WoodHighly absorbent

Physikalisch-Technische Bundesanstalt

Source: Manufacturer data online at http://www.bau-online.at/kataloge/123240/akustik/absorb_t.htm, 02.02.2001

Value from the PTB table, not verified

Isolith BAB® sound absorber panel per ÖNORM B 6021, thickness 50 mm

BAB® sound absorber panel per ÖNORM B 6021

PTB reference data

Original description

Material properties

Manufacturer: Isolith M. Hattinger Ges.m.b.H.

Thickness: 2 in

Backing: non-combustible stone wool core with vertically arranged fibers

Surface: approx. 0.3 in cement-bound wood wool coating

Up to fire class: non-combustible

Reverberation chamber (ASTM C423 / ISO 354)· 2 variants

NRC

1.00

α_p per octave band

f (Hz)	125	250	500	1k	2k	4k
α_p	0.55	0.90	1.00	1.00	1.00	0.95

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Compare		Value
	grobe Wollstruktur	NRC1.00
	feine Wollstruktur	NRC1.00

NRC: 1.00 (derived from ISO 354 lab data)

Application: installation with Hilfe eines Abhängsystems

Measured values as a table (2 measurements)

Isolith BAB® sound absorber panel per ÖNORM B 6021, thickness 50 mm: sound absorption coefficient αs per ISO 354 by frequency and test build-up
Build-up	NRC	100 Hz	125 Hz	160 Hz	200 Hz	250 Hz	315 Hz	400 Hz	500 Hz	630 Hz	800 Hz	1000 Hz	1250 Hz	1600 Hz	2000 Hz	2500 Hz	3150 Hz	4000 Hz	5000 Hz
50 mm · installation with Hilfe eines Abhängsystems · grobe Wollstruktur	1.00	0.48	0.56	0.63	0.75	0.87	1.04	1.02	1.01	1.04	1.11	1.11	1.19	1.14	1.09	1.01	0.98	0.96	0.95
50 mm · installation with Hilfe eines Abhängsystems · feine Wollstruktur	1.00	0.46	0.58	0.61	0.76	0.90	0.98	1.05	0.98	1.00	1.02	1.08	1.17	1.16	1.10	1.14	1.08	1.00	1.03

Measured values as a table (2 measurements)

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Last updated: 09/02/2026