Hi jai:
For the compsite, they used shield coaxial cable, so the core is the core of cable, shield is the shield.
We suppose to used this kind of cable, but it is too big and will be very difficult to hide somewhere, instead I choose the flat shield cables.
In the flat shield cables, each one has a core and a shield, so we can just joint 3 shields into one.
Please correct me if I am wrong.
BTW: Chris: can I ask, Do we have to go the ground?