Welcome to the forum mrondeau,

I am glad you and your family are enjoying the M80's. I agree with what the others have said and that through Axioms development, design and testing of the speakers has determined the adequate amount dampening material for inside the cabinet.

I am not familiar with tweaking but if you have your mind set on replacing the stock padding I have seen some recommendations for using high-density rockwool in DIY projects.

Cheers!

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne