I was using nine 18 gauge wires on one leg but by just slightly repositioning the speakers (0,5mm rotation), using the 10th improved the sound. I did have to take ~3/8" off of one turn on a 600 watt crossover inductor. That required burning a new slot on the plastic inductor form, to hold the wire in place.
I exchanged the 10th wire on each leg from regular wire with a 6n pure 18 gauge wire. I mean my system, playing YT Premium, sounds unbelievable, clearly beating anything I had auditioned playing redbook/high rez and shows and homes, until the 6n wires were installed. Now it is un-freakingly unbelievable.
The changes are at extremely low level musical signal levels, spacial Qs, harmonic structure etc etc. It should have not surprised me though, since 6" length of 6n wire made a difference in my hugely upgraded dac.
The obvious limiting factor is the recording. Another question. Do I want to spend a grand on all 6n pure speaker wire?
I will wait a while and time will tell.
steve