Systematische Untersuchungen zur Funktionsweise des Kantenabsorbers als „Modenbremse“

Today’s knowledge about the acoustic influence of edge absorbers on a sound field is mainly based on empirical experience. Unfortunately, since there is no computational model for edge absorbers, this type of absorber is only hesitantly used in room acoustic design.
This contribution systematically investigates the absorption behavior of edge absorbers and proposes an approach for a computational model for edge absorbers in simple room geometries. A modular edge absorber was developed and constructed for systematic investigations. In the development process, optimal parameters for flow resistance, the perforation ratio of the absorber housing and the layer thickness of the incorporated porous material were found. Due to the modular design principle of the developed edge absorber, a flexible assembly is possible.
Various configurations of the modular edge absorber were measured in the reverberation chamber. The acoustic behavior of the edge absorber was determined in several lecture halls. It was found that the equivalent absorption area per unit of length and the lower frequency limit of the edge absorber are dependent on the assembly depth and the particular mounting edge of the edge absorber. In addition, the bandwidth for effective absorption depends on the dimensions of the edge absorber.
The modular edge absorber was used in a room acoustic renovation and pre-post measurements were performed to confirm the effectiveness of the edge absorber.