Patent ID: 7561705

Claim:
A dynamic microphone, comprising: a cylindrical member including an air chamber having a predetermined volume therein, a magnetic circuit unit provided on one end of the cylindrical member, and including a yoke having a ring shape, a first permanent magnet mounted on the yoke and having a disk shape, the first permanent magnet being polarized in a thickness direction, and a center pole piece mounted on the first permanent magnet, the yoke surrounding the center pole piece for defining a magnetic gap with a predetermined width therebetween, a diaphragm provided on the magnetic circuit unit, and having a peripheral portion supported by a periphery of the magnetic circuit and a voice coil disposed in the magnetic gap to vibrate therein, a resonator disposed so as to substantially entirely cover the diaphragm and having a front acoustic terminal, and a second permanent magnet disposed on the resonator so as to face the center pole piece, and having a diameter substantially same as that of the first permanent magnet, said second permanent magnet being polarized in a thickness direction and having a lower surface as a pole same as that of an upper surface of the first permanent magnet.