I am running four 15's in my current setup. 2 Quantum, and 2 Vega, simply because that's what I have, and they are in two separate 12 cube enclosures, with each sub in it's own individual chamber. It's walled, and tuned to 35 hz. That is what I listen to. For THIS box, I am gonna pick up another set of Vega's.
The alternator is new, albeit only a 105 amp, The wire from the alt to the batt has been upgraded. Let me stress that there is still a Long way to go, but all my current issues will be addressed next. One thing at a time.