Big project in small Civic package

If you buy from pawn shops say good buy to your warranty and tech support. Who knows if it will even work. Also you might not even get a manual and who knows how much abuse the last people have put on the product. Its ilke buying a demo product from Best Buy( I swear people hit those products with baseball bats with the abuse they get).

the lower the gauge of wire the thicker it is. If you have a 600 watts RMS (continuous power) amp then you will definitely need 4 gauge. If you have a 600 watt max power amp then you will probobly need anywhere from 8 to 10 gauge wire. To figure out the current draw of an amp take the total amount of RMS power of your amp or amps and multiply it by two which would give you 1200 watts if your amp is 600 watts continuous. Then take 1200 and divide it by the average current of your alternator(13.8 volts). This would give you around 86 amps of current draw. This would probobly too much for your honda alternator(it probobly is around 60 or 50 amps). You dont need a 600 watt amp to get some good bass though. If you bought two 10" or 12" JL audio W0 subs (which cost only about $125 each) and give them 250 to 300 watts RMS and you would bump pretty good for not that bad of a price.