ok i already did the big 3 on my car but im still waiting for my fuse to get here so the part with the alternator to battery isnt complete yet but the grounds are. today i bridged my 2 channels into powering 2 subs at 470 watts. before i had each sub getting 270 watts

i didnt know how to wire them till yestuday so now they get more power. ok today in the morinig i was playing with my system and then it just turnes off

the voltage meter said low and the system just turned off. it turned on again but i need something else so theres less voltage drop. what else can i do besides a new battery and higher amp alternator?????
thanks for all the help