What controls absorption frequency?

Perforation mass (hole size and open area) and cavity depth behind the panel.

Perforated Panel Absorber — v5.34

Basic

Units

Target frequency (Hz)

Width W

Height H

Depth D (external)

More features in Advanced:

Bandwidth (BW) and full frequency chart
Optimize with locked fields — fill only what you must
Max total depth (D_max) limit and one‑click depth suggestions
Bandwidth preference (Wide / Neutral / Narrow)
Flow resistivity for porous material
Control hole diameter d, open area φ, or pitch
Porous thickness (standard sizes) and air gap
Constraints: Min edge gap and Max holes
Custom chart range & units
No Ads

Results

Assume panel & back are same thickness t = 18 mm → internal cavity D_int = total − 2t.

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Peak f (Hz)

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Max α

See Advanced

Bandwidth & full chart available in Advanced.

Advanced

Leave a field empty to let the optimizer decide it. Any filled field is locked.

Units

Target frequency (Hz)

Panel width W

Panel height H

Panel thickness t

Flow resistivity (kPa·s/m²)

Hole diameter d

Open area φ (%)

Pitch (square)

Total depth D (external)

Max total depth D_max (external)

Porous thickness

Min edge gap

Max holes

Target tolerance

Custom ±% (if selected)

Bandwidth preference

Chart range (Hz)

Optimization: (neutral) min total depth → min holes → max α@fₜ → min df. (wide/narrow): BW first.

Results (Advanced)

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Peak f (Hz)

–

Max α

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BW (≥0.5·αmax)

How the perforated panel absorber calculator works

Basic and advanced modes optimize hole diameter, open area, cavity depth, and panel area for target absorption frequency and bandwidth-based on Helmholtz resonator physics and flow resistance.

Key terms

Open area ratio - percentage of panel surface that is perforated.
Cavity depth - air space behind panel; sets compliance and tuning.
Flow resistivity - damping inside cavity; widens absorption peak.

Frequently asked questions

What controls absorption frequency? Perforation mass (hole size and open area) and cavity depth behind the panel.