If I want to configure my system to sustain RMS levels at length, given the below parameters, how much power do I need from my altenator?
Kenwood 150 x 2 = 300 watts rms. This amp sees a 4 ohm load x 2.
Rockford 425 x 2 = 850 watts rms. This amp sees a 2 ohm load x 2
Sony 450 x 2 = 900 watts rms. This amp sees a 2 ohm load x 2.
So if I'm doing this right the total RMS watt requirement should be 2150 watts. How much amps does it take to produce this wattage and would this be the output required for my altenator? The chart your website provides does not go this high and I don't see a formula anywhere.
2150 watts times 1.33 (this allows for a 75% efficiency - probably high) equals 2860 watts IN divided by 14.4 equals 198 amps. You are not likely to be running even CLOSE to RMS for extended lengths of time, but there is the answer to your question.
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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."
Just remember a good battery can hold a 30 second discharge at 200amps and not drop below 10.5 volts. This of course will reduce your RMS since it falls well below the 12~14.4 volt rating. This is without the car running. A 130amp altenator can carry your system since most cars can not putout 14.4 volts with the rest of your electrical system needing some of it. Most will hold a steady 13.8 volts which drops your RMS output anyways. Also if you ever burn up a voltage regulator you will start burning thigs up. So upgrade your wiring to match your output at the Battery, Altenator and sound system. And always fuse everything.