The invention discloses a moving coil type
loudspeaker, which comprises a vibrating
system and a
magnetic circuit system positioned below the vibrating
system, wherein the vibrating system comprises a vibrating film, a centering support
chip and a sound coil which are combined together from top to bottom, the vibrating film comprises a vibrating film body part with a folded ring, and a vibrating film reinforcement part combined at the center position below the vibrating film body part; the vibrating film reinforcement part consists of a first conductive material layer, the centering support
chip consists of a second conductive material layer, and the vibrating film reinforcement part and the centering support
chip are adhered by a conductive binder and are conducted; the
magnetic circuit system comprises a central
washer, a central
magnet and a magnetic conductive yoke which are combined together from top to bottom; the first conductive material layer and the second conductive material layer are used as movable polar plate, and the central
washer, the central
magnet and the magnetic conductive yoke are used as fixed polar plate, to form a
capacitance structure for detecting the vibration displacement of the moving coil type
loudspeaker. The vibrating displacement of the moving coil type
loudspeaker can be detected by utilizing the
capacitance structure provided by the invention.