How to tell + and - on rca cables

[p8ntblr]

I got an old bose speakers I'd like to hook up. There are output lines are hard wired to the subwoofer (can't disconnect) and the ends are rca terminals which connect to the rca terminals on the satellite speakers. I already have some speaker wires running through the wall. I planned on cutting the rca terminals, connecting them them to the ends of the wires coming out of the wall and connecting the wires from the subwoofer to the other end of the speaker wire in the wall. Wow, what a run on sentence. So here are my questions..

1. How can I tell which is the + and - from the rca terminals
2. How do I connect the speaker wires? Just twist them together or would soldering be better?
3. Is it a big deal is if the wires are a different awg? 16 and 18 awg.

EDIT: Nvm about #1 I just used a voltmeter with a continuity tester.

[LCHIEN]

generally the center pin of the RCA phono jacks are considered positive and the outer ring is considered negative.
generally with speaker wires the marked wire of the pair is considered positive... either marked with raised ridges, or a color stripe, or the gold wire if clear insulated and silver/gold conductors.


I would not "just twist them together", at the very least use a correct sized wirenut, otherwise its better to solder, but a wirenut will do.
No big deal if the wires are not matched in gauge.

[Mr__Bill]

On RCA connectors, center is signal and outer ring is ground.
Really doesn't matter if switched as long as both speakers are switched, out of phase will happen if only one is switched or cross wired.

For long runs heaver wire is better, less signal loss and distortion. go with the 16 awg. but no, it doesn't matter if different gage wire is used on a short run.
If you twist the wire and wire nut it, don't touch the wire, oil from your fingers will degrade the splice over time. Soldering is better but not required

What you don't want to do is short the wires together, you will blow the fuse or worse if you do with the power on.

What many do is use common zip cord.. ie 16/18 awg extension cord, remove t he ends put a twist in the wire and splice them in. It is often cheaper to buy a 25 foot extension cord than 25 feet of just the wire.

hth
Bill