Newbie Q: speaker cable length? Different OK?


Hi. This is a complete newbie question. I've ordered two 10' amp to speaker cables, but I really need 15' on one side. Monoprice (for better or worse) is willing to RMA the cable(s). Should I go with two 15'? Or is simply swapping out one 10' perfectly acceptable for signal?
donzi
Interesting. I wonder what the difference in composition would be between "speaker-intended" wires, and AC? Yet, that anecdotal "no one raved about them" is telling. Still, I would wonder. Copper is copper. Extruded is extruded. Just wondering out loud.
@adam18 , with your conversation with Paul Speltz, are you recounting that simply different lengths are fine? Or is that combination of 6'/12' (e.g., 7'/14') being some kind of acceptable harmonic, or something like that? 
@adam18 , would you consider the Speltz anti-cables worth pursuing? Recommended (particularly when you consider what I'm using now/returning)?
Donzi, I beleive I use bulk KImber 4tc unterminated cable. Using unterminated at least will give you a possibility to cut the longest one before you decide to sell. I didn't sell mine for over 12 years.
Interesting. I wonder what the difference in composition would be between "speaker-intended" wires, and AC? Yet, that anecdotal "no one raved about them" is telling. Still, I would wonder. Copper is copper. Extruded is extruded. Just wondering out loud.
It’s probably not possible to define a general purpose answer with any certainty, but presumably the reasons relate to some combination of factors such as those I cited earlier whose audible significance is not well established in a quantitative manner. And also in a lot of cases to differences in inductance, especially if (as I indicated) the impedance of the speakers is low at high frequencies and/or the cables are relatively long.

Regards,
-- Al