Cable lengths

Theoretically, there would be a timing difference in when the left and right signals actually reach the speakers. Whether this would make an audible difference or not, I can not say as the signals are both travelling so fast that your ears may not be able to detect the slight delay in one channel.

Regardless, I would go with equal lengths on the cables for at least 3 reasons that immediately come to mind: 1) You MAY be able to hear the timing diference, 2) Some manufacturers claim that their cables don't "work" in very short lengths. I tried to buy some 6ft MIT 750 cables once from a store and was told that MIT would not sell them in lengths of less than 8 ft. 3) Resale. It may be the furthest thing from your mind right now, but trust me, you are going to want to sell/trade these someday and will get zero interest/value if they are of unequal lengths.

Hope this helps.

Yup, go with the same length. The simple answer is that the damping of the two cables is different if they are different lengths, also your high frequencies may roll off differently. (And it's really, really tough to sell two cables of different lengths! :-))

Greg

ELSman: Another point you may consider, if you have not already, is that wire to an ESL has special issues. An ESL acts like a capacitor (C) in the circuit (unlike conventional speakers)and has a transformer as part of the speaker which is an inductor(L). This can cause an L/C resonant circuit and may result in an unwanted peak at high frequencies. You do not want high inductance in your speaker wire to add to this problem. Inductance is largly determined by the area between the conductors (in the speaker wire). A few folk I know favor coaxial design.

I am not a big ESL person but there are several at this site, Detlof, for one, comes to mind. Maybe they can offer better suggestions if you are not already familiar with the issue.

Anyway, this may be as important as the length issue.

Cheers
I remain,

If you're using a cable that's so resistive or (with speakers where it can matter) so reactive that an extra 12 feet causes an audible difference in sound, my advice would be to change cables. But if you are intentionally using your cables as a tone control, then yes they have to be the same length.

The timing difference really is too small to matter. Think about it: You can also create a timing difference by moving one speaker slightly closer to you than the other. Adding an extra 12 feet of wire to one channel would have the same timing impact as moving a speaker a few millimeters. (I'm estimating here, but I'm pretty sure that's the right order of magnitude.) Now, did you use a tape measure that accurate when you placed your speakers? And what happens when you move your head? If this mattered, audio would sound very weird.

Since the signal travels at the speed of light, there shouldn't be a timing difference but it's still a good idea to keep the lengths the same.