I used to have a pair of 12's in my car and now I've go a 15 and on the same amp the 15 is considerably louder but it might be because the 15 is a competition sub. If you find out the displacement of the speakers which ever has the greatest displacement would be louder.
Depends greatly on the box. A cap is worthless. Might as well get rid of it while you can.
If both of them are on sealed, or both of them are on ported box, then the 12s will sound louder. But if the 12s are sealed, and the 15 is ported, the 15 will sound louder.
Depends greatly on the box. A cap is worthless. Might as well get rid of it while you can.
If both of them are on sealed, or both of them are on ported box, then the 12s will sound louder. But if the 12s are sealed, and the 15 is ported, the 15 will sound louder.