TYPICAL ABSORPTION COEFFICIENTS
Material	125Hz	250Hz	500Hz	1 kHz	2 kHz	4 kHz
Acoustic Panelling	0.15	0.3	0.75	0.85	0.75	0.4
Acoustic Tiles	0.1	0.35	0.7	0.75	0.65	0.5
Brick	0.024	0.025	0.03	0.04	0.05	0.07
Carpet thin	0.05	0.1	0.2	0.25	0.3	0.35
Carpet thick with underlay	0.15		0.35		0.5
Chair padded dining	1.0		2.5		3.0
Chair upholstered	2.5	3.0	3.0	3.0	3.0	4.0
Concrete	0.01	0.01	0.02	0.02	0.02	0.03
Curtains	0.05	0.12	0.15	0.27	0.37	0.5
Curtains heavy with folds	0.2		0.5		0.8
Door wooden	0.3		0.15		0.05
Fibreglass 1in	0.07	0.23	0.42	0.77	0.73	0.7
Fibreglass 2in	0.19	0.51	0.79	0.92	0.82	0.78
Fibreglass 4in	0.38	0.89	0.96	0.98	0.81	0.87
Floor wood no joints	0.15	0.2	0.1	0.1	0.1
Floor wood blocks	0.05		0.05		0.1
Glass	0.03	0.03	0.03	0.03	0.02	0.02
Person seated	0.18	0.4	0.46	0.46	0.5	0.46
Plasterboard	0.3		0.1		0.04
Plaster on lathe	0.3		0.1		0.04
Plaster on brick	0.024	0.027	0.03	0.037	0.039	0.034
Plywood 3/4in	0.11		0.12		0.1
Plywood 3/16in on 2 batten	0.35	0.25	0.2	0.15	0.05	0.05
Wood 3.4in solid	0.1	0.11	0.1	0.08	0.08	0.11

Description

125 Hz

250 Hz

500 Hz

1k Hz

2k Hz

4k Hz

Floor, wood parquet		0.04	0.04	0.07	0.06	0.06	0.07
Curtains heavy with folds		0.20		0.50		0.80
Carpet thick with underlay		0.15		0.35		0.50
Floor, carpet, 1/8" pile		0.05	0.05	0.10	0.20	0.30	0.40
Floor, carpet. 1/4" pile		0.05	0.10	0.15	0.30	0.50	0.55
Floor, carpet, 5/16" pile		0.05	0.15	0.30	0.40	0.50	0.60
	Carpet, 3/32" pile	0.10	0.16	0.11	0.30	0.50	0.47
	Carpet, 3/4" pile	0.15	0.17	0.12	0.32	0.52	0.57
	Carpet, 3/8" pile	0.17	0.18	0.21	0.50	0.63	0.83
	Carpet, 6/16" pile, 40oz/yd2, on hair pad	0.03	0.25	0.55	0.70	0.62	0.84
	Carpet, 6/16" pike, 86oz/yd2, on hair pad	0.10	0.40	0.62	0.70	0.63	0.88
	Carpet, 6/16" pike, 86oz/yd2, on hair and jute pad	0.20	0.50	0.68	0.72	0.65	0.90
	Carpet, 20oz/yd2 , loop pile (no pad)	0.04	0.08	0.17	0.33	0.59	0.75
	Carpet, 40oz/yd2, hair pad	0.10	0.19	0.35	0.79	0.69	0.79