Membrane Absorber Calculator

The Membrane (Panel) Absorber calculator computes the resonant frequency and absorption characteristics of a construction consisting of a thin rigid panel mounted in front of a hermetically sealed air cavity. The panel vibrates as a membrane under sound pressure, converting sound energy into heat through internal material damping and viscous air friction in the cavity. Key calculation parameters are the panel surface mass (kg/m²) and the air cavity depth. Why it matters: membrane absorbers are effective in the 50 – 300 Hz range — exactly where porous materials fall short due to insufficient thickness. They are thinner than mineral-wool bass traps and significantly easier to integrate into interior design without consuming much space. This construction is widely used in professional studios, home theaters, and rehearsal spaces. How to read results: the resonant frequency is the frequency of peak absorption. It is determined by the panel mass and the air cavity depth: the heavier the panel and the deeper the cavity, the lower the resonance. The calculator shows how changing each parameter shifts the tuning frequency. The absorption coefficient at resonance can reach 0.6 – 0.9 with proper damping material inside the cavity. Common mistakes: choosing a panel that is too thick and heavy, which pushes the resonant frequency below the target; a leaky cavity that causes the absorber to lose effectiveness; omitting a damping layer (mineral wool or felt) inside the cavity. Next steps: compare the result with a Helmholtz resonator at the same frequency. Use the Multi-layer absorber calculator to widen the operating range of the construction.