if you aren't careful with the gains and have no sub sonic filter.