Hello all, As the heading states, I recently purchased a Sony SAW40 subwoofer. I've read you can fill the sub to make the sound "punchier" and owuld be interested in taking this project on. Problem is I have no idea what I'm doing and need some guidance. What material do I use? How much , quantities? What kind of improvement can expect? Anyone have experience with this sub and modification? All help would be gratefully appreciated.