The SAC 22 from Rane is a 2-way, stereo crossover featuring state-variable 4th-order Linkwitz-Riley filter alignments to minimize phase difficulties in the critical crossover region. The advantage of using the Linkwitz-Riley crossover is that it exhibits identical phase characteristics on its low-pass and high-pass outputs. This characteristic guarantees in-phase outputs at all frequencies.
The steep 24dB per octave roll-off slopes of the filters protect speaker drivers designed to produce a specific range of frequencies, by ensuring that they will not be driven past their limits, minimizing distortion and driver fatigue. The SAC 22 utilizes a single thirty-one position, detented potentiometer to select the low/high frequency point. This is a distinct advantage over continuously variable designs using ganged potentiometers which can yield large variations in channel-to-channel matching.
The Mono Sub output provides a separate mono sum of the left and right low outputs with a 100Hz switchable low pass filter. The Subwoofer Output may be used along with the left and right low outputs. The input level control allows for decreasing the overall sensitivity of the entire sound system, including the mono subwoofer if one is used. The low controls allow compensation for sensitivity variations in amplifiers and drivers.