The DXS18 is an extremely powerful subwoofer equipped with a 1020 watt amplifier and 18" driver. The on-board DSP provides protection to the system and options for Xtended and Boost modes. Capable of an SPL of 136dB, delivered with exceptional clarity and accuracy. The Cardioid mode setting adds additional control of low frequencies for subwoofer arrays of two or more DXS18 speakers.