Can you put ,lets say 2 12" subs and 1 15" sub(or 18") and have good sq from the 12's and good spl from the 15?Do you have to have seperate amps to do that?I like real low bass like from the 15"s and the 18"s,but they do not have enough sq like the 12"s do,so do yall think this will work well?
I've mixed 2x 12s and 2x 10s before; I felt it was a great mix for rock/metal/techno. It brought me deep bass when I needed it and punchy response during kick drumming and other ambience bursts. Although I will say that the 12s I used kept up with the 10s just as well...
i wouldn't do it, mainly because it's hard to predict what kind of sound you'll get if you mix things like that.
if you want to go deep, use a large, sealed box. if you want to go loud, use a ported box. if you want to go loud and low, use multiple subs in sealed enclosures, but i can't see an advantage in mixing sub sizes, IMO.
in that case use 2 12"s and run them each with a lower rated amp, preferably class ab amps.then just tweak the subsonic filter and gains, etc, or even better, wire one of them to a crossover and u will be able to tweak one for what ever bass, while keeping the other for different bass