Sound absorption testing in the reverberation room
Traceable — not in accredited scope
Random-incidence absorption on a full-size specimen in the reverberation room. Reported per one-third-octave band, with the single-number rating your specifier asked for: αw and absorption class to ISO 11654, or NRC and SAA to ASTM C423.
What we test
- Acoustic panels and wall absorbers
- Suspended ceiling tiles and rafts
- Mineral wool, glass wool and foam insulation
- Carpets, underlays and textile floor coverings
- Curtains and drapes
- Automotive and transport interior materials
- Perforated and micro-perforated panels
Mounting changes the number more than the material does
The same 50 mm absorber mounted directly against a rigid backing (Type A) and mounted with a 200 mm air gap (Type E-200) can differ by several tenths of an absorption coefficient at low frequency. Neither result is wrong. If you publish an αw obtained with an air gap and your customer installs the product flat against concrete, you have a warranty problem, not a laboratory problem. Tell us how the product is actually installed and we will test it that way.
Reverberation room
- Specimen area
- 10–12 m² per ISO 354
- Mounting options
- Type A (direct), Type E-200 (200 mm air gap), Type J (suspended grid)
- Frequency range
- 100–5,000 Hz, one-third-octave bands
- Room qualification
- ISO 354 Annex A
- Reported quantities
- αs per band, αp, αw + class (ISO 11654), NRC + SAA (ASTM C423)