The 223s is a dual channel crossover 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. Everything in the design exudes great precision from the solid click controls to the high quality 1/4" TRS inputs and outputs. The 223s uses precision filters to separate the audio signal and direct the correct frequencies to your loudspeaker drivers. By directing only the specific frequency bands to each speaker driver the 223s leaves amplifiers free to use their full power on the usable signal eliminating distortion and giving your PA system a cleaner and better sound. The 223s crossover provides great performance, ultra low-noise, rugged reliability and four decades of dbx knowledge and expertise in building the world's finest processors.