Craving some extra oomph for your PA system? You need a subwoofer. The Mackie Thump18Sv4 shakes the floorboards with massive bass that gets people on their feet. Connect loudspeakers. Dial in the perfect low end. Feel the difference of a professional subwoofer that brings music to life with complex basslines and punchy kicks. The Thump18Sv4 integrates perfectly with Thump loudspeakers, with voicing modes that automatically tailor the sound to match the size of your speakers. You can also set the crossover manually for more control over your sound. Built-in carry handles make the Thump18Sv4 portable enough to add to your touring rig or gigging setup.