 Compared to a reflective surface, which will cause most of the energy to be reflected off at an angle equal to the angle of incidence, a diffusor will cause the sound energy to be radiated in many directions, hence leading to a more diffusive acoustic space.It is also important that a diffusor spreads reflections in time as well as spatially.Diffusors can aid sound diffusion, but this is not why they are used in many cases; they are more often used to remove coloration and echoes.