I think Ill use 12. Also I read on bcae.com that anytime you move to a smaller wire size, a fuse must be inserted. Ok I have a fuse at 12 inches off my 4awg wire from my battery. This leads to a DB where I have two more fuses and the wire branches to 8awg. Now one of these wires goes into my 4 channel amp that has two fuses built in that combine to 50a, which is perfect. But my sub amp, kicker zx1000.1, does not have a built in fuse which means I need to add an external fuse at 50a correct? Bcae also says that 50 a can house 537 watts. So does this mean that my amp will only be able to withdraw 50a or lower. Causing it too drastically decrease in performance?