I'm currently using a Radial MC3 monitor switcher, fed from the monitor A output. The Radial unit has a sub out which feeds the sub. The Radial is only a passive unit, however, so I have no way to raise the sub level, which is what I need to do. I'm already using the monitor B output to feed headphones. So, my question is, how can I feed the sub from the DA7 where the volume level changes along withe the monitor A L/R level? The Record outs and the Master outs appear to be fixed level signals. I want the sub level to change along with the overall level of my monitors, as it should in order to evaluated mixes at different volumes. Am I missing something obvious here?