The 1600W HD1801 18" Powered Subwoofer is the ideal companion to your HD Series full-range loudspeakers, creating an immensely powerful and truly high-definition PA system that you can actually transport from gig to gig. Class-D Fast Recovery amplification makes the HD1801 ultra-efficient, effortlessly delivering massive power to the 18" driver that's custom-designed to handle the job. Expertly tweaked tuning filters, internal crossovers and protection circuitry are designed by EAW for the ultimate in professional performance. Take your Mackie HD (or any other) full-range system to the next level with the Mackie HD1801 Powered Subwoofer.