Abstract: A sound imaging system preferably including two enclosures each comprising a truncated conical base unit and a truncated conical upper unit supported above and spaced apart from of the base unit, and containing a bass driver and composite midrange and high frequency drivers. The bass driver is oriented horizontally at the top of the base unit, and the sound energy produced therefrom is reflected by a conically shaped acoustic lens or defector depending from within the interior of the upper unit directly above the bass driver, such that the sound energy is reflected downwardly along and between the spaced apart truncated conical walls of the upper unit and base unit and emanates radially therefrom in all directions. The composite midrange and high frequency drivers are supported at the top of the upper unit on a crown structure having a plurality of vertical legs defining a platform oriented approximately 20.degree. relative to horizontal.

Abstract: A ridge cap type roof ventilator comprising a plurality of sections aligned longitudinally with one another and hingedly interconnected along their confronting ends such that the plurality of sections may be folded or pivoted into parallel abutting contact. Once folded, several roof ventilators may be stacked with their vent parts in an overlapping, interfitted pattern to provide a stable column or stack having a minimal volume to conserve the space required to store or ship a predetermined number of the roof ventilators. The sections may be unfolded for positioning and installation on the ridge of the roof.