FIELD: electromechanical transducers. SUBSTANCE: transducer has magnetic circuit with annular gap formed by its poles and power (sound) coil that can move when ac current is passed though it. Pole surfaces forming annular gap are covered with material of higher heat conductance than that of magnetic circuit. Heat-transfer surfaces contacting air in the gap are rough and have grooves. In some cases, grooves may be made in the form of grid with inclined longitudinal components. EFFECT: improved temperature conditions in coil-and- magnetic-circuit assembly which improves reliability and service life of transducer. 2 cl, 1 dwg
