Abstract: AMENDMENT TO THE ABSTRACT The invention relates to an enclosure for diffusing sound by reverberation comprising:—a loudspeaker comprising a fixed frame, a cylindrical support and a membrane connected to an upper bearing surface of the frame; and—a wave guide mounted on the upper bearing surface, the wave guide being substantially in the form of a truncated pyramid with a long wall forming a front face, a short wall and lateral uprights; the wave guide comprising at least one acoustic wall fastened to the lateral uprights, the acoustic wall extending tangentially relative to the generatrix line of the cylindrical support closest to the front face.

Abstract: The invention relates to a broadband electrodynamic transducer for headphones, said transducer comprising: —a magnetic motor designed to generate a magnetic field; —a coil that is disposed in the air gap of the magnetic motor and can move translationally under the effect of the magnetic field; and —a membrane that is connected to the coil in such a way as to convert the translational movement of the coil into an acoustic wave; —the transducer comprising a self-supporting coil that is glued to the membrane, the membrane having a Young's modulus of more than 40 GPa.

Abstract: A circular acoustic membrane having an upper surface and an opposite lower surface, said membrane being intended to be coupled, at the lower surface thereof, to a mobile winding via a support. The membrane has an annular fold concentrically delimiting, in the membrane, a circular central portion and an annular peripheral portion. In addition, the central portion has a concavity turned towards the upper surface and the internal edge of the fold is carried by the lower surface and comprises an attachment surface intended for the coupling of said support of the coil.

Abstract: The invention relates to a broadband electrodynamic transducer for headphones, said transducer comprising:—a magnetic motor designed to generate a magnetic field;—a coil that is disposed in the air gap of the magnetic motor and can move translationally under the effect of the magnetic field; and—a membrane that is connected to the coil in such a way as to convert the translational movement of the coil into an acoustic wave;—the transducer comprising a self-supporting coil that is glued to the membrane, the membrane having a Young's modulus of more than 40 GPa.

Abstract: The invention relates to an acoustic impedance matching device arranged so as to be mounted behind a loudspeaker. Said device comprises a chamber at least partially filled with an absorbent material. Said device is characterized in that the cross-section of the chamber increases with the distance from the loudspeaker, and the density of the absorbent material increases with the distance from the loudspeaker.

Abstract: The invention relates to a suspension device for a loudspeaker, comprising an annular outer edge that is able to fasten the suspension device to a frame, an annular inner edge that is able to fasten the suspension device to a membrane, a suspension hoop that extends annularly between the edges, said suspension hoop being able to absorb movement stresses produced at the inner edge by means of a deformation that thus forms a resonance mode, the suspension hoop comprising at least one annular protuberance that is positioned so as to minimize the at least one resonance mode of the suspension hoop, the mass of the at least one annular protuberance being between 150% and 400% the mass of a part of the suspension hoop on which the at least one annular protuberance is positioned.

Abstract: The invention relates to an acoustic impedance matching device arranged so as to be mounted behind a loudspeaker. Said device comprises a chamber at least partially filled with an absorbent material. Said device is characterized in that the cross-section of the chamber increases with the distance from the loudspeaker, and the density of the absorbent material increases with the distance from the loudspeaker.

Abstract: The invention relates to a speaker enclosure comprising at least two channels, wherein a first and second channel are respectively dedicated to separate and adjacent first and second frequency bands, each of said channels including a filtering stage supplied by the control signal and a speaker unit, wherein said speaker enclosure is characterized in that said channels also include means for simultaneously: disconnecting the first channel from the control signal; and modifying the filtering stage of the second channel so as to modify the frequency response thereof.

Abstract: The invention relates to a loudspeaker membrane having a sandwich structure, having a central web separating two layers of material based on high-rigidity threads impregnated with a polymer resin, characterized in that the central web is formed from a layer of material based on oriented natural fibers that are impregnated with a polymer resin.