Loudspeaker servo control via amplitude measuring device - uses pneumatic pressure transducer responsive to internal vol. of loudspeaker housing

摘要

The loudspeaker servo control employs an amplitude measuring device. The loudspeaker (3) is inserted across an opening in one wall of an air-tight loudspeaker housing (5), the amplitude measuring device comprising a pneumatic pressure transducer (7) coupled to the internal volume of the loudspeaker housing (5) for measuring air pressure variations caused by the motion of the loudspeaker cone. The pressure transducer may comprise a pressure capsule, with a piezoelectric membrane suspended via springs (15) within the loudspeaker housing.