Abstract: An apparatus and method for centering a voice coil in a loudspeaker having a vented pole piece. The voice coil centering is accomplished by means of a concentrically located voice coil suspension and an attached cylindrical mounting ring that can be set into a recess, or otherwise positively located on the pole piece. The pole piece is formed in such a way so as to precisely receive a suspension mounting ring and center the voice coil in the magnetic field gap with no further adjustments. This invention permits the use of a pole piece mounted voice coil suspension on a ventilated pole piece.

Abstract: A loudspeaker horn which provides constant coverage angles in both the horizontal and vertical planes and affords proper driver loading and a smooth impedance curve down to the lowest frequencies of operation. The throat entrance of the horn is round, to match the driver exit hole, and the throat section expands exponentially, with substantially straight and divergent top and bottom walls and curved side walls. The throat section joins to a transition section in which the side walls expand outward at a more rapid rate and a central vane is introduced top to bottom that both maintains an exponential flare rate and divides the transition section into two vertical slits. The length and width of the transition section are determined by the upper limits of the frequency range and the horizontal coverage angle. The transition section joins to the wave guide section which has a substantially planar side walls forming a conical expansion wave guide with side angle equal to the coverage angles of the horn.

Abstract: A loudspeaker having uniform horizontal sound dispersion characteristics in a design angle and minimal sound dispersion vertically comprises multiple sound energy sources forming an elongated line source of sound energy, and a waveguide having an elongated input portion coextensive with the elongated line source and substantially planar side walls defining an expanding cross-section from the input portion to an exit aperture, whereby sound dispersion in a direction parallel to the line source is minimized. The waveguide expands substantially only in a direction perpendicular to the line source, the rectangular input portion having substantially the same dimension as the exit aperture measured in the direction parallel to the line source.