Gdnrbob, thank you kindly. Qbndds, welcome to Audiogon!
As JL35 indicated this question has been discussed in a number of prior threads, and opinions vary. It seems safe to assume that no comprehensive body of experimental data exists on this question, encompassing a broad range of systems, rooms, listeners, and combinations of cable lengths. So all that is available is opinion.
It is certainly very possible, and perhaps probable, that it will make no perceivable difference either way. If it does make a difference, a majority of the opinions that have been expressed in past threads favors keeping the lengths equal. I see it differently, however, putting aside the question of the resale value of the cables.
The degree of virtually all explainable speaker cable effects (including those whose audible significance is debatable or doubtful) is directly proportional to length. That would include the effects of resistance, inductance, capacitance, skin effect, proximity effect, dielectric absorption, and propagation delay, among several others that could be cited. The one exception to direct proportionality to length that I can think of would be antenna effects, which in many and probably most cases won’t have any significance, and if there is any significance of antenna effects it figures to be completely unpredictable with respect to length.
Therefore:
**If** the cables are such that their intrinsic sonic characteristics and the interaction of their technical characteristics with the particular amp and speakers would result in the longer cable behaving in an essentially neutral manner (i.e., having effects on the signal that are audibly insignificant), then the shorter one will too.
**If** on the other hand the cables are such that the longer cable DOES NOT behave in an essentially neutral manner in the particular application, then it seems to me that there is no way to predict which of the following two alternatives will be better/preferable:
(a)Using equal lengths, thereby making the colorations introduced by the cables the same.
(b)Using unequal lengths, thereby reducing/minimizing the colorations introduced by the cable in one channel.
And in fact I see no reason to rule out the possibility that (b) might actually sound BETTER than (a).
The bottom line, IMO: Choose whichever alternative you prefer based on non-sonic considerations. And if you decide to go with the equal length alternative, as suggested by Gdnrbob it would seem to make sense to try to avoid tight coiling (or closely spaced paralleling) of the excess length in one channel. Although, again, that may not make any difference.
Regards,
-- Al