BEHRINGER EUROLIVE PROFESSIONAL B1800X PRO High-performance 1,800-Watt subwoofer for PA applications Extremely powerful 18'' long-excursion driver provides incredibly deep bass and acoustic power Extremely high sound pressure level (100 dB half space 1 W @ 1 m) 40 Hz  300 Hz frequency range (-10 dB), impedance 8 Ohms Precise reproduction of ultra-low frequencies with a clear, powerful punch