would a XS Power D7500 be enough?yes in conjunction with extra reserve batterys - and your playing habits also factor in.sitting parked in a parking lot doors open you not in the car - engine idling at normal engine idle rpm = not 370 amps as the engine needs to be set to rev up to about 1500 rpm ish to reach that level of output capablity of the alternator.....
my system planing math is super rough but semi acurate - take alternator power + battery amp hours rating times 10 = total system wattage
so 370amp from alt and 130amp from battery would be the bare minimum id recomend to run a system totaling 5k rms value.
using a battery bank of 250 amp hours rating would greatly increase play time and help with voltage drop in a 5k system
using what alternator ? your stock 100 amp alternator ? a 370 amp unit that actually makes 370 amps ?So What would I need Battery wise to power 5000 watts?