Computer speakers, or multimedia speakers, are external speakers, commonly equipped with a low-power internal amplifier. The standard audio connection is a 3.5mm (1/8 inch) stereo jack plug often colour-coded lime green, folowing the PC 99 standard) for computer sound cards. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 200 milliamps provided by the USB port, allowing about 1-watt of output power.
Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems, often marked with ludicrous power output claims, are small plastic boxes with dismal sound quality. Some of the slightly better computer speakers have equalization features such as bass and treble controls, improving their sound quality somewhat.
The inernal ampifiers require an external power source, known as a 'wall-wart'. More sophisticated computer speakers may have a 'subwoofer' unit, to enhance bass output, and these units usualy include the power amplifiers both for the bass speaker, and the small 'satellite' speakers.
Some computer displays have rather basic speakers built-in.
