what one sub will sound like 2 12’s?

  I have 2 12" type r subs powered by a directed 1100d amp in my convertible mustang, they are in a tiny sealed box, im thinking of putting the type r's im my girlfriends 02 mustang hardtop because it has more room for the right box, if i put 1 type x 12" in the right box will it hit as hard and loud as my two r's???

One type r can hit harder and louder than two...in the correct box of course.

you could go find your self an old fosgate power hx2 or get a new fosgate t1 12  the type r s do hit pretty hard and sound good with the correct encloser

Make sure max spl is the same or greater with the single subwoofer than with the pair. Compare the sensitivity, power handling, and excursion capabilities in the correct enclosures. WinISD can help greatly with this. Frankly, a lot of it will come down to sensitivity. If you can find a single subwoofer 3db more efficient than the type R's, for the same amount of power (and like enclosures) the single subwoofer will be at least as loud. Find something that handles an adequate amount of power and won't go into over excursion, and there you go. I believe your type R 12" is 85db efficient. Find a 88db efficient or better subwoofer that handles a decent amount of power. New Project: 2003 Pathfinder

i would say to kicker l7 10"s or 8"s they pound hard or you could go with one solo x 10 kevin

Loud nad darn good sounding, the DD3512 which will also handle the power that that amp of yours produces. Top Secret, I can tell you but then my wife will kill me.