Well i'm kinda having to stick to audiopipes which arent the best subs in the world i understand that but was just wonderin what everybody thought wuld do best
Why is your Dad stuck on buying Audiopipe? Go to Ebay and show him all the options for the money. I've seen people get pretty good numbers on Audiopipes but it was usually right before they blew!
If you're going with 4 12's chances are you are taking the cheaper route (audiopipe) and not going to get the same quality subs as you would if you spent that same money on half the amount of subs. With that being said, DC level 4's model up great for bandpasses which is what you must be doing since it's a blowthrough.