Computer speakers, or multimedia speakers, are loudspeakers sold for use with computers, though usually capable of other audio uses. For an MP3 player. Most of these speakers have an internal amplifier and therefore require a power supply, which can be by a power supply often through an AC adapter, batteries or a USB port (able to supply no more than 2.5 W DC, 500mA to 5V). The signal input connector is usually a 3.5 mm male connector (usually green in green color for PC 99 standard); Sometimes RCA connectors are used and a USB port can supply both signal and power (requires additional circuitry and is only suitable for use with a computer). Battery powered wireless Bluetooth speakers do not require a connection. When the external speakers are connected, they disable the built-in speakers. Altec Lansing claims to have created the computer speaker market in 1990.
Computer speakers vary widely in quality and price. Computer speakers, sometimes packaged with computer systems, are small, plastic and have mediocre sound quality. Some computer speakers have equalizer functions such as bass and treble controls.
More sophisticated computer speakers can have a subwoofer unit, to improve bass output. The larger subwoofer housing usually contains the amplifiers for the subwoofer and the left and right speakers.
Some computer screens have built-in basic speakers. Laptops have built-in integrated speakers, usually small and of restricted sound quality to conserve space.
Instead of using a computer speaker for better sound, a computer can be connected to any external sound system, usually a high-power, high-quality configuration.