Diffusion
Definition
The scattering of sound energy in multiple directions upon striking an irregular surface. Diffusion distributes reflections evenly throughout a space, reducing flutter echoes and discrete reflections while preserving the room's natural ambience and liveliness.
In Simple Terms
Panels with uneven surfaces that scatter sound in every direction instead of absorbing it. Absorption makes a room dead and dry; diffusion keeps it lively but controlled. Most studios use both — absorbers where you need accuracy, diffusers where you need life.
In Practice
A series of quadratic residue diffusers on the rear wall of a mixing room scatter the back-wall reflection into hundreds of smaller reflections, eliminating the harsh slap-back echo without making the room feel acoustically dead.
Sources & Verification
- Schroeder, M. R. — Diffuse Sound Reflection by Maximum-Length SequencesJournal of the Acoustical Society of America, 1975
- Cox, T. J. & D'Antonio, P. — Acoustic Absorbers and Diffusers (3rd ed.)CRC Press, 2016
- Everest, F. A. & Pohlmann, K. C. — Master Handbook of Acoustics (6th ed.)McGraw-Hill, 2015
Last verified: 2026-05-05