What do OFC and CCA mean? I know what a big 3 upgrade is. But I want to make sure I do it right.
Car audio wires typically come in 3 flavors
1. OFC, or oxygen free copper. i.e. purified copper - wiring grade. This is your standard wire and what OEMs use. You can use welding cable and it will be sized appropriately and OFC - typically has a cost advantage at the expense of flexibility.
2. Tinned OFC - the expensive stuff, can also be called marine grade. This is copper wire that has been tin plated. The plating is thin and doesn't show any measurable difference in conductivity, but it acts to give the wire fantastic corrosion resistance. This is what I use, personally.
3. CCA, or copper clad aluminum - the cheap stuff. A sheep in wolf's clothing. This is aluminum wire with a coating of copper on it, typically found in a ratio of 90% aluminum 10% copper. It's generally at an attractive price point, somewhere around 60 to 70% the cost of OFC. Whereas you might pay $3.50/foot for good tinned OFC 0 gauge, CCA would be closer to $2/foot. The issue with this wire, is that copper and aluminum are well known and documented to cause galvanic corrosion to each other. In other words, this wire rusts from the inside out. Due to the aluminum, it also doesn't solder. So that means if you want to use it, you need to invest anywhere between 60 and 100 bucks on a crimper and lugs. Which brings me to a point I want to make on termination
Take pride in how you terminate your wire. Either grab a blow torch and learn to solder open ended lugs, or invest in a hydraulic crimper and use closed ended lugs. Please, for the love of god, do not half ass it and use pliers or a bench vice or hammer thing or bolt cutters or any other nonsense. I don't care if the neighbor does it without issue. That just means he hasn't had an issue yet. If I had a dollar every time I was diagnosing wiring and found it was due to someone's lame termination, I'd be a rich man. Without going into great detail, a good connection should be gas/air-tight. In the case of solder, the solder bonds itself to both the wire and your terminal lug, acting as an intermediate. In the case of a crimp, the pressure applied is great enough to actually cold weld the wire. If you need more clarification or want a run through of the pros/cons of each method, let me know! I have a fair bit of experience with the stuff. Wiring that I've done nearly a decade ago when I started is still in service today in perfect condition. Do it once, do it right. Chasing wiring issues will make you more sad than anything