Patent ID: 7433487

Claim:
A speaker comprising: a frame; a diaphragm supported by the frame; a magnetic circuit portion including a magnet and a yoke portion opposed to the magnet; and a coil disposed in a gap between the magnet and the yoke portion, the coil moving along with the diaphragm; wherein a surface of the magnet opposed to the yoke portion includes a first magnetized portion disposed at one side of the surface of the magnet in the moving direction of the coil and a second magnetized portion disposed at an opposite side of the surface of the magnet, the first and second magnetized portions have the same magnetic polarity, the surface of the magnet opposed to the yoke portion includes a central portion disposed between the first magnetized portion and the second magnetized portion, and the central portion has a magnetization that is weaker than the first magnetized portion and the second magnetized portion.