I just bought events PS-6 monitors to use in my project studio. I have a tascam 414 portastudio which has RCA L and R MON OUT outputs on the back. To hook the monitors up I bought two RCA to XLR cables, which seem to be working. My question is, when I want to just listen through the headphones, I always have to unhook the monitors. I thought that it was possible to just bypass then so that the mix is only playing back through the headphones, but so far I've had no luck. Is this normal?