Investigation of Low-Frequency Sound Colouration Treatments in Small Rooms by Means of Finite Element Analysis

Abstract

Acoustics in small rooms suffer from resonances in low frequencies, resulting in the well-known sound colouration problem. In the present work, the finite element method was used to investigate specific case studies of proposed treatments of this problem. The treatments are based on techniques that make use of three basic mechanisms: wavelength, boundary impedance, and active control. The quality of the treatments is evaluated using two spatial statistical measures of the sound pressure level frequency responses regularly sampled in the listening area. The results demonstrate the advantage of the impedance-and active control mechanism-based techniques. Resonant panels and multiple source excitation treatments improve the sound field flatness.

Archives of Acoustics

“…The radiation pattern of a compound source is adapted by changing the driving parameters of the comprising sources, resulting in narrower radiating lobes comparing to monopole sources. The change of acoustic pattern towards different directions was confirmed in the free field, with the investigation of various compound source topologies (Sevastiadis et al, 2014). In the same work, it was verified that the adaptive radiation of a compound source can control a modal field and highly directive sources can provide more efficient sound field control, as it was tested for an axial mode excitation in a room model.…”

A validated finite element model for room acoustic treatments with edge absorbers

“…Thus, numerical wave-based methods must be employed to properly model wave phenomena and the influence of edge absorbers. The Finite Element Method (FEM) presents an appropriate tool and has been used to model low-frequency room acoustics, as the following examples illustrate: In [18], a FEM simulation of a small studio is presented using a commercial FEM code where acoustic absorbers were modeled using surface impedances. A two-dimensional FEM for modeling the acoustic effect of micro-perforated panels has been presented in [19], where a dedicated finite element type was introduced for modeling micro-perforated panels.…”