Sound diffusion is the efficacy by which sound energy is spread evenly in a given space. A perfectly diffusive sound space is one that has certain key acoustic properties which are the same anywhere in the space. A non-diffuse sound space would have considerably different reverberation time as the listener moved around the room. Acoustic diffuser is not only for sound diffusion, but also remove coloration and echoes. It is widely used in music room, recording room, church, multi-functional room, theatre, concert hall, etc.