Wow Kranny, your answer to a 29 post noob, me. There more post´s of you in this style, in the last times.
That is like the big 12 K post Kranny, tell the "I know alot, but have only time to spit about the other posts and ,
till another SMD member give you the right guess and maby i give a blessing on this if i want.
Thats superficial, unperceptive and a little arrogant. Have this to be in this form from you?
I try to do it better and give a 2nd guess.
To the Op, on your side i would take a 15 from the IVX D 4 subs and run him on http://www.ebay.com/...499%2520W&rt=nc a Alpine MRP 450.
There is one for 65 $ and if you want + 11 for warranty and another in auction.
I guess you the 15 in case of the more conearea = louder. Build a proper box and your brother will have a nice substage for near 200 buck´s.