Command line jack application providing 2, 3, or 4-band, 4th order crossover filters. The filter type is continuously variable between Linkwitz-Riley (-6dB at the xover frequency) and Butterworth(-3 dB at the xover frequency). Outputs are exactly phase matched in the crossover regions.

The application supports up to 16 channels.

Configuration is by a text file using 'OSC' style syntax (similar to Ambdec and Jconvolver). Apart from the basic filter parameters, the following can be set: - Channel labels (used for naming Jack ports). - Frequency band names (used in output port names). - Optional output autoconnections. - For each channel: gain and delay (in ms). - For each frequency band: gain and delay.