The invention concerns a loudspeaker with a diaphragm which is electromagnetically induced to vibrate and is made of a central dome-shaped part and a conical part surrounding the latter, and a phase-correction device, consisting of a cone fixed in the housing with its base side matching the shape of the diaphragm and of two rings surrounding the cone concentrically, between which there are sound paths from the diaphragm into the sound outlet area. The object of the invention is to smooth out the transmission characteristic of the loudspeaker named initially and to enlarge the transmissible frequency band with simple means. The invention is characterised in that the ring surrounding the cone covers the boundary area between the dome and the cone of the diaphragm and on the side facing the diaphragm consists of two essentially conical surfaces, in that the axes of the sound paths between the cone and the neighboring ring and between the two rings are each aligned on a point on the loudspeaker axis, in that the sound paths become broader as the distance from the diaphragm increases, and in that the distances from the middle of the underside of the cone and from the middle of the surface of the rings facing the diaphragm to the sound paths are roughly the same.

The invention relates to a sound distributor with symmetry of revolution. The distributor comprises two sound reflecting cups, having a convex shape which is an exponential of surface revolution about a fictitious axis. The outer surfaces of these cups are arranged in tail to tail manner. The distributor has at least one sound source positioned facing a small opening of one of the cups. Around an opening in the bottom of the second cup, the distributor also has a trumpet-shaped reflector and a cone-shaped reflector for directing sound along the axis.

An electroacoustic motor for association with a horn comprising, in combination, a direct radiation speaker including a chassis, the speaker including a movable diaphragm, an acoustic wave transmitting means comprising an output orifice at the end thereof remote from said diaphragm, and passage means in the acoustic wave transmitting means communicating acoustic waves from the diaphragm to the output orifice. The acoustic wave transmitting means is a separate unit which is detachably secured to the speaker chassis by a fluid-tight connection. The acoustic wave transmitting means comprises a hollow truncated conical member of smaller diameter at the output orifice end thereof than at the end thereof contiguous the diaphragm. A phase adjustment element is positioned in the hollow interior of the truncated conical member, the phase adjustment element being in facing relation at one end thereof to the diaphragm and at the opposite end thereof to the output orifice of the truncated conical member.

A sound field equalizing apparatus for a speaker system which is capable of widening a region in which it is possible to effectively hear a sound field. The apparatus includes a sound field equalizing member disposed in a dispersing hole formed in a cabinet of a speaker for separating a sound dispersed from the speaker into a forwardly dispersed sound which is dispersed in a central direction and a laterally dispersing sound which is dispersed in a peripheral direction of the forwardly dispersing sound.

An improved compression driver has a phasing plug with air passages coupling the compression region of the loudspeaker to the throat of the loudspeaker. An auxiliary air passage combines with a plurality of inner primary passages, which may be of the annular, radial or saltshaker form, to couple variations in pressure from the region around the voice coil to the throat of the speaker.