Spherical membrane omnidirectional loudspeaker using a magnetostrictive bimetallic strip

Omnidirectional loudspeaker comprising a spherical membrane which includes spirals formed by a strip made of a magnetostrictive material, said spirals being wound onto an elastic support in the shape of a sphere, thus forming said spherical membrane, the strip having two opposing faces, one of said faces being directed towards the inside of the sphere and the other towards the outside of said sphere, and two extremities situated in two diametrically opposing zones of the sphere so as to be connected to an electric control device supplying a signal corresponding to sound waves to be reproduced, and a device to continuously polarize the membrane, wherein at least one of the faces of the strip is at least partly coated with a thin coating made of a rigid material, the strip having over its entire length transversal undulations, each undulation having on the face of the strip directed towards the inside of the sphere one concave zone and one convex zone, and on the face of the strip directed towards the outside of the sphere one concave zone and one convex zone, the rigid coating being localized at least partly on the face of the strip directed towards the outside of the sphere opposite the convex zones.