A compact, sub-bass loudspeaker designed to provide high SPL extended bass to Adamson SpekTrix line array cabinets, the SpekTrix Sub is the first Adamson enclosure to introduce Convertible Cardioid Technology, and is a single-sided box that can be arrayed conventionally (all facing the same way) or can be arrayed in back-to-front pairs for true cardioid performance. The SpekTrix Sub is equipped with two powerful AW18 Kevlar bass drivers in a tuned, vented enclosure. The cabinet is fully braced to minimize LF resonance and maximize efficiency. Four sets of captured, precision-machined aluminum rigging hardware are spring-loaded and retract into the cabinet body when not in use; and four NL8 connectors (two front, two back) enable easy cable loop-thru regardless of the sub's orientation.