Microphone assembly with main and secondary microphones - has series anti-phase connected microphones wiring connections with coaxial cable screens connected to common point to eliminate acoustic feedback problems

摘要

The assembly (3) has two parts (5, 6) which are mechanically and electrically linked by a three pin connector (4). The front part (5) contains a single main microphone (1). The rear part (6) contains another microphone (2), which protrudes above the centre line of the main part. The microphones have similar electrical characteristics and are connected in series in anti-phase. The screens of the internal coaxial cables are connected to a common point. Sounds from a nearby source are received differently by the two microphones, thus producing the useful output. Oscillating sounds from distant loudspeakers i.e. acoustic feedback is received by both microphones and is mutually cancelled out, because of the anti-phase connection.