So I just upgraded my alternator to 270amps with a big 3 upgrade as well. I have a pair of 12” SSA Icons. My box from GP is on the way to put them in. I have a sundown 1500d amp to run them. Now I’m asking for what direction I should go next. Get a 4 channel amp for my door speakers or get a battery for the trunk? Yesterday I put some sound deadening in my trunk and I’ve noticed a difference. I want to do my whole car but I figured I’d buy a battery or amp first. Any recommendations?