Abstract: An electromagnetic transducer in which a first set of magnetic poles confronts but is offset from a second set of magnetic poles across a space containing a diaphragm parallel to the planes containing the faces of the sets of poles. Conductors affixed to the diaphragm traverse the zones of flux between the two sets of poles and the current is so directed in the conductors that forces on them sum to move the diaphragm in the directions perpendicular to the planes of the pole faces. The magnetic poles may consist of magnetised ferrite material between which poles in each set ferrite material is absent. The ferrite material may be provided in sheets of plastic bonded ferrite material. A second transducer unit may be combined with the first to provide two or more diaphragms operating in cascade. Coupling between the diaphragm and the wave propagating environment or between the two diaphragms is effected through the spaces between the poles in the respective sets.