 This cone, dome or other radiator is mounted at its outer edge by a flexible surround to a rigid frame which supports a permanent magnet in close proximity to the voice coil.For the sake of efficiency the relatively lightweight voice coil and cone are the moving parts of the driver, whereas the much heavier magnet remains stationary.Other typical components are a spider or damper, used as the rear suspension element, simple terminals or binding posts to connect the audio signal, and possibly a compliant gasket to seal the joint between the chassis and enclosure.