In physics, a pair of equal and opposite electric charges or magnetic poles that are separated by a small distance. This term has been adapted to cover audio and video concepts in two different ways.
In audio a dipole loudspeaker contains two drivers, usually directed 180 degrees in opposition to each other and wired in opposite phase to each other. Dipole loudspeakers are often found in home theater surround systems where they serve as rear (and sometimes side) satellites. Their donut shaped dispersion pattern can be effective for enhancing the sensation of envelopment that is an important part of the surround experience.
In radio and television, a dipole antenna is an aerial half a wavelength long consisting of two rods connected to a transmission line at the center. The most common example of this is the “rabbit ears” antenna that is often used to pick up local television broadcasts. Many wireless monitor and assistive listening system transmitters use dipole antennas.