An 18” bass reflex subwoofer – is packed full of low end. Unrivaled power, SPL of up to 132 dB and thumping bass (all the way to 38 Hz) make this powered sub the ideal add-on to mid/high units from the LINEAR 3 family when you need just a little more loudness and low end. LINEAR SUB 1800 A can also be used in combination with mid/high units from the LINEAR 5 family, or as a bass extension to the ELEMENTS BIG BASE system. 1200 watts, 1x 18" Speaker. 132 dB Max SPL Peak @ 10% THD (halfspace). Ideal add-on to mid/high units from the LINEAR 3 family, Rugged wood enclosure , Adjustable X-over frequency. Integrated HK Audio MultiGrips