MACKIE SA 1521Z When incredible accuracy and extreme output are a must, Mackie`s flagship SAz Series represent the finest active loudspeaker systems on the market. These four newly developed "Super Active" loudspeakers improve upon Mackie`s award-winning Active designs of the past with maximized power, re-calibrated electronics, high-definition neodymium drivers, and extensive acoustic design and tuning by the world-renowned Eastern Acoustic Works (EAW) engineering team. Detailed information on these speakers is available at http://www.mackie.com Features -> * Bi-Amplified; with 400W RMS low frequency and 100W RMS high frequency amplifiers * Electronic crossover filters, time correction, phase alignment, and thermal system protection * 44mm (1.75") neodymium compression driver * 381mm (15") LF long-throw woofer with high-temperature voice coil * 133dB SPL @ 1kHz/1 meter * Frequency Response: 44Hz to 20kHz