Abstract: A driving member for a diaphragm in acoustic devices includes a body with opposite recesses into which driving rods are inserted. One end of the driving rods is attached to pressure rods which directly influence the diaphragm and the other end of the driving rods makes contact with the bottom of the recesses.

Abstract: The invention relates to a special embodiment of a plate which is to be able to transmit movement and compressive force as well as possess soft-magnetic properties with low losses and low reluctance. The latter requirement means, inter alia, that the plate, upon loading, will be subjected to a relatively great elastic deformation with an ensuing reduced ability to transmit movement and compressive force. By perforating the plate with a number of evenly distributed holes provided with pellets of a stiff resistant material with an axial length at least as great as the thickness of the plate, movement and compressive force may be transmitted from a compressive force-generating element via the plate to a compressive force-absorbing element without the plate being elastically deformed.