Researchers from North Carolina State University and Nanjing University have developed an “ultra-thin” sound diffuser that is 10 times thinner than the widely used diffusers found in recording studios, concert venues and movie theaters to reduce echoes and improve the quality of sound. The new design uses less material, which would reduce cost, as well as taking up far less space.
The most widely used diffusers, called Schroeder diffusers, can be very bulky. That’s because the size of a diffuser is governed by the wavelength of the sound it needs to diffuse. Specifically, the depth of a Schroeder diffuser is about half of the wavelength of the lowest sound it needs to diffuse.
For example, a typical man’s voice can be as low as 85 hertz, with a wavelength of 4 meters or 13.1 feet. If that’s the lowest sound the Schroeder diffuser will have to deal with, the diffuser would need to be roughly 2 meters – or just over 6.5 feet – thick.
But the new, ultra-thin diffuser design requires a thickness that is only 5 percent of the sound’s wavelength. So, instead of being 2 meters thick, it would only be 20 centimeters – or less than 8 inches – thick.