I have an Alpine CDA-9833 head unit, Polk Audio 6.5" in the front speakers, Infinity Kappa 6x9" 3 ways in the rear speakers, and an Alpine MRV-F540 amp boosting them... The box is 1.25 cubic inch sealed w/ one Alpine Type S 12" Sub, powered by an Alpine MRD-M301. My midrange sounds real good, but is the Alpine Type S 12" sub going to give me enough to be satisfy with???