Maybe you’ve seen them in studios or rehearsal spaces and wondered what’s the purpose for all those pieces of wood. Maybe you’ve seen something alike in plastic or foam. Maybe you’ve even see the most primitive version of a diffusor (and somewhat an absorber) in the form of a lot of egg cartons on the walls. Either way, diffusion is a strong tool in building an acoustically treated music room!
So what’s a diffusor, and why does it help with the acoustics? Diffusors come in many different shapes, sizes and materials. Common for all of them is the varying height (and sometimes width) of the many individual pieces of material. See a picture of a Skyline diffusor. This helps the diffusor spread or diffuse the sound hitting the material. Diffusors are used to treat echoes and reflections while still maintaining the acoustic liveliness of the room. They are an excellent addition to absorption because they don’t take out all the sound energy, but rather re-direct the sound.
Imagine this: You’ve got your speakers setup in your room. Most likely it’s a square room, with somewhat of a bare back wall. When you’re mixing or listening to music the sound waves travel from the speakers all the way to the back wall. When they hit the back wall they won't just disappear. Try throwing a ball at a wall - It’ll jump right back at you and so will the sound waves. When they return, they can cause phase cancellation and eliminate different frequencies. By placing a diffusor on the back wall, the sound will be scattered around your room and remove the reflections.
The best thing about diffusors is they are quite simple to make yourself. It only takes time – but more on that subject in another article
Want to make one by yourself? Read our how-to article here.