Computer speakers or multimedia speakers , are speakers external to a computer , that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.5 mm (approximately 1/8 inch) stereo phone connector often color-coded lime green (following 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 500 miliamps provided by the USB port , allowing about 2.5 watts of computer power.
Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small plastic , and have mediocre sound quality. Some computer speakers have equalization features such as bass and treble controls.
The internal amplifiers require an external power source , usually an AC adapter. More sophisticated computer speakers can have a subwoofer unit , to enhance bass speaker , and the small satellite speakers.