The 18-inch, Eminence, 650-watt RMS, 27Hz subwoofer speaker, coupled with the B18S's finely tuned box, results in lows that move your pants. In live applications, this massive sub drops the kick drum and bass guitar into the abyss. The professional D.J.'s beats and bass lines have a home in the thundering lows produced by the B18S. It supplements the punch of B215H's for clubs who feature a D.J. With PS21015H's, the full-range of the E.Q. spectrum is complete, and separation of the lows and low-mids is achieved. Sports a half-inch, heavy-gauge grill and ball-bearing removable casters.