if you want a crisp base, get your self some 8 inch subs and stick them in your car. turn the frequency to all, that will kick ass for the crisp notes, then leave you 12 s or what ever as normal on low. you cannot relay on one or two subs to do all of the work. there are that many frequencies tp base that you do need to buy alot of ranged subs, thus when you see a good install they have alot os different sized speakers happening.
Uncertainty or not knowing causes depression, Im happy because I know I'm going to die one day!