Sonic Barrier MX-4 Max Aluminum Foil Butyl Foam Rubber Sound Damping Sheets 31.5" x 18.12" 4 pcs.

Great deadener and decoupler. Don't expect it to soundproof your car. It reduces vibrations and some external noise due to the weight, but it doesn't block the sound. As for midbass increases, it seems to have fixed most of the lacking midbass I've had.

I purchase this item from a source. Amazon and PE price are the same. Regarding the product and I have have used a few, this is a great product. It cuts easily and sticks very well. I let my neighbors hear the different in door panels. It is a noticeable different. The next morning I tired to remove a small section, and it was very difficult.Save yourself time, this is a good product.