The Mackie Thump 18S is a powerful active subwoofer for live music venues. With a powerful 1200W Class-D power amplifier and a custom 18 high-output woofer the Thump 18S delivers rich deep bass with outstanding definition. Combined with a selection of stereo output options you can configure your PA system to suit a wide variety of venues and situations in seconds. You can rely on your subwoofer every single day. With Mackies Built-Like-A-Tank construction consisting of a solid all-wood cabinet the Thump 18S has been built to withstand the demanding nature of life on the road. Plus integrated protection circuitry ensures that your system runs safely and smoothly night after night.