PURPOSE: To obtain an efficient moving magnet type induction speaker by arranging a dome-shaped vibration plate having a conductive short circuit ring adjacently to a moving magnet.
CONSTITUTION: Adjacently to the moving magnet, for example inside it, a dome- shaped vibration plate 6 having the conductive short circuit ring is provided. A moving magnet type induction speaker 15, by inputting a signal current to a fixed coil 3, vibrates a moving magnet 9 and a short circuit ring 4 corresponding to an input signal, and the vibration is converted into a sound wave through a vibration plate 12 provided to the moving magnet 9 side and a dome type vibration plate 6 provided to the short circuit ring 4 side then emitted. Thus, without increasing the number of turns of the fixed coil and without enlarging the energy product of the magnet, the efficient moving magnet type dynamic guide speaker can be obtained.
WO/2000/021329 | HIGH FIDELITY, BROAD BAND ACOUSTIC LOUDSPEAKER |
WO/2015/022817 | HEADPHONE AND ACOUSTIC CHARACTERISTIC ADJUSTMENT METHOD |