power wire thickness

I WANTED TO KNOW IFI AM USING THE CORRECT GUAGE WIRE FOR MY APPLICATION I HAVE A 1200.1 JBL AMPLIFIER THAT IS 1200 WATTS RMS AND A POWER ACOUSTIK AMPLIFIER THAT IS 100 WATTS X4 RMS THEY BOTH ACCEPT 4 GAUGE WIRE I AM RUNNING 2 FOR GAUGE WIRES TO EACH AMPLIFIER AND GROUNDS ONE AMP HAS 3 40 AMP FUSES AND THE OTHER 2 30 AMP FUSES SHOULD I UPGRADE MY WIRE TO 1/0 GAUGE I AM GETTING A VOLTAGE DROP IN THE REAR THE FRONT OF THE CAR THE VOLTAGE IS 13.8 WHEN THE BASS HITS A DEEP NOTE FOR A LONG TIME THE REAR VOLTAGE IS 11.8 I AM USING A 2.4 FARAD CAP TOO

Why are you shouting??? CAPS LOCK, MAN!!! Yes, the power cable you have is acceptable. As a better solution, a #2 from the battery, with a fused distribution block for the amps might work better for you. The number 2 should be fused at the battery for 225A, and you will have fuses rated NO HIGHER than 150A in the distro block. This might help with your voltage drop issue.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."