Used Mackie Active Sound Reinforcement Speaker SR1521z x2 The SR1521z is a high-efficiency, high output, hornloaded, 2-way, wide-dispersion, active sound reinforcement system. The SR1521z benefits from the integration of 500 watts of amplifier power, complete active control electronics, and precision transducer components. These elements together form a speaker system with unprecedented output, resolution, and clarity. The 1.75-inch neodymium high-frequency compression driver features a low-distortion optimized symmetric phase plug. The low frequencies are produced by a high-output 15-inch woofer featuring a 2.5-inch high-temperature voice coil. Connecting and setting up the SR1521z is a breeze. It accepts a line-level signal via a female XLR input jack. A male XLR Thru jack is provided for daisy-chaining the signal to additional SR1521z cabinets. Two built-in power amplifiers provide 100 watts rms for the high-frequency driver and 300 watts rms for the low-frequency driver