I'm using a Tascam US-1800 which has monitor outs, L&R and 4 balanced outs (TRS). I have 1 pair of monitors (for now). As an experiment, I plugged my monitors into the balanced out's. I get sound out of 1&2 but not 3&4, which I am thinking is because 1&2 need to be used 1st, kind of a cascading...