Hey I am running a solo x with hifonics collusse 0 gauge all way round big 3 upgrade then to my yellow top in back, ground and power from amp connected to battery ; maybe I should find a separate ground in back for amp, here's what happeneds if I pump it right now it pumps ok, when I put the battery charger on the back overnight, the morning comes and I test it out, everythings flexing like crazy bass just pumping... For 5 minutes then it's back to not as much power front battery gets 14.4 volts with alternator so my charging system should be fine what I'm guessing is because the amp is so power hungry it needs a separate ground??Also heard yellow tops crap the bed sometimes but I'm pretty sure I'm getting 13 volts in the back.. Thanks for any answers