The Plus Audio MPS18A (model code MPS18BA) is a powered 18-inch subwoofer for live sound, DJs, churches, clubs and hire companies who need deep, controlled bass. A single 18-inch driver is driven by a 1000 W RMS Class D amplifier, producing up to 135 dB SPL with a frequency response of 40 - 120 Hz. The cabinet is birch plywood with a polyurea coating for resistance to corrosion, wear and moisture, plus rubberised skids to stop it walking on stage and a 35 mm threaded pole socket for mounting a top speaker. Two combo XLR inputs and two XLR outputs allow linking to tops or further subs. A 2.4-inch colour screen gives access to master volume, level metering, a low-pass filter (off or 40 - 100 Hz), polarity, delay of 0 - 100 m and setup modes including Normal, Cardioid Rear and Cardioid Front for directional bass arrays. The sub can also be controlled over Bluetooth from Plus Audio's Android and iOS app. Power consumption is 500 W; it measures 605 x 695 x 660 mm (H x W x D) and weighs 55 kg.