Loudspeaker: is an apparatus in which electrical energy is converted into sound energy. Its sound output is audible over a large area. Current is passed through a small voice coil fitted to the apex of a conical paper diaphragm. The voice coil travels in an angular gap over the middle arm of an E shaped permanent magnet. The voice coil is held in position in the center of the gap by a flexible plate. When an alternating current passes through the coil the paper cone diaphragm vibrates at the same frequency and emits sound waves. Since the diaphragm is conical the sound waves emitted are much stronger than the sound waves produced before the microphone.