The Mackie SRM450 Powered Monitor is a great PA speaker that gives bands studio-quality sound onstage. It's a 2-way, biamplified, optimized active system that needs no external power amp. Powered by FR series 300W (for lows) and 100W (for highs) amps; with a Linkwitz-Riley electronic crossover; a 300mm (12") long-throw, low-frequency transducer; precision titanium compression driver; and a maximum dispersion horn. Uses Mackie's Servo Feedback Controlled Woofer technology. 51 lbs.