Don't listen to me. (Unless you're WS6TA)
Feedback - http://www.caraudio.com/forums/buyer-seller-feedback/227670-treye.html
Also more recent feedback on caraudioclassifieds.org under same username and eBay as Willy8788 100% feedback.
Man up and externally regulate tht shlt ..i rest at 15.3
Optima's are crap. I had a Yellowtop in my last car, won't buy one again. Bought it new in August, fell to resting voltage of 12.2V by November. That's part of his current problem.
BUT, no one can really recommend what he should get, besides maybe new batteries, until he actually says what amps he's going to be using, and therefore what kind of draw he will be seeing. Blind guessing at this point. Need more info OP.
Plus subs are w7s so the odd ohms favors the ap3000
I mean I can get pretty loud like car alarms go off with it at 40 with zero drop but I got it set to go to like 58 before distortion and that's when the voltages will start to drop
58 before distortion??? what headunit is that? was it set with a dd1 or oscope to test distortion at the hu..seems high
But 4 of either of those amps is going to require some substantial electrical. No wonder you're dropping to low voltages running 2. You're going to need HO alt, multiple runs of 1/0ga from front to back, big 3 done in 1/0ga, multiple batteries in the back. If you buy new, absolutely no less than $1200, but probably more like $1800 or so. If you buy all used, you might get away with ~$1000
Possibly your alternator is going. My f350 would dim heavily when using my MM plow. Replaced the alternator and problem solved.
Smokey the Deer says downed power lines are bad!!!