Patent ID: 6907955

Claim:
An electromagnetic electroacoustic transducer, comprising: a diaphragm made of a magnetic material; a magnet for generating a magnetostatic field to make the magnetostatic field act on the diaphragm; an electromagnetic coil for generating an oscillating magnetic field corresponding to an electric signal to make the oscillating magnetic field act on the diaphragm; a casing for storing the diaphragm, the magnet and the electromagnetic coil therein; and a lead terminal connected to a coil terminal of the electromagnetic coil, wherein the case has at least one first sound emitting hole through which a front space on a front surface of the diaphragm in the casing communicates with a front outer space in front of the casing and at least one second sound emitting hole through which a rear space on a rear surface of the diaphragm in the casing communicates with the front outer space in front of the casing through a space provided to a portion at which the lead terminal and the coil terminal are connected; and a resonant frequency Fv 2 of the rear space is set at a value in the range: F 0 <Fv 2 ≦Fv 1 in which F 0 is a resonant frequency of the diaphragm, and Fv 1 is a resonant frequency of the front space.