Can this set up be done? My headunit has 1 set of RCA pre outs. Does this meen i connect the amplifier to the RCA's and then my sub to the amp and i will be done? Or do i need to get splitters or anything? and in doing this does that meen when i adjust the volume on the cd player it will adjust the sound of the subwoofer? Sorry im new to all this 
Thankyou!
Thankyou!