n'H Akustik + Design Topakustik 12/4 HR wood absorber

Topakustik – 12/4 HR

PTB reference data

Original description

Material properties

Manufacturer: n'H Akustik + Design AG

Wall distance: 7.9 in

Density: 60 kg/m³

Perforation: 15 %

Backing: 1.2 in mineral wool

Reverberation chamber (ASTM C423 / ISO 354)

NRC

0.90

derived from ISO 354 lab data

α_p nach ISO 11654

f (Hz)	125	250	500	1k	2k	4k
α_p	0.30	0.80	0.95	1.00	0.80	0.65

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Value from the PTB table, not verified

NRC: 0.90 (derived from ISO 354 lab data)

Measured values as a table (1 measurement)

n'H Akustik + Design Topakustik 12/4 HR wood absorber: sound absorption coefficient αs per ISO 354 by frequency and test build-up
Build-up	NRC	125 Hz	250 Hz	500 Hz	1000 Hz	2000 Hz	4000 Hz
200 mm	0.90	0.31	0.80	0.96	1.02	0.78	0.64

Measured values as a table (1 measurement)

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Last updated: 09/07/2026