A Note on the Resonance Frequency Equation of Microperforated Panel Sound Absorber



Helmholtz resonators, microperforated panel absorber, resonance frequency, , mass reactance, acoustic resistance, perforation constant.


Microperforated panel, MPP, can be considered as a multi or N-holes Helmholtz resonator. It is a light, clean and tunable sound absorber, for which a first modeling was established by Maa in 1975. It is a resonator in sub-millimeter size of diameter (0.5–1) mm, to provide enough acoustic resistance and low acoustic mass reactance which are necessary for wide-band sound absorber. The characteristic property of such a resonator is its ability to absorb sound waves of a particular frequency, the so-called resonant frequency. In practical and engineering applications, for prefabricated microperforated panel, it is important to determine the resonance frequency as precisely as possible, especially if the panel will be used as a sound absorber at a certain frequency. There is high deviation between the exact resonance frequency value of single MPP absorber which can be obtained from the peak of calculated absorption curve by Maa’s equation and that value which can be calculated by the classical N-holes Helmholtz resonance frequency equation. A proposed modified and simplified equation for calculating the resonance frequency of single MPP sound absorber of hole diameter (0.5–1) mm, which derived from absorption equation of Maa, is introduced. The new proposed equation gave good agreement and little deviation, maximum deviation was about 5 Hz over frequency range from 50 Hz to 1000 Hz, from the exact value of resonance frequency.



How to Cite

Abd-Elbasseer M, Teleb H. A Note on the Resonance Frequency Equation of Microperforated Panel Sound Absorber. Canadian Acoustics [Internet]. 2024 Apr. 1 [cited 2024 Apr. 23];51(4):7-13. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/3945



Article - Engineering Acoustics / Noise Control

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