Numerical simulations of the modified Schroeder diffuser structure

Abstract

Schroeder diffusers are widely used in architectural acoustics because they offer unique diffusion characteristics. It has been recently shown that the Schroeder diffusers are also efficient low-frequency absorbers. In this paper a new modified Schroeder diffuser structure is presented. The new folded structure allows one to extend the low-frequency limit of the Schroeder diffuser so that the cutoff frequency is not directly proportional to the depth of the structure. Other important advantage of the new structure is that the total volume of the structure is fully utilized as a diffuser. The modified structure is also easier to manufacture than the traditional Schroeder diffusers. The modified structure is compared with the traditional ones by numerical simulations and measurements. Both the radiation and absorption characteristics are modeled. Modeling techniques, such as finite element and boundary element method and finite difference time domain methods, are applied and compared with each other.