Sound reinforcement enclosure employing cone loudspeaker with annular central loading member and coaxially mounted compression driver

DETAILED DESCRIPTION A sound reinforcement enclosure is provided with at least one cone-type loudspeaker operating into a channel extending forwardly towards an outlet to free air.
At least one central member is inserted within the channel and on a common centerline whose rear surface is substantially parallel to the surface of the cone and whose sides, together with those of the channel, produce an annular region having a progressively increasing crosssectional area which couples the volume defined by the cone with the outlet to free air.
At least one coaxial opening in the central member is provided, extending from the volume defined by the shape of the cone to the outlet to free air, and of progressively increasing crosssection.
The resulting apparatus provides a marked improvement in dispersion, efficiency and projection while requiring an increase in enclosure depth which is only a fraction of that required by prior art methods.
By mounting the high-frequency compression driver to the rear of the loudspeaker magnet assembly such that its outlet aligns with the central opening in the latter, and by employing a horn flare which may pass through the center of the loudspeaker voice coil form, the high frequency driver and horn may be mounted coaxially with the loudspeaker, reducing enclosure size and improving intelligibility.
Both the mid-high information which radiates from the region of the loudspeaker cone immediately surrounding the voice coil and the high frequency output of the compression driver and its associated horn couple to the horn flare formed by the passage in the central member.
By mounting a second loudspeaker within the enclosure centered on a common longitudinal plane with the first, and by ducting its output to free air, the width of the enclosure can be halved relative to prior art enclosures with the same components.