The two long-excursion 15-inch transducers each feature a 3-inch high-temperature aluminium voice coil, a vented pole-piece for thermal management under sustained drive and a triple-roll surround for high excursion without compression. The internal enclosure is tuned through dual front-facing slot ports, and a precision-engineered bracing system isolates panel modes above 80 Hz. The cabinet presents a nominal 4-ohm load to the amplifier and supports a peak SPL of 138 dB at 1 m when driven from 2,000 W RMS per channel. Inputs are dual NL4 Speakon with linked feed for daisy-chained cabinets. Construction is 18 mm Baltic birch with a polyurethane finish and a perforated steel grille. The rigging hardware integrates with the Manchester Series main-cabinet hardware, allowing the MS215 to be flown at the top of a hybrid array or used as a ground-stacked sub beneath the main elements. Suitable for mid-format theatres, houses of worship, corporate AV, and as the LF foundation for the M10 and M12 mid-high cabinets. Designed and engineered in the U.K.