Right size fuse

Bout a 40A fuse Paul

mpathy, 40A is too low, I think. If.... I = Watts/Volts I = 600W/12V (bare minimum, expect closer to 14 when the car is on) I = 50 Amps If you draw nominal power from the system, 40A should be ok, but when you draw more current, you could blow a 40A quite often. Or you could put a 40A in and just never turn your system up loud. Anyone else agree or disagree? DXAV

Truthfully, you can put ANY size fuse up to 150 amps. you DO NOT RATE THE FUSE BASED ON THE AMPLIFIER CURRENT, you rate the fuse based on the current capacity of the primary wire, in this case, a number 4, which will handle 150 amps. The fuse under the hood is NOT there to protect the amps, but to protect the car. HOWEVER, if you were to base it on the current requirements of the amps, then I would do the math like this - 600 watts at 50% efficiency is 1200 watts in, 1200 divided by 14.4 (the voltage with the car running) equals 83.33333333 amps, so I would put an 85 amp fuse in line, as it is a much more readily avialable fuse than an 83.33333333 amp fuse.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."

^^^ he's got it!