BEHRINGER Black (VQ1800D) Professional 500-Watt powered subwoofer for PA applications Powerful 18'' long-excursion transducer with high temperature voice coil provides incredibly accurate and pulse-pounding bass Precise reproduction of ultra-low frequencies for "bulletproof" punch and impact State-of-the-art 500-Watt Class-D amplifier with comprehensive over-excursion, thermal and clip limit protection Built-in active stereo crossover provides high-pass filtered outputs for full-range loudspeakers