Qualifying freefield and reverberation rooms for frequencies below 100 Hz

摘要

Laboratory measurements at frequencies below 100 Hz of sound power, absorption and transmission are hampered by the presence of various resonance phenomena at the room's eigenfrequencies and the lack of suitable acoustic lining material. In its extensive efforts to create non-fibrous, compact and robust alternatives to the conventional absorbers, IBP has developed, among others, a special broadband resonant absorber which shows an amazingly high absorption efficiency down to 20 Hz with a total lining thickness of only 250 mm.