Abstract: A pole-mountable electronic chassis for mounting on an equipment support pole, including at least one enclosure for electronic circuitry and at least one passage completely through the enclosure sized, shaped, and arranged for receiving the pole. A passage web surrounds the passage and may optionally provide thermal conductivity or circuit support functions. A coupling is provided for fixing the enclosure in place. The coupling may be a low-profile coupling. The enclosure may be sized and shaped to also fit in industry-standard electronics racks.

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.