Mildly OT as the wiring is for car audio, but I suspect I might get a bit
more sense here.

I'm going to be fitting some speakers, a subwoofer and an amplifier to my
car. The subwoofer is there due to the near impossibility of getting deep
bass out of the ordinary speaker fittings present, not to test the fixings
of the interior trim.

The recieved wisdom is to run all your phono cables carrying audio signals
down one side of the car, and on the other side of the car to run your power
cable. This is supposed to stop crosstalk to the line level cabling from the
power wires. A fairly typical car amp can draw 25-50A, so it's a pretty
beefy cable, carrying a lot of power. However, all your wires eventually
have to meet at the amplifier, and as mine's going to be under a seat or
inside the quarter panel rather than in the boot, that's going to mean very
long wires going around the edge of the carpet. Obviously speaker cabling
has to be run from the amplifier to the speakers - could this also be
influenced by crosstalk?

Has anyone got any idea if there's likely to be an actual problem if I route
all my wires down the same side of the car? I'm going to be making my own
phono cables, so any recommendation of types of cable that are particularly
well screened would be helpful.