Design acoustic metamaterial absorbers using the Transfer Matrix Method. Stack Helmholtz resonators, quarter-wavelength tubes, and micro-perforated panels — compute absorption spectra, surface impedance, and NRC ratings in real time. All physics runs client-side in your browser.
[pin, vin]T = ∏ Tlayer · [pout, vout]T
Each acoustic layer contributes a 2×2 transfer matrix based on characteristic impedance Zc and propagation constant k. Rigid backing gives α(f) = 1 − |R(f)|².
fres = (c/2π)√(Sneck/(V·leff))
Neck impedance with viscous losses, radiation resistance, and end corrections. Cavity modeled as lumped compliance.
ZMPP = R(φ, d, t) + jX(ω, d, t, φ)
Analytical impedance from perforation ratio, hole diameter, and panel thickness with viscous and edge effects.