this isnt rocket science. try giving it its RMS rated power. just a suggestion.
but honestly, i dont know where you get your info from but never in my life have i seen or heard (except on a forum ofcourse) a sub failign thermally from under powering.
this is classic.
Quit trying to act like you are better than everyone, you're not.
The reason it could fail thermally from underpowering is because it will not have enough movement for the cooling to take place.
you just said same thing the other guy said. why? i read it just fine the first time around. you are talking about a myth, a made up concept of thermal damage while under powering.
PS. I am better than everyone, clearly.