ACOUSTIC TRANSDUCER Russian patent published in 1998 - IPC

FIELD: loud speakers for playing voice, music and other sounds. SUBSTANCE: device has magnetic circuit which is designed as two steel plates which are covered with rows of flat identical permanent magnets with mirrored orientation. Flat dielectric diaphragm is located between magnets on support which is designed as two plates with central holes. Both sides of diaphragm are covered with flat sound coils. Fill factor of magnetic system and size of magnets conform to condition , where W_g is distance between rows of magnets on plate, W_m is width of magnet. Shape and size of central holes of plates of support correspond to shape and size of working surface of diaphragm and size of field covered by magnet on surface of each plate of magnetic system. EFFECT: increased functional capabilities in wide frequency range. 3 cl, 2 dwg