Modular horn loudspeaker

Abstract

A modular horn loudspeaker principally intended for use on emergency vehicles consists of three coaxially aligned cup-shaped parts, a sound chamber, a cover fitted to the sound chamber and a housing. The first embodiment of the modular, compact horn loudspeaker is implemented with a single siren driver and includes a dome-shaped driver diaphragm integrally formed onto an interior surface of the sound chamber. The sound chamber is an acoustical boundary defining member having curved propagation paths or horn throat channels formed in relief on a cup-shaped exterior surface. The sound chamber is coaxially aligned with and received in a tightly fitted cup-shaped cover member to define a plurality of curved horn throats of expanding rectangular cross sectional dimension directing the sound waves rearwardly around the diaphragm periphery and toward a housing rear wall. A magnet assembly is pressed into a heat sink formed in a larger and concentrically aligned cup-shaped housing having a closed rear wall for redirecting the sound wave forwardly, around the periphery of the cover. The horn mouth is defined by the circular peripheral wall of the external cup-shaped housing and the concentric and coaxially aligned sound chamber/cover assembly. A second, two driver embodiment of the modular loudspeaker places two drivers with magnet assemblies back-to-back, so that a first sound chamber's horn mouth exit apertures face a second sound chamber's horn mouth exit apertures. The resulting assembly yields eight paths from two sound chambers which blend into one coherent sound source, when placed in a housing adapted to accommodate two drivers. The back-to-back drivers are inserted in a larger bowl shaped back cover or housing having a first open end, a substantially frustoconical sidewall and a closed back end.