Four speakers may be 4 50' runs, but if wiring is going to be outdoors, then it should be outdoor rated wiring so that moisture does not permeate the shield and affect the wiring.
Outdoor direct burial cable is available at a very fair price at
http://www.outdoorspeakerdepot.com
Specifically...
http://www.outdoorspeakerdepot.com/12ga2buca100.html
They also have a 500' roll...
http://www.outdoorspeakerdepot.com/12ga2oxfrbus.html
I would not worry about 10 vs. 12 vs. 14 gauge unless you have top shelf speakers in a properly designed room. You simply aren't going to get that much signal loss at that distance and won't have the environment to hear any signal loss. I've got a setup I work with about 30 outdoor speakers running the wiring about 200' per run, and I think the installer was using 14 or maybe 16 gauge cabling, with no ill effects.
Thanks for the response. I was trying to simplify things in the previous post. Here are more details: basically running speaker wires through exterior wall from living room, around the house (OUTDOORS) to two zones:
Zone 2: 2 outdoor speakers (JBL
http://www.amazon.com/JBL-Northridge-Weather-Resistant-Bookshelf-Speakers/dp/B0000632G7/ref=sr_1_1?ie=UTF8&qid=1305665070&sr=8-1) in outdoor patio, under and awning that is about 75 feet run (estimated as total distance considering path the wire has to run) would like to install a outdoor volume control by the sliding door.
Zone 3: 2 inwall speakers INDOORS (Infinity
http://www.amazon.com/Infinity-Ers-210II-Wall-6-25/dp/B0009PX4UO/ref=sr_1_6?s=electronics&ie=UTF8&qid=1305665150&sr=1-6) but the wires have to run OUTDOORS around the house for about 150 feet (estimated considering the path the wires have to take).
I think 14 gauge will suit my needs as these speakers are going to be used mainly in party mode for ambient music and not critical listening. My concern is more for the safety of running the wires outdoors and mounting the outdoor speaker which will be under an awning, but has the possibility of getting wet from rain/wind.
I bought this CL2 2-conductor wire from Monoprice:
http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10239&cs_id=1023902&p_id=3845&seq=1&format=2
1) Sounds like CL2 is not enough and I should be getting the outdoor rated wires from BMX's post? If this is so I will try to return the wire and buy from his link. Really appreciate that link because they're located in Brea which is not too far away from me.
2) If i go with the wire posted by BMX, will i still need PVC or EMT piping, or is that good enough? I live in Souther California, the house is in Fullerton. We don't get snow or crazy weather out here.
3) Do I need to do take any additional precautions for the outdoor speaker wiring? I'm guessing at the very least to put electrical tape over the binding posts/wire, but I'm worried about the rain/wind.
4) Any additional issues for outdoor volume control knob? I'm running it to a Yammy Aventage A2000.
Thanks for all your help. Yesterday we got a bunch of quotes for wiring/flooring/painting/etc... as a new home owner I'm pretty low on cash right now.
The quotes from the home theatre installers were too high (~$1.5k just labor, no materials) so I'm going to be doing all this myself. My wife gave me till the end of next week to do the wiring before she sends in her crew for painting. Yes, I know.. painting is easy but we don't have time as we're both pretty much work 6-7 days a week. Thanks again guys =)