Abstract: A modular housing system made up of wall panel units, roof panel units and floor panel units. Each unit is a framework made up of members which are preferably wooden or metal 2.times.4's or other readily available shape. The units are uniformly predrilled for connectors in such manner that they can be readily rotated into a variety of orientations and yet register with the connector holes in the adjacent unit.The system utilizes a novel removable connector also disclosed herein, an elongated headed pin having at its opposite a pair of parallel chordal slots adapted to receive both a serrated locking plate and a tapered wedge. The locking plate is disposed next to the wood and the wedge is tapped into locking position on the plate by motion parallel to the surface of the wood. It can not be unlocked by motion in the opposite direction, but can be removed simply by prying up on the end spaced away from the pin hole.

Abstract: A multiplicity of sound modules are mounted on a number of baffle plates which define an essentially continuous surface, e.g., a ceiling. Each sound module consists of a loudspeaker and a cavity-defining member which may be a thin-walled shell or a rectangular block of lightweight material, e.g., foamed polystyrene. The cavities are preferably spherical and of equal size, and the loudspeakers are preferably identical and electrically interconnected for simultaneous reproduction of a common input signal.The baffle plates are chosen to correlate with existing interior designs, and thus may be flat or curved, and may cooperatively or individually support one, two or several sound modules. When 2 by 2-foot acoustic tiles are employed, the invention may be thought of as embodied in like units each consisting of a factory assembly of at least one loudspeaker, the same number of cavity-defining members, and a baffle plate in the form of an acoustic tile, the latter not necessarily being of sound absorbent material.