My Mazda 323 (protege) 2003, has a stock alternator of 70 amp, but since I will install one 12" subwoofer of 350w rms, and amplifier of 250w rms and 4 speakers 90 watts rms each.
Maybe I (in some bass hit songs) will overload the alternator (using the light in the night and my A/C)). Does Mitsubishi alternators resist that?
the speaker RMS ratings aren't useful in current draw. just the ratings of the amps used. is that the only amp you are using in the system?? if so thats only 20 amps of current draw. that leaves 50 for the car, should be ok, but every car is different. you'll just have to see if your lights dim or not.