What is it? A sub-bass enclosure housing two 18” drivers and incorporating Nexo’s Ray Sub technology. DetailsOffering low-frequency extension down to 31Hz at a sensitivity of 107db SPL, the RS18 is designed for both touring and installation applications. It features Nexo’s (patent pending) Ray Sub technology said to optimise positioning and phase relationships of radiating surfaces in vented enclosures, allowing acoustic distances from rear to front sections to always increase as frequency decreases. Consequently, rear and front sections are said to sum efficiently over the subwoofer’s entire bandwidth, allowing for an average of 5db gain from the rear section in the forward direction and cancelling in the rear direction.Ray Sub allows the same cabinet to be configured for any polar pattern - omni-directional as a standard direct-radiating subwoofer (when speakers are facing the audience), or highly directional when the cabinet is rotated sideways or upwards. With arrays, Ray Sub subwoofers can be set back to back, front to front - or alternately - and in vertical columns (when column length is sufficient), to be beam-steered upwards or downwards. Suitable amplifiers for use with the RS18 would deliver 3.5kW-8kW into 4 ohms or 17.5kW-4kW into 8 ohms (x2 channels). The enclosure is manufactured from birch ply and measures 520mm (W) x 1238mm (H) x 732mm (D). Weight is 90kg.