ACDelco GM Original Equipment Car Speakers turn electrical energy into mechanical energy to move air using a permanent magnet and an electromagnet, and are GM-recommended replacements for your vehicle's original components. The electromagnet is energized when the radio or amplifier (if equipped) delivers current to the voice coil on the speaker. The voice coil forms a north and south pole that causes the voice coil and speaker cone to move in relation to the permanent magnet. The current delivered to the car speaker is rapidly changing alternating current (A/C). This causes the speaker cone to move in two directions, producing sound. These original equipment car speakers have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.