Knauf D 127 perforated gypsum board with mineral fiber (series 2)

D 127 perforation 12/20/35R

PTB reference data

Original description

Material properties

Manufacturer: Knauf Hauptverwaltung Iphofen

Thickness: 12.5 mm (gypsum board), 20 mm (mineral fiber)

Wall distance: 60 mm, 400 mm

Perforation: 9.8%

Backing: 20 mm mineral fiber, standard non-woven

Mounting: on sub-frame

ISO 354 – reverberation chamber· 2 variants

α_w

0.45

α_p per ISO 11654

f (Hz)	125	250	500	1k	2k	4k
α_p	0.70	0.80	0.65	0.55	0.35	0.40

Create a permanent free account — Access frequency bands, variants and export.

Free. No password required.

Compare		Value
	400 mm	α_w0.45
	60 mm	α_w0.35

Weight / density: <15 kg / m²

Dimensions: 1200 mm x 1875/2500 mm

Measured values as a table (2 measurements)

Knauf D 127 perforated gypsum board with mineral fiber (series 2): sound absorption coefficient αs per ISO 354 by frequency and test build-up
Build-up	α_w	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
12,5 mm + 20 mm Mineralfaser · <15 kg / m² · 400 mm	0.45	0.54	0.64	0.86	0.80	0.82	0.79	0.64	0.67	0.69	0.65	0.55	0.45	0.40	0.32	0.30	0.37	0.42
12,5 mm + 20 mm Mineralfaser · <15 kg / m² · 60 mm	0.35	0.19	0.34	0.28	0.60	0.69	0.83	1.02	1.02	0.86	0.70	0.49	0.38	0.30	0.21	0.23	0.26	0.33

Measured values as a table (2 measurements)

Access frequency bands, variants and export. Create a permanent free account

Last updated: 02/09/2026