The 234xs from dbx is a dual channel, stereo 2/3-way or mono 4-way crossover. A crossover is essential for efficient PA operation because it filters the full band input signal into specific frequencies that match a speaker's optimum frequency-reproduction range. This leaves the amplifier free to use its full power on the usable signal, eliminating distortion and delivering clear sound. The unit features Linkwitz-Riley 24dB per octave filters, independent output gain controls for level matching, output phase inversion, 40Hz low cut filter, and optional mono summing of the low frequency (subwoofer) output. Quality components and meticulous attention to detail offers exceptional sound and rugged reliability, while exuding great precision from the solid "click" controls to the high quality 1/4" TRS inputs and outputs. TRS differentially balanced ins and outs Mode switches for mono 4-way or stereo 2-way/3-way operation Low frequency summed (subwoofer) output x10 range switch on both channels 40Hz high pass (low cut) filter both channels Phase reverse switch on all outputs Individual level controls on all band outputs 24dB per octave Linkwitz-Riley filters (the professional standard) Stereo/Mono status LEDs indicate the selected mode CSA NRTL/C approved CE compliant