I have a Mackie Sound Board coming in as my mic/aux in so I can stream to Facebook a Sunday church service. The line in is a fully mixed service including mics and music. I also have a line out to the board so that music and videos can be played in the sanctuary. The problem I am having is that the mic sound in is looping back to the sound board through the line out and sounds terrible in the building. It distorts the sound and ruins the mix that was set on the board. The Facebook stream sounds fine. How do I prevent mic/aux from going back to the sound board before Easter service tomorrow?