Receivers, amplifiers and speakers are all examples of stereo system components. Systems may also use CD players, AM/FM radio tuners, and either stereo cabling or components that allow for wireless signal transmissions to connect various components.
The heart of a stereo system is the receiver. Stereo receivers combine the features of radio tuners and amplifiers. Receivers are used to select the signal source, adjust volume and alter sound quality. Speakers are powered by electrical signals that have been enhanced by an amplifier and transmitted through audio cables. Electrical current flows through the speaker's coils, activating an electromagnet that moves the speaker's diaphragm to create sound.