Speaker cable length

simao;
With the lengths you mentioned, audiophool BS aside, two different lengths will make no difference that any human ear can discern. The only real consideration is the gauge you use as it has more of an effect on the sound than length does. From my personal experience, 10 gauge tends to favor bass at the expense of highs, and 14-16 tends to be brighter. I have always had the best results using 12 to 14 gauge wire. If you are into making your own cables, check out http://www.knukonceptz.com/. They sell quality wire and connection accessories at realistic prices.

OP you can setup a simple experiment as I did years ago to determine the effect of speaker wires. Get a simple analog toggle switch and two sets of wire to compare. Have someone else switch back and forth without you knowing which cable is being used. A blind A/B test with instantaneous change from one to the other. It doesn't get any better than that. Everything else is just hearsay. I did this hundreds of times on Apogee Diva's and Klipschorn's along with other curious golden ears. We all came to the same conclusion.

There are a lot of other audio set-up aspects far more relevant than fretting over unequal speaker wire lengths. I saved considerable money on my 12ft/20 ft pair.

I don't mean to be acrid here, but those of you is spousing really short speaker cable lengths seem to be out of touch with a lot of systems reality. 

Welcome then to the Twilight Zone. None of this actually exists. Nor do I. Nor, interestingly enough, do you. None of this is reality. Couldn't be. No real person could ever figure out how to do this. Could they?
https://systems.audiogon.com/systems/8367

@millercarbon 

i'm always sus about people who've claim to have figured it out. no matter how ourt of touch they may be with interior decor