Cascade VB-2HD Acoustic Damping Sheet 13.9 sq. ft.

Very good product, Used this to dampen the vibration noise in the roof of my tractor cab and it worked great.Amazing the difference, looks like it came from the factory.

After a lot of study, I ordered this to line the inside of my DIY woofer box. (I'll also use some fiberglass.) The most up-to-date damping for cars are "constrained layers" backed with aluminum. BUT the layers are not really constrained if they are glued-peel-and-stick to a medium density composite cabinet. Then I realized that mass-filled vinyl is in effect a bunch of very-well constrained layers, since each particle is surrounded by elastomer, and so can turn the vibration energy into heat in effectively the same way a constrained layer does by resisting the movement and turning it by friction into heat -- and maybe even more efficiently, since the surface area of the particles could exceed that of a flat constrained layer. We'll see. But I thought others might be interested in the reason for my provisional 5 star rating. I'd be grateful if some physicist came along and commented on my reasoning.