I've read here that Signal Cable (Frank) will custom make a subwoofer interconnect for you if you ask, i.e. add more than one wire per run. If you study what one of the higher end cable manufacturers says about the difference between the three subwoofer interconnects they sell you'll find that their least expensive cable has "one wire per run", the better cable has "two wires per run", and their best cable has "three wires per run".
The nice thing about dealing with Frank is if what you're asking him to do won't improve your system, he's the first one to suggest you save your money.
