Features Includes: (2) JBL PRX718XLF Subs, (2) USA Power Plug, Manual 18"Differential Drive® low-frequency driver for low-distortion and higher SPL Efficient Class-D amplifier technology DSP Input limiter circuit, crossover, dynamic limiting, component optimization, selectable system EQ Integrated stereo pass-thru, with selectable HP filter, and polarity reverse Description Product Description The PRX718XLF extended low frequency subwoofer was designed and engineered to provide sub bass frequencies with accuracy and power. Used as a single sub in a sub/sat system or in multiples as part of a scalable, large format sound reinforcement system, the PRX718XLF performs with exceptional efficiency and control. The subs are stackable and light-weight ensuring quick set-ups and tear-downs. And due to their rugged construction are perfect for AV rental inventories. With a pole receptacle (that accepts a SS4-BK or SS4-BK24) on the top panel and integrated stereo pass-thru this is the most powerful low-frequency complement to the PRX full-range systems. The addition of a polarity reverse option further enables system optimization. The PRX718XLF is a high performance self-powered subwoofer system. The PRX718XLF is comprised of a powerful 2278G Differential Drive® dual voice-coil and magnetic gap, woofer driven by a 1500 Watt Class-D power amplifier. Sophisticated DSP is at the core of a fully featured input section, providing user selectable cross-over functionality, polarity optimization, protection, dynamic limiting and discrete component optimization.