The distribution of income in California

An electro-acoustic transducer in which a voice coil having an axial length larger than the thickness of a yoke is disposed in the magnetic flux gap defined between a pole piece and the yoke, and an audio signal is applied to the voice coil for causing vibrations of the voice coil. In the electro-acoustic transducer, a short-circuit ring is disposed around the pole piece for cancelling the portion of a.c. magnetic flux which emanates from the voice coil and circulates through the magnetic circuit, so as to reduce second harmonic distortions appearing in the acoustic output signal.