ok first of all thanks to anyone who can help me out with this, my situation is i have already bought and installed my new head unit and replaced all my stock door speakers with brand new pioneer 4 ways(6x8), i am now looking to buy 2 12" subs and an amp, i have already decided which ones i want and have determined i am going to need a capacitor i just need to know," if my head unit only has 1 preamp out,will i need to get anything else to power my 2 12" subs,amp,and capacitor?