Or speaker, a device to convert electrical impulses into
sound. It commonly comprises a rigid conical
diaphragm attached to a coil held such that it may move backward and forward;
within the cylinder of the coil is a fixed permanent magnet. Changes in
the current supplied to the coil alter its magnetic
field so that it, and the cone, vibrate to produce the compression waves
that are sound. High fidelity sets use two or more loudspeakers of different
sizes for more accurate reproduction.