Diffusion

Until fairly recently, your acoustical room treatment options were generally limited to reflection and absorption. Diffusion, the scattering or redistribution of acoustical energy, was recognized as being sonically beneficial, but was also difficult to achieve.

All that changed about 20 years ago when a company called RPG Diffusor Systems began developing innovative diffusion products based on mathematical number theory.

The advantage of diffusion is that because the sound energy is scattered rather than absorbed, that energy isn't lost, thereby maintaining more of a "live" sound in your room.

It's difficult to describe this type of diffusion because it is completely rooted in advanced mathematics. But it has created a revolution in sound treatment that touches nearly every aspect of sound production and reproduction, from world-famous concert halls to top-flight recording studios and broadcast facilities.

Tips on diffusive treatments
Diffusion products can be used to treat many of the same problems that absorption is used for. Again, diffusion will rid your room of echoey reflections without replacing them with acoustic deadness.

Here are some situations where diffusion works particularly well:

A bookcase filled with odd-sized books makes a very effective sound diffusor.

• If your room already has built-in absorption in the form of carpeting, drapes, or acoustic ceiling tile, diffusion may control side wall reflections better than adding more absorption.
• You may already have a good natural diffusor in your home without realizing it. A bookcase filled with odd-sized books makes an effective diffusor.
• In a home theater system using traditional bookshelf speakers for surrounds, place diffusors in the middle of the back wall and aim your surrounds toward the diffusors at a 45° angle (see below).
• One of the best-sounding setups for music or home theater is to use absorptive material on room surfaces between your listening position and your front speakers, and treat the back wall with diffusive material to re-distribute the reflections.

If you're using conventional (non-dipole) surround speakers in a home theater system, you can achieve much of the diffuse sound of dipole speakers by treating your rear wall with diffusors and aiming your surrounds at them.