Newbie Q: speaker cable length? Different OK?

A 12 gauge copper conductor has a diameter of approximately 2 mm, as can be seen in this wire gauge table.

My kind of chart! :)

Yes, Al, to me, too. I felt kind of silly when I figured it out. I still had the 7/17mm figure in my head, and I had the cables in my hand!

Or this -- although I have no idea what THHN wire is.
http://www.lowes.com/pd_539969-295-20494145___?productId=50101716&pl=1&Ntt=6+gauge+insulated...

(not that I need 500 feet.)

Thanks much, all. (with some humor.) Al, I’ve read your posts, and they make the issues clear. Thanks. The ones I’ve purchased are these. Pretty beefy; some 7mm cable itself (17mm with insulation). So signal loss within the cable should be pretty low. I just wasn’t sure if there would be some kind of feedback incompatibilities.

The new one is $10 more, and Monoprice’s RMA is an unexpected great thing, as it allows me to position the amp in a much better, cooler place). So, I imagine that it comes to a decision of whether or not $20 more for a match pair is worth it. --But probably no need; as you say, jmcgrogan2, I expect these cables and speakers to be sitting right where they are for a long number of years to come. Czasivey, you’re right; I may get the bug to upgrade these cables one day (God forbid, I get drawn into this upgrade loop, although I think it has already happened.)

And on that count, let me ask, from the link, sufficient enough cables? Or is there a likely upgrade path in the future? They do seem beefy to me. Speakers are Thiel 3.6 (though I may have blown them already -- painful separate story), and Bryston 4B SST amp.

Thanks Al,

Among all things, that was most comforting to read of the Bill LeGall lead. That gives me a great option, and relieves my growing concern that I may have damaged what could be a vintage, difficult-to-fix set of speakers. We shall see if they are, once I get this finally plugged together. But at least I have options. The guy does indeed seem to be a treasure. (And in my old stomping grounds, no less.) 

Yes, who knows where they were getting their numbers. I just measured them, and each of the cables, red and black, are about 6mm -- including insulation. It was the outer cable that was about 16mm. --Actually, they'd written it accurately; I misread it.
Perhaps I will take them up on the option to return both and go with two 15's, in that there just might be a future upgrade day.

Wondering about the bare cables, since both amp and speakers will take a bare wire connection, is there any reason not to consider simply going to Lowe's, and buy something like this, plain wire? That example, a 6 gauge would yield like a quarter the resistance of the 12 gauge. (How'm I doing, Al? <grin>) Both speaker and amp would probably take down to a 0-gauge, in terms of size. Is it possible to simply wire them with such cable? (And the "non-metallic" reference, I presume to mean non-shielded, right?)

@czarivey is this the type of solution that you're referring to that you use?

@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? 

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 , would you consider the Speltz anti-cables worth pursuing? Recommended (particularly when you consider what I'm using now/returning)?

Adam, I did check out the website, then called. And you're right, he's a great guy. Talked at incredible length, and he seemed to be in no rush to jet me off the line. I ordered speaker wire today, Level3. Ironically enough,  went with two times eight feet. I figured out a different amp placement that's in the middle. So the whole question is no longer an issue; although you're right: He did say no big deal -- although only with HIS cables, no big deal. Thanks again for that lead.

@adam18 Sorry for the late reply. I'm reviewing this old post, and realize I never answered. You'll find this interesting, I've also become a huge Paul Speltz fan. I love the setup I have now, and the speaker wires. But what is interesting is that I upgraded the RCA interconnects (and only Series 1). And at that point the whole system came alive -- just on that IC change. I imagine that was the last of the weak links. One of my audio sources, TIDAL lossless streaming, has a section of their website to see if you can pick out which A/B choices in each the six samples was the lossless example. Try as I might, I could never hear it -- until the installation of the Level 1 IC's. At that point, I instantly heard six out of six. So yeah, thanks tons for putting me on to this
And @markeetaux , at that point, I had the amp set up in the right-hand side of an entertainment center, and because it was mounted there up high, it took about 5' to go to the right speaker and maybe 15' from the left. Shortly after this point, I decided to relocate it to a different section of the center, in the middle (down low). So that whole "different length" thing was resolved in favor of two 8' lengths. Thanks all.