The QSC KW181 is an 18‑inch powered subwoofer designed to deliver deep, clean low‑frequency reinforcement for live sound, DJ, and installed audio systems. It uses a 1000‑watt Class‑D amplifier module paired with a front‑firing 18‑inch driver to produce powerful bass output, with peak levels reaching 135 dB and usable extension down to the mid‑30 Hz range. The birch plywood cabinet and heavy‑duty steel grille make it durable for touring, while built‑in casters and side handles simplify transport. DSP features such as DEEP mode, Intrinsic Correction, and GuardRail protection help extend low‑frequency performance and maintain clarity under load. Connections include dual XLR inputs and full‑range outputs, and the sub integrates easily with tops using its M20 threaded pole mount.