I need to know if i can use low voltage landscaping wire for wiring speakers. I need to use this kind of wire because part of the wire will be run outside the house and needs to be weatherproof.
In fact, I'm using it to feed my subwoofers indoors as it is less noticable running across my dark colored carpet than the usual clear colored wire sold for speakers. As you said, it is 14 guage, and way less loss for long runs (likely outdoors) Most important, it is designed to be burried.
I use Carol brand 12/2 for my surrounds and it is just fine.
Bought a 100' hunk at Home Depot for like $20. Nice copper and the strands are a little thicker (supposidly better than the stuff with hundreds of strands).
Reguardless, it is fine.
I use the 12AWG Sound King stuff from Parts Express for my fronts and the Carol stuff in the rear. I have AR banana plugs on all ends (all speakers and the amp and speaker end). Not once have I second guessed this stuff.
I used something similar for a 100-foot run from a NAD C370 amp to JBL N24-AW speakers and PartsExpress-sourced subwoofer. Works fine. Just make sure the copper seems of decent quality and use some sort of sealed connector (I used a type that has silicon putty built in; once you screw it on the twisted wires, it self-seals permanently). Should work fine.
One more tip -- I ran 14/4 (four wires) so that all I had to do @ the end was split red & black (which I designated left hot and left negative) and yellow and blue (right hot and right negative).