what size of main power cable to use for two amps with combined power of 600 watts rms.the length of the run will be about 12 feet from battery to amplifiers.
use a 4 Gage, always reliable and always dependable. Its a bit larger but you will have no problems
you can do this 2 ways have a 1/0 gauge wire running from your battery to a distrubtuin block that can branch off into 2 more wires, 4 gauge or 6/8.. and have each wire running to an amp or the same exact thing, except with a 4g wire from the battery to a splitter dist. block running into 2 8g wires.. but i would go with the first way.. will allow better power flow and not have to pull as much from the electrical system... and make sure the in-line fuse is the same rating of all amp fuses together.. so say each amp is a 30a fuse in each make sure the in-line fuse is at least 60amps
i would use at least 8-10 awg.
