MOVING COIL DRIVE UNIT AND AUDIO DRIVERS INCORPORATING THE SAME

摘要

A moving coil drive unit for exciting a resonant member into a vibrational state is disclosed. The moving coil drive unit comprises a magnet assembly and a coil assembly comprising a voice coil arranged concentrically with the magnet assembly and configured such that the voice coil is moveable axially relative to the magnet assembly in use. The magnet assembly comprises a permanent magnet and one or more pole pieces. The magnet assembly is configured to provide an annular magnetic gap, the voice coil being suspended therein. The pole piece is configured to have a laminated structure comprising at least two spaced layers. The pole piece may include at least three spaced layers, preferably at least four layers. One or more of the layers of the pole piece may be shaped, in at least an region thereof surrounding the magnetic gap, so as to generally follow and guide the magnetic field lines emanating from the permanent magnet. A distributed mode vibrating panel loudspeaker comprising the moving coil drive unit arranged as an exciter is also disclosed. The distributed mode vibrating panel loudspeaker comprises a resonant member to be vibrationally excited in use and a backing frame supporting the resonant member. The exciter is supported by the backing frame and the coil assembly is mechanically coupled to the resonant member to be vibrationally excited in use.