This is a good question, I may make a youtube video explaining this on my channel (Audioczarnet).
What you need first is studio one professional so you can have access to the pipeline XT, you also need a audio interface with multiple inputs and outputs. (more than two)
so if you using outputs 1 and 2 for your speakers, lets use output 3 for example. You'd connect output 3 of your interface to the line input of your channel strip. Then connect output of the channel strip to input 3 on the interface. Then load pipeline XT mono on to a track in studio one. Select input and output 3 on pipeline plugin. Now sound will go out of the interface, through the channel strip and back into studio one.