Applicability of analytical models to design non-rectangular rooms at the low-frequency range

Abstract

For the exact calculation and acoustic design of rooms in the low-frequency range, it is necessary to use numerical simulation tools, whose cost and difficulty of use are obstacles faced in the daily routine of acoustic engineers/designers. In order to analyse the applicability of analytical models (simpler and cost-effective), this research study compares, in reduced-scale models (1:8), possible acoustic room formats (rectangular and non-rectangular) using two low-frequency analysis methods. Comparisons are made between the acoustic parameters T₂₀, EDT, C₈₀, D₅₀ and T_s, extracted by computational models using the Finite Element Method (FEM) and obtained by an analytical model. Through Pearson’s correlation coefficient (r), this study also evaluated the similarities between the analytical and computational models for the Energy Decay Curves EDC, the Frequency Response Function (FRF) H(f), and the impulse responses h(t). The results show that for non-rectangular rooms, the project requires highly accurate FRF analysis and impulse response, the use of numerical analysis methods becomes essential.