Dynamat Xtreme Door kit

Dynamat Xtreme door kit
The package includes 4 pieces of 305mm x 914mm pieces.

https://www.youtube.com/watch?v=3BxMQW6b6yM&feature=youtu

Even the best speakers cause distortion of the speaker mounting surface.
Home speakers are normally in well-made, heavy-duty enclosures to
no distortion occurs. This is a solution that is impossible or at least really
impractical in your car. Dynamat is the solution to this problem. By installing
The Dynamat damping mat on the surfaces surrounding the speaker eliminates distortion.
The Dynamat damping mat makes the car's weak thin damper sturdy and
resonant. Dynamat improves the performance and eliminates your midbass
resonances. The car stereo sounds as good as possible.