
Originally Posted by
jhnkvn
Gapang bass is more of a characteristic of proper box design rather than the subwoofer driver itself. Google "ported box tuning" for more information.
As for which drivers, 4x12 will win over any single 15 incher hands-down. You can move more air while the drivers has less vertical excursion - this is the huge advantage of more surface cone area. The question now is whether you can properly provide ample power or not.
JBL GT5 subwoofers are actually very good. A lot of their features are trickle-down features from their highly rated GTi W12 subwoofer. You're getting a lot for a cheap price and it's one of my favorite budget subwoofers in a decibel match.