Topp Pro KS HD18A is an active powered DSP-processed subwoofer for all type of PA application. The high power 2000 Watt provide the ultimate power to SPL ratio for very satisfying high SPL application. The built-in DSP analyze and regulate incoming signal to ensure the optimum audio performance to be achieved. On top of the technical DSP setting, the KS HD18A also come with stackable situational DSP presets such as Normal, Extended LF & Boost. There is other stackable DSP presets such as the Subwoofer Crossover Point and Polarity Control. All these presets are easily configurable through the switches at the rear of the subwoofer.