The lower the number, the wider the wire, and that’s the plain and simple truth when it comes to a car radio wire. Below are the top wires to use for radio installations:
If you are going to be pushing lots of sound, power down your car stereo wire to your speakers. You cannot depend on some wimpy number 34 magnet wire to handle the task. All this will do is burn it out and leave you with a system that does not work.
If you are going to be pushing power to your speaker system, you still have to depend on a heavy-duty wire to handle the load. Now, take a look at Gorilla wire and notice that it seems more like shield braid than wire, it is. Because there are so many individual strands along the outside which signals can be carried (signals are carried on the outside of wires) despite what your neighborhood “pro” may have told you about car speaker wire and how signals move along. If you are pushing more than 250 watts out of your amp, then it is better to go with the Number 14.
If available and if you are not going to be pushing as much power down as you planned, then you can probably easily use a number 16 gauge wire. It is a good size and will easily slide under and around various parts of your car that Numbers 14 and 12 won’t handle easily.
A more standard hookup wire, this will handle more radio installations for you. Provided you aren’t planning to push megawatts of power through it. If you go that route, then all you will be doing is asking for trouble as the wire burns up, as well as the pieces of the system to which it is attached.
If you can find braided number 18 wire then go for it because, as noted earlier, the signal carries on the outside of each wire and not through the middle so you have that entire wire surface through which you can push your power. Just keep it down.