Low frequency loudspeaker armature - uses ferrite blocks as fixed component defining air gap for moving coil

摘要

Armature or driving mechanism for the diaphragms of loudspeakers. The design is esp. applicable to loudspeakers used at low, or very low frequencies and may be used with conical or plane surface diaphragms. The diaphragm (1B) is extended in both cases into a tube (9) which has a rectangular or circular cross-section, which carries a coil (8) of about six layers of windings. This coil in an air-gas defined by two enclosing walls of ferrite blocks (5A, 5B) the ferrite material having high coercive and demagnetising current characteristics. The block dimensions are such as to occupy approximately half the depth of the coil winding.