Sound dampening / damping materials for loud speakers

Hi

Does anyone have experience with locally sourced sound dampening materials for use within loudspeakers?

I would like to hear your experiences with the different types of material as well as how they can be fixed, e.g., type of glue, staples, etc.

So far I have found sources for both polyethylene closed cell and polyurethane open cell foam.


Thanks in advance,

Smitty