The quality of surround sound can have a huge impact on the frequency response of speakers. Through the correct choice of materials and design, EP can ensure that the vibration behavior and linear motion of the cone will not be threatened. Therefore, a variable-thickness housing can be manufactured with very high precision. By balancing the geometry and materials according to the customer's personal needs, specific damping characteristics for surround sound can be achieved. EP produces high-quality grades of NBR, SBR, IIR, foam rubber and special quality rubber skins through vulcanization. The common coastline bundle is 55~75 coastline A.