DIFFUSER DESIGN FOR LATERAL WALLS IN A CONCERT HALL USING SCALE MODELS

Abstract

Surface diffusivity of lateral walls affects the distribution of a sound field on concert hall acoustics. The design elements of diffusers in concert halls are diffuser’s geometrical shape, structural height, surface coverage, and installation position. Scattering and diffusion coefficients of the diffusers were measured in a 1:10 reverberation chamber. The diffusers were applied to scale model concert halls with different design elements of diffusers. Acoustical parameters such as RT, EDT, C80, and G were calculated from the impulse responses. In addition, the numbers peaks (Np) within -20 dB from the amplitude of direct sound were calculated to evaluate the diffuseness in the halls. As results, diffusers caused decrease of RT, EDT and G, and contributed to decrease of relative standard deviations (RSD) of the parameters. It was also found that the diffusive lateral walls close to the stage area are effective in increasing Np.