I used my training from a previous EAA electrical workshop to get this nasty job completed. I say nasty because it took a lot of experimenting to determine the final location of the headphone ear and mic jacks for my setup. Using Bose X headsets with their own power supply, I didn't want that power supply laying along my leg. As you can see in picture 1, I will use some strategic Velcro to keep it attached vertically to the forward side of the F604 spar bulkhead. Keeps the controls forward of spar, nicely tucked to the side with easy access. Used a length of 1" angle and riveted it in place. Working on the jacks in the future is easy by a 1 inch hole in the subpanel, closed off with a rubber grommet. The jacks can be worked back through the hole and will drop down nicely for soldering or whatever might happen in the future. By then, I'll probably forget about the access holes and curse while I struggle with short leads.
That is a perfect location. Out of the way, No wires aft of spar. Nice place for Bose control
Soldering 8 wires plus one wire extension fwd of sub panel. Aaarg.
Fwd of subpanel shows grommet and jack wires. Need to finish wrapping wire now.
