Enhancing Microperforated Panel Absorption by Subdividing the Backing Airspace into Channels and Resonators

It is well known that microperforated panel absorbers are easily tuned by varying the backing cavity depth. It has been shown that dividing the airspace behind the microperforated panel absorber into smaller channels of varying length can greatly improve the sound absorption performance. Several variations of this strategy are examined in this paper. Plane wave analytical models are used to develop the absorbers and results are compared with measurement with good agreement. Sound absorbers are developed which improve the low frequency and broadband sound absorption performance of a microperforated panel with no special backing.