Speaker (audio equipment) in the context of "Dynamic microphone"

An electrodynamic speaker driver, often called simply a speaker driver when the type is implicit, is an individual transducer that converts an electrical audio signal to sound waves. While the term is sometimes used interchangeably with the term speaker (loudspeaker), it is usually applied to specialized transducers that reproduce only a portion of the audible frequency range, or to the one or more drivers within a loudspeaker cabinet (or simply "speaker".). For high fidelity reproduction of sound, multiple loudspeakers are often mounted in the same enclosure, each reproducing a different part of the audible frequency range. In this case the individual speakers are referred to as drivers and the entire unit is called a loudspeaker. Drivers made for reproducing high audio frequencies are called tweeters, those for middle frequencies are called mid-range drivers (much less commonly called squawkers), and those for low frequencies are called woofers, while those for very low bass range are subwoofers. Less common types of drivers are supertweeters and rotary woofers.

The electroacoustic mechanism most widely used in speakers to convert the electric current to sound waves is the dynamic or electrodynamic driver, invented in 1925 by Edward W. Kellogg and Chester W. Rice, which creates sound with a coil of wire called a voice coil suspended between the poles of a magnet. There are others that are far less widely used: electrostatic drivers, piezoelectric drivers, planar magnetic drivers, Heil air motion drivers, and ionic drivers, among other speaker designs.

Computer speakers, or multimedia speakers, are speakers marketed for use with computers, although usually capable of other audio uses, e.g. for a shelf stereo or television. Most such speakers have an internal amplifier and consequently require a power source, which may be by a mains power supply often via an AC adapter, batteries, or a USB port. The signal input connector is often an analog 3.5 mm jack plug (usually color-coded lime green per the PC 99 standard); RCA connectors are sometimes used, and a USB port or Bluetooth antenna may supply a digital signal to an onboard DAC (some of which work only on computers with an appropriate device driver). Battery-powered wireless speakers require no cables at all. Most computers have speakers of low power and quality built in; when external speakers are connected they disable the built-in speakers by default. Altec Lansing claims to have created the computer speaker market in 1990.

Computer speakers range widely in quality and in price. Computer speakers packaged with computer systems are typically small, plastic, and have mediocre sound quality. Some computer speakers have equalization features such as bass and treble controls. More sophisticated computer speakers can have a subwoofer unit to enhance bass output. The larger subwoofer enclosure usually contains the amplifiers for the subwoofer and the left and right speakers.

Audio equipment refers to devices that reproduce, record, or process sound. This includes microphones, radio receivers, AV receivers, CD players, tape recorders, amplifiers, mixing consoles, effects units, headphones, and speakers.

Audio equipment is widely used in many different scenarios, such as concerts, bars, meeting rooms and the home where there is a need to reproduce, record and enhance sound volume.