The Mackie SRM1850 18" Powered Subwoofer is designed to extend the low-frequencies of sound systems and is well suited for various sound reinforcement applications including portable DJ's, live stage, houses of worship, theater, rehearsals, and more. The integrated Class-D amplifier drives 1600W of power to the 18" woofer, which provides a frequency response of 40 to 120 Hz with a max SPL of 132 dB. The tour-grade poplar plywood enclosure is front ported and internally braced to deliver maximum low-frequency extension and punch.