u/rozlick

As the title says, I am looking for the best speaker insulation material. Should I use some sound foam as picture 2 shows or some polyester damping wool?

On picture 2 is a centimeter thick semi-soft foam panel from a local foam company and on pic 1 is just generic speaker fill.

As the title says my laguna made a hissing noise, i think it might be the ac, as it was the first time i ran it for so long.. but it doesn't sound healthy so I just wanted to check Its a 2.0dci 136hp or 96kw, with a timing chain