THEORETICAL PREDICTIONS OF SOUND SCATTERING COEFFICIENT AND SOUND DIFFUSION COEFFICIENT FROM QUADRATIC RESIDUE DIFFUSERS

Abstract

Quadratic residue diffuser (QRD) is a device that distributes the acoustic energy of intense reflections by its spatial and temporal dispersion. The quadratic residue diffuser consists of a series of wells of different depths and the same width. Optimal diffusion is very important for perceiving musical sound and eliminating unwanted acoustic effects e.g. echoes. For the purpose to determine the optimal diffusion, Schroeder used mathematical number sequences allowing to diffuse the sound in a semicircular pattern from the devices. In this paper, the presented quadratic residue diffuser modeling method is presented. Result of theoretical modeling at a frequency of 500 Hz was obtained. The estimated width of the wells is 9.4 cm. The sound scattering and sound diffusion coefficient different number of the diffusor wells were researched. It was obtained that with an increasing number of wells of the diffuser leads to an increment in sound diffusion at the design frequency for diffuser the same width sequences.