The Thunder-KS4 I is a compact active subwoofer featuring a 2x18” cone drivers and a powerful 4x 2500W @ 4Ω audio amplifier module with built-in DSP. The audio power output connectors allow the Thunder subwoofers to drive a wide range of K-array passive loudspeakers. Compatible with midrange loudspeaker and other passive subwoofers, the self powered Thunder subwoofers with DSP are designed to be the core devices in K-array sound reinforcement systems.