Dynamat on ///M Coupe Subwoofer

The bass is noticeably better. I purchased a pack of 5 square foot pieces which was enough to do the whole job. Eastwood’s 1-800-345-1178 item number 52105 $19.99. Each square foot weighs aproximately 10 ounces. About 3 pounds added weight substracting the scrap.

– From the Dynamat Literature –

Dynamat Original is a Styrene-Butyadine-Rubber based and Pressure Sensitive Adhesive Backed, Heat Bondable, Sheet Metal Vibration Damper. This product is made to conform and fuse to automotive body surfaces such as floor pans and doors. Product shall be die cut to shape and placed onto the body surface after sheet metal cleaning operation and prior to the paint system (typically at the sealer application operation) or on painted panels. Adhesive side is smooth, giving complete contact with the underlying surface without any air pockets of channels. Both material and adhesive can withstand temperature ranges between -30C to +177C(-22F to +350F) and are highly resistant to aging.

Acoustic Properties

The acoustic loss factor ‘n’ is used as a measure of ability to damp structure-borne sound. It states how much vibrational energy (in steel sheets, for instance) is converted into heat rather than sound. For constructions containing several layers, the combined loss factor ‘n comb’ is used. The theoretical maximum loss factor is about 1. An undamped steel panel 1 mm thick has a loss factor of roughly 0.001 at 200 Hz. Damped with Dynamat Original the loss factor would be about 0.16 at +0C(32F). Multiple layers of Dynamat Original can be used to improve sound daming still futher.


Dynamat Original is used as treatment for metal panels, partitions, ducts, doors, bins, panels, etc. in railroad cars, buses, automobiles, and ships. It is also used for ventilation ducts, relay cabinets, steel furniture, sink units, office machine, computer equipment, machine tools, and for many other purposes.


Dynamat Original should be cut to the desired size and shape before the backing paper is removed. It may be cut with scissors, knife, or die. Remove dust, grease, moisture, and other foreign matter from the application surface. Peel off the backing paper. The simplest application technique is to bend the pad slightly and attach it along its shortest edge. The pad is then pressed firmly into place, preferably with a roller for larger pieces. This reduces the risk of leaving air pockets, which reduce the sound damping capacity. The temperature of the pad and application surface should not be below room temperature during fitting. Heating the material before applying is strongly recommend, and increases flexibility, strechability, and adhesion.