The Rane AC 23S active crossover can be configured as stereo 2 or 3-way, or mono 4 or 5-way. It employs 4th-order Linkwitz-Riley filter alignments to minimize phase difficulties in the critical crossover region. The AC 23S features XLR connectors with active balanced inputs and outputs. Simply put, a Linkwitz-Riley alignment is two cascaded 2nd order Butterworth filters exhibiting identical phase characteristics on their low-pass and high-pass outputs. This characteristic guarantees in-phase outputs at all frequencies. In-phase outputs are mandatory for proper acoustic summing of common signals from adjacent drivers in the crossover region. An added benefit of this topology is steep 24 dB per octave rolloff slopes. A slope of this magnitude guarantees drivers designed to produce a specific range of frequencies, and no more, will not be driven past their limits, thereby minimizing distortion and driver fatigue. To further guarantee the transparent operation of the AC 23S, adjustable delay circuits appear on the low & mid outputs of each channel to compensate for any physical misalignment of the drivers. Time correction ensures the mechanical phase alignment of adjacent drivers will be acoustically correct, thus maintaining the integrity of the electrical phase alignment of the crossover’s filters. In 2 or 3-way stereo mode, the low outputs may be mono'ed by moving an internal jumper. Constant directivity (CD) horn equalization is possible with an internal modification.