sub

2400W Powered 18" Subwoofer with Built-in Stereo Crossover and Intelligent Limiter
  Behringer DR18SUB - 18" Powered Subwoofer

The DR18SUB pumps out 2,400 watts of Class D amplification from its 18-inch custom-engineered driver to fortify your portable or permanent-install PA system.

Behringer Eurolive B1800XP 3000W 18" Powered Subwoofer (B-1800XP / B 1800XP)

With subs as intelligent, high-performance, and lightweight as the Behringer Eurolive B1800XP, it's never been easier to add big bass and hard-hitting low end to your live rig. Gone are the days of pairing the right amp with the right speaker and tuning the crossover just so.