Scale Model Investigations of Diffuser Application Strategies for Acoustical Design of Performance Venues

This work investigates the effects of diffusive surfaces on concert hall acoustics using scale models with regard to hall shape and diffuser location. Two simple 1:50 scale models (shoebox and fan-shaped) were produced to measure the RT and SPL, which were decreased by wall diffusers in both hall shapes. In the shoebox hall, SPL was increased especially in the frontal area but was decreased in the rear area due to redirection of the second reflections by the opposite lateral walls, whereas SPL was decreased in both the frontal and rear area in the fan-shaped hall. For in-depth investigation of diffuser location and profile, three shoebox model halls were reproduced: a 1:50 symphony hall, a 1:25 chamber hall and a 1:25 theater. Minimal reductions in RT and LL and decreased spatial deviation in acoustical parameters were established as criteria to determine the effective diffuser location. The halves of the lateral walls closest to the stage were found to be the most effective areas for diffuser installation. Additionally, large and sparse diffuser profiles usually provided better acoustical results.