I don't understand what you mean by "wiring the power boxes i n parallel," you'll have to draw a diagram of what you are considering.
What I meant is that in a parallel circuit, voltage is the same across all components, so you wouldn't have any voltage drop. But again, I don't know if it's possible to implement that and at the same time have the audio wiring right. In any case I think I'm going to go unbalanced
I'll draw a complete schematic with values and report back.
Thanks a lot for your time and help