The 7050B subwoofer has balanced XLR IN/OUT connector pairs for five main channels and a dedicated LFE input connector for the LFE channel. Connect the signal cables from your source to the female XLR "IN" connectors on the lower connector row. Next connect XLR cables from the corresponding "OUT" male XLR connectors on the upper row to the input connectors of each 8020C monitor.
Turn the volume control knob on all 8020C’s monitors fully clockwise and switch the "Bass Roll-off" dip switch (switch 2) on all 8020C’s to "ON". This switch actuates an 85 Hz high-pass filter on the 8020C’s matching them to the main channel low-pass filter of the 7050B.
Alternatively you can connect to the 7050B a stereo pair of 8020C monitors by routing the signal cables from the source to the input connectors of the main monitors and an another pair of cables from the main monitors' output connectors to the "IN" connectors on the 7050B. In this configuration the volume controls on the main monitors affect the playback level of the 7050B too. The "Bass Roll-off" switch on the main monitors must also be switched to "ON" (switch 2).