Power Wire Size - Directed Electronics Precision Power A1200/4 Owner's Manual

load, double its 4 ohm RMS rating. These amplifiers will effectively
double their power at this load.
1000W X 1.5 X2 = 3000 watts
3000W = 250 Amps total current draw
12V
If you are using more than one amplifier, add up the total current
draw for all of them and choose the appropriate gauge based on the
grand total.

POWER WIRE SIZE

A minimum of 8 gauge or a maximum of 4 gauge wire is
recommended dependent on the application.
The ground wire must be the same gauge as the power wire.
12