Stereo & Electronics - Sail panel and sound deadening

When I was interested in swapping out my sail panel speakers I noticed that there is basically a cave behind those speakers. I think I could probably stuff a pillow back there. Has anyone sound deadened this area and if so, how?

When I was interested in swapping out my sail panel speakers I noticed that there is basically a cave behind those speakers. I think I could probably stuff a pillow back there. Has anyone sound deadened this area and if so, how?


You know i was wandering the same thing??

I dynomatted everything I could touch w/my arm (btw, do a decent job taping or using split rubber hose on the edges...) and dynomatted the outside also... Never thought about a pillow, but thought about that expanding foam stuff...

I used sound matting in there when I did my car. I could not tell you if it helped or not because I did the whole car at once.

I sound deadened as well as stuffed a bunch of poly fill back there.