Originally Posted by NickP
For 4 guage power wire - check out Home Depot - they sell it by the foot. Just make sure they have the fine strand copper stuff and not just the thick strand. The thick strand should work but its harder to twist and run. You'll also have to solder the exposed ends for the connection points.
ive never seen that at home depot, but if they do have it, it will no doubt be the cheapest you can get. just make sure you get oxygen-free copper wiring, they wont corrode very quickly at all. a good way to test that thick cable is to twist it - if you can tie it into a knot without much trouble, itll quite likely work fine. but like NickP said - do NOT get the thick strand wire! it has a much much lower current capacity. it may even melt under high current loads.
but if you dont want to re-do it later, i would suggest going to a car audio store and paying the extra 20c a foot to get the really high quality power and ground wire. trust me, you wont regret it. wiring is way more important than people might think. im running 2000w RMS (
) off a single 4gauge power wire - and im having no trouble. it does get warm on occasion, but never hot. a low quality cable would never be able to carry between 70-90A continuous (with 140-160A peaks) and live for very long.
a good RCA - you can pay hundreds of dollars for RCAs. dont believe me? Pear Cables
its insane. but if you buy a $20 cable from crappy tire, you can expect $20 quality. usually decent RCAs run $30-40 each. anything more than that is typically overkill. you DEFINITELY want to get these from a car audio store. "double-shielded" or "twisted pair" are things you should look for - those cables wont pick up much noise from the electrical system of the car.