G.4 Diffusers
A diffuser provides diffuse reflection of the sound radiated against it. It can be a very useful solution in cases where reflections are disturbing the sound image and it is not advisory to add further absorption. So in order to reduce flutter echoes, comb filtering etc., special elements can be placed on the "disturbing" surface. These elements must have dimensions comparable to the frequencies at which diffusion is wanted.
Often bookshelves stocked with books of irregular sizes and/or music collections (LP's or CD's) can act as
G.4.1 Absorption or Diffusion ?
A special technique developed by Manfred Schroeder is very capable in making a smooth and controlled diffusion. These diffusers normally referred to as "Schroeder Diffusers" can be found as readily made modules.
Schroeder type Diffusor
G.4.2 Absorbers
All materials in the room act acoustically even if they are not specially designed acoustical materials. In domestic situations we have generally two types of absorbers.
G.4.2.1 Membrane absorbers
This kind of absorber includes wooden floors, windows, doors, etc. This absorber provides absorption in the low end of the frequency range. The efficiency is normally not very high, but under normal conditions large areas are included in the basic room construction. Special designed membrane absorbers can be very effective. Placing a wood laminate floor on suitable acoustic backing can provide one such absorber.
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