Was thinking of getting a 15 inch sub , was wondering if i could use it along with the 2 12s does anyone do this , use two different size subs?
I thought i would get lower and pound even harder , but i could be wrong, could i use them all in the same box (currently using a custom 8 cube box with 20 inches of port i think , the box is huge )
or would a single 15 be better than 2 12s ? i will have enuff power to run all three.
any help is appreciated.

 

Use the 2 12's with 4 cuft internal. You could use the 15 as long as it's not in the same box as the 12, and even then it might sound a little "off". It would make more noise, but you'd want a separate amp for the 15 also. That sounds dangerous to the woofers/amp. IMO if you're doing this, port the 12's and seal the 15 and place it somewhere not near the 12's. You could tune the 12's around 40hz for the "high-end" and seal up that 8 cuft box and see what happends with the 15, it might make up for the high tuning.

 

I personally hate when ppl use different size subs with there system, because I personally find it not sounding right... different basses from the subs. I use a single 9515 in a 4.4cf box, mine is tuned a little more for competing@ 46hz. I had it tuned to 36hz in last box, but that was my daily set up, my comp set up is in now. You need any advice about DD hit me in pm.

 

try it and let us know how that works out. really.

 

It can be done but you have to use a crossover and separate amps to make sure they play different parts of the bandwidth.

So if you have the 15 tuned low and crossed over under 50 you can have the 12's crossed over and band passed to only play 60-100 and have your high end on 120 and up.

Now with such a set up you also need to build the enclosures to compliment the frequency it will be playing, especially the 15 and 12's.

 

from what I have read and heard it doesnt work well unless in a van or big SUV