Multi-layer Absorber Calculator

The Multi-layer Absorber calculator models acoustic constructions that combine porous and resonant layers to achieve broadband absorption. A typical multi-layer system might include a perforated face panel, an air gap, a mineral wool layer of specified density, another air gap, and a rigid back wall. Each layer contributes to the overall absorption curve, and the calculator shows both the total result and individual contributions. Why it matters: single-type absorbers work within a limited frequency range. Porous material performs well at mid and high frequencies; membrane constructions at low frequencies. A multi-layer system can cover the entire working range from 80 Hz to 4000 Hz in a single panel of reasonable total thickness — typically 100 to 200 mm. This is the key approach in professional acoustic treatment of studios and critical listening environments. How to read results: the calculator displays the total absorption coefficient by frequency and the contribution of each individual layer. Look for "gaps" — frequencies where none of the layers works effectively. By varying layer thickness and face panel perforation size, you can fill these gaps. Common mistakes: too many thin layers that provide no real low-frequency absorption; incorrect layer order — the perforated panel must always face the room; choosing fill material without considering its airflow resistivity. Next steps: calculate each layer individually for verification, and use the Treatment Planner to place the finished multi-layer construction in the room.