Although the title makes you believe that this is only a 3 way active crossover is, this unit more. Thus, each channel features a stunning 5-band parametric equalizer which a selectable bandpass or shelf method works, different types of crossovers and expanded tone control networks, subsonic and ultrasonic filters. You can also use any output limiter so that the connected power amplifiers do not go fast clip. Currently I use this crossover for the simulation of 12 dB / oct filters Butterwoth 2 way or 3 way speaker systems. So you can relatively quickly the best passive filter will determine. Also for existing sets this crossover fine example to all frequencies below 38 Hz steeply to filter. This leaves more amplifier power on for the audible range of speaker systems and seems the amplifier more power in the house. Also this crossover may be used with 2 heavy amplifiers, 4 sub-bass cabinets and 4 tops in.