Thanks for the reply shock. Keeping the mic channel active regardless of screen configuration is exactly what I want to do and that is the part I can't figure out. As for adding more mics, that really isn't an option for me for two reasons: one, my card only supports 4 channels of audio and i have 16 cameras and second, i won't be able to run wires because when we renovated, we added low gauge metal on the roof (we've had breakin's before) and I ran the existing cables before we put the metal in place and running additional cables will be very difficult.
I'm not sure if this will help but I did run an extra bnc where i have the mic thinking if I ever wanted to add a quad processor in the future. Thanks