Abstract: An electro-acoustic transducer comprises a metal single-piece blade diaphragm having a very good heat conductivity and mechanical characteristics, the metal blade of which is resiliently suspended and supports the acoustical current wire fixed at the center of mass thereof to the active metal surface of the transducer, so that the acoustical current wire communicates to the blade the heat which is produced because of the acoustical current and added to that generated in the blade because of the deformation of the resilient suspension.

Abstract: There is disclosed a method for making horn loudspeakers, of the sectorial diffusion type, characterized by the transformation, in order to operate under predetermined sectorial diffusion conditions, of a horn loudspeaker, predisposed for circular diffusion, comprising a horn provided with opposite walls the distances whereof increase according to a given law, from the axis of the horn on which the electroacoustic transducer is located, the transformation being carried out by neutralizing the space included between the walls and about the compression chamber associated with the transducer, and in the directions in which the diffusion is not desired, by using a substantially fibrous material and effective to absorb or deaden the acoustic energy or power.