All the above being true and correct, I'd add that it could not hurt to drop an email to Axiom and ask what would happen if you add new or better dampening material. I don't know if any of the forum's member are accomplished speaker designers, but Axiom certainly has a few could give you some support.

Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire