Evans 22" EMAD Coated Bass Batter Evans™ EMAD™ series features a single ply of 10mil film providing an ideal balance of punch, power and low-end. The unparalleled industry standard Externally Mounted Adjustable Damping (EMAD) system allows the player to adjust attack and focus. The coated surface provides more low register and attack. About the Evans Drumhead Finish The finish of the drumhead is most often thought of purely from an aesthetic point of view, though there are often sonic characteristics that go hand-in-hand with specific finishes. Coated or Frosted finishes are said to add warmth to the tone of the heads, whereas uncoated heads tend to have more definition or attack. Coated batter heads also offer a texture that is ideal for brushes. Though most people use clear reso-side (bottom side) heads, the use of a head with some form of coating will further reduce overtones and result in a warmer sound.