Abstract: The invention is a shaped base plate assembly onto which one or more separate units may be detachably mounted. One common latch plate, bolted to the base plate, fixes all the separate units in place in fixed relation to each other and to the base plate. The invention may be employed to mount four separate transformers to a common base plate. Each transformer is fitted with appendages such as four cylindrical legs, each leg being shaped with a circular undercut of reduced cross-section adjacent the free end of the leg. The base plate is formed with sets of keyhole-shape or teardrop-shape holes, with each set of holes located to accommodate the legs of a given transformer. When all four transformers have been inserted and then slid into the latched position, a latch plate is fastened by one latch screw to the base plate. The latch plate is of a shape and size to abut against at least one leg of each transformer and to bias the undercut section of each transformer leg snugly against an edge of a base plate hole.

Abstract: A loudspeaker having precise imaging, neutrality of frequency response, and controlled mid-range and tweeter dispersion. The loudspeaker incorporates an open cell, reticulated polyurethane cartridge for placement of a supertweeter mounted in the loudspeaker at an angle of 45.degree. from other speaker axes. The housing therefore may be positioned so as to adjust the high frequency acoustic radiation to the right or the left of the loudspeaker frontal axis, thus making a mirror image pair of the loudspeakers possible. In addition, angled corner posts are arranged at the front corners of the loudspeaker in order to reflect back into the loudspeaker mid-range and high frequency sounds that strike the posts.