The LC8i is an eight channel (4 stereo input) line converter that is very versatile in routing and summing the signals from your factory head unit.
***Special Note about summing***
Summing mode can sum all channels to the MAIN output. It does NOT sum all channels to ALL outputs.
When summing mode is engaged on a given channel, it does NOT cut off that signal to that specific channel output.
Below are some diagrams of typical scenarios of how you can setup your LC8i.
Click on the image for a larger version
AutoMode: When there is signal present on the channel 3 input but no signal present at the channel 4 input, AutoMode automatically takes the channel 3 input and routes that signal to the channel 4 output. If you were to connect speaker cables to the channel 4 input, AutoMode would automatically disengage and pass the channel 4 input signal to the channel 4 output.
You can find more information about the LC8i on the product page here