Terry Zagar wrote:

For live-sound applications, you will need to worry about multiple
connection-disconnection cycles, spooling and unspooling, people and
equipment landing on top of the cable, and people tripping on the
cable. Avoid zip-cord stranded wire for this application (too
fragile). Also avoid solid-core Romex wire (whether 2- or
3-conductor) (too inflexible). Instead, look for cable in a round
jacket at either 10 or 12 gauge, 2 or 3-wire that can take a beating
(e.g., orange or green heavy-duty outdoor extension cords with plugs
cut off). Other comments above also apply. For pro-use, you can also
try Markertek (http://www.markertek.com/) or Swee****er
(http://www.swee****er.com/index.php) for speaker cable (with Speakon
connectors as well).

Nice advice. IME, the biggest problem is gauge.

I use a 2% loss at worst load as a limit, which is a bit more than most
places recommend, but based upon personal and other tests, 2% loss
is about where everyone's mind can't tell the difference, no matter
how good your hearing is.

The oddness comes when a guy is trying to run his 6 ohm speakers
that dip down to 3-4 ohms through 16 or 18 gauge wire. Sounds fine
for the fronts, but even a small room will easily end up with
30ft or so runs to the rear surrounds.

So he tries different cables, and gets different results as he's
pushing 10% loss or greater at the rear speakers. At this point,
resistance and other factors become apparent. If he'd used large
enough wire in the first place, any differences in the wire
would be rendered too small to hear.

ie: why pay for fancy 13-14 gauge when common 12 gauge wire
will pass every test the same or better, OFC cable with special
shielding and such or not. At 10-30 cents a foot, it's pretty
simple to just buy a roll of Romex or 10 gauge wire.

10-12 gauge is usually sufficient for most speakers, but I've
installed many 6 and 8 gauge setups as well. Given how cheap
large enough wire is, this is really a no-brainer not to use
larger gauge common wire.

The 2% also gives a bit of leeway for connector boxes and
wall jacks and such - there is a 1-2% combined loss if you
are using wall jacks. This is still well under the 5% maximum
recommended limit.

I personally like 12/3 Romex for attics and under houses. Tacks
up nicely and is weatherproof. Terminate to a fancy wall jack
and uber-expensive looking patch cable that's just long enough
to go between the speaker mount and the jack. Impresses the
friends and makes it easy to switch speakers later on if you
wish.