def loudness

Or maybe 2-D3100 would help out too...right. Should I run my VP Power Cell along with them too? Or try to sell it.

I've got 3-15's...1-DD9515 & 2-Crystal CMPX2 15's. They're in one big enclosure divided chambers, both chambers tuned @35hz. I've got a Optidrive 4k running the 2 Crystal's at .5ohm, a Audioque 3500d running @1ohm to my DD9515, and a 4x150 amp for my highs..mono blocks @14.4volts should produce +-8.5k-9k watts. Got a Duracell deep cycle under the hood and a VP 2500 Power Cell in the back along with a CS144 high output alternator made locally...110amp at idle and 225amp at 1500 rpm...0ga big three done. 14.5volts regularly when listening full volume for a minute, volt drops to 12volts...would one of the D7500 help out my voltage drop, or would I have to go with two batteries in the back.