Abstract: A single folded, expanding horn loudspeaker reproduces low frequency audible sound at high power output levels. A compact enclosure houses a plurality of identical transducers, characterized by small vibrational surface areas. The throats for each transducer into the horn are acoustically differentially spaced from the mouth of the horn. Transducer drive circuitry adjusts a drive signal for the transducers to compensate for the different impedance and propagation time to the horn mouth at each throat.

Abstract: A loudspeaker assembly includes a housing defining a bass-reflex enclosure. The housing has a trapezoidal cross-sectional shape in a vertical section running from front to back of the housing. A conventional low frequency cone woofer is mounted in an aperture in the front face of the enclosure. An elongated port is defined in part by one of the sides of the housing and its top and bottom sides. The elongated port has varying vertical and horizontal cross sectional dimensions to conform to the sides of the enclosure while maintaining a constant cross sectional area. A planar is mounted to the front face of the enclosure over a tuned rear chamber.