2 12" fi q or 1 15"mag
 

please dont shoot me for asking this but i am in a delima, i cant decide between two 12's and 1 15. the two twelves would be in a 5 cu ft box @28hz with a 2500D (1250 watts per driver), considering using 2 fi car audio 12"q's. my other option is to go with a single 15" in a 3.5 cuft @ 28hz with a 1200D powering (1200watts rms) and i am considering using the 15" mag that i have. which setup would be louder in the end?

would the 2 12's getting twice the power of the single 15 make a big difference?

(everything in my sig is sold, except for the mag)

well all other things being equal (sd, xmax, etc...), the two 12's will move more air than the single 15. The extra power is not necessarily going to make them louder...once a driver has reached it's x-max, throwing more power at it will only increase the chances of mechanical and or thermal failure. I like 15's myself, but I've found that two 12's are always louder, when it's the same brand/model, than the single 15. There's always the space issue though.

2 12's with 2x the power will definitely be louder than 1 x 15...

there isn't much to debate on that one... more cone area and more power. :smilie_da

x2 what Jordy said.

3x what jordy said

but worth $300 more of loudness? that is the question

That's absolutely up to you to decide if you have spare $300 :).