Phasecorrect...Get ready for a broadside from Sean!
I have 12 inch Titanic drivers, combined with 15 inch JBL drivers in my SW systems. The Titanics do the job for me, but my job is a bit "different"...to "tune" the 7.5 cubic ft enclosures which house both drivers. The Titanics are driven by their own amps, which have gain, phase, and frequency response control.