i just got a alpine type x component speaker set and i am looking to get some 10 or 12 inch subs in the near future, i have the componets installed on my rear dash and i would like to get a amplifier for them that i will be able to hook my subs up to when i get them. the components are 4 speakers will i need a amp so i could run a channel to each mid and tweeter set and then i have two channels left over for the subs??