Automatic regulator for pass band linearity of electro acoustic appts. - operates without manual intervention by measuring level of generated sound

摘要

The device automatically regulates the passband linearity of an electroacoustic system, and comprises a microphone (3) at an optimum listening place supplying information to an equaliser (2) comprised of a number of filters. A noise generator (1) provides a reference signal transmitted through the equaliser to a chain of audio frequency appts. which transforms the signal into sound in turn detected by the microphone. The microphone is passed through a passband analyser (4), formed by filters, to comparators (5), which compare the filtered signals with a reference voltage (8) derived from a detector (6) monitoring all of the comparator outputs, the latter being applied to the equalisers. Depending on the analysis of the sound detected by the microphone, the equaliser filters are adjusted by the comparators to provide a desired optimum response curve.