How does a speaker work?
An electric signal reproduced by an amplifier passes through the speaker wire in the form of an analog wave. This wave varies in terms of its frequency and its power, depending on the frequency being reproduced and the volume you have chosen. This signal enters the speaker via the binding posts and through the wiring inside the cabinet is sent to the voice coil. The signal travels through the voice coil, which is in close proximity to the magnet. As the signal's amplitude and frequency change, the force on the voice coil undulates back and forth, in reaction to the magnet. The voice coil rapidly vibrates along the axis of the magnet structure, thereby vibrating the cone. As the cone vibrates, the air immediately around it is pressurized and these pressurized air molecules translate into the sounds we hear.