Cable lengths

that should be a good closing statement for this thread

By coiling you create an extra inductance which is so small that it can be just neglected for audio freequencies.

On the other hand the difference in volume level tells that loads to an amplifier are different. To decrease this difference you should use thick 10AWG or even thicker speaker wires/cables.

I have posted this before but... Here is an interesting article on the subject. Click the link below.

Equal Length Speaker Cables - Are They Necessary?

Now I remember too, Bwihite about that article.
Moreover, It's almost impossible to find a HT system that uses equal speaker wire runs for mains, sub, center and surrounds(ABSURD!)

In a situation similar to yours, e-man, I hedged my bets by making the shorter wire about two-thirds the length of the longer one. That's quite a bit longer than I needed, but I didn't want to have the difference between the two be too large. (It also leaves me with a length that's not too short to sell, if I wanted to.) I loosely gathered the excess into a sort of figure-eight shaped bow. Someone smarter than me said this would be better than a coil-- maybe Bear can comment. I don't know if I've come out ahead in terms of sound quality or not, but over extended listening I have not noticed any imbalance or deleterious effect. If I chose to approach this like a hobbyist and experimented and investigated, I might or might not discover some subtle differences, but it's easy for me to leave this alone.