direct-radiator dynamic loudspeaker (direct-radiator)

The vibrating system of the dynamic direct-radiator loudspeaker is composed of a conical paper diaphram coupled to a voice coil located in a magnetic field. When a current is caused to flow in the voice coil by the application of a voltage, a force is produced by the interaction of the current and the magnetic field which corresponds to the applied voltage. This force is transmitted to the diaphragm and, thus, produces motion of the coil and diaphragm. The diaphragm's motion produces sound waves. (p.336 from Music, Physics, and Engineering, by Harry F. Olson.)