Acoustic Modelling
Porous Absorber Calculator
Helmholtz Absorber Calculator
Multi-layer Absorber Calculator
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20 50 100 200 500 Frequency (Hz) 0 0.2 0.4 0.6 0.8 1 Absorption Coefficient
Absorption
Coefficient
Reflection
Coefficient
Impedance
(real)
Impedance
(imag)
Amend
Parameters
Global Parameters
Air temperature: 20°C
Air pressure: 101325 Pa

X Axis: Frequency
Range: 20Hz - 500Hz
Scale: logarithmic
Resolution: medium

Angle of incidence: 0°
Porous model: Komatsu (2008)
Helmholtz model: Ingard/Allard
Absorber Parameters
Absorber 1
75mm Slotted Panel, 3.5mm/50mm (7.00%)
400mm Porous Absorbent, 4000 Pa.s/m2
25mm Air
Rigid backing
Absorber 2
75mm Slotted Panel, 1.5mm/48mm (3.12%)
400mm Porous Absorbent, 4000 Pa.s/m2
25mm Air
Rigid backing
Absorber 3
75mm Slotted Panel, 6.5mm/55mm (11.82%)
400mm Porous Absorbent, 4000 Pa.s/m2
25mm Air
Rigid backing
Absorber 1: Peak absorption at 57.7Hz. Damping=1.62 (high)

Absorber 2: Peak absorption at 40.8Hz. Damping=1.94 (high)

Absorber 3: Peak absorption at 71.4Hz. Damping=1.58 (high)