Quote: Originally Posted by
popsson 
if you have a good head unit(mines stock) do you need an equalizer to control your subs? or does the head unit take care of all that
unless your stock head unit has dedicated subwoofer controls and a dedicated subwoofer output (it does NOT need to be RCA jacks, most stock subwoofer systems run the amplifier audio wires a part of a wiring harness). if your stock head unit does not have either of those, then it will not be able to independently control the subs.
also, while some 'upgraded' factory systems are decent, the vast majority of factory head units are garbage. they usually have underpowered internal amplifiers and a poor EQ curve. they remove the bass at higher volumes to protect the cheap factory speakers from blowing, and to keep the sound 'clean' (good bass requires more power than most factory HUs are capable of producing, cutting the bass out prevents the sound from becoming 'muddy').
you can add a subwoofer to it , but it still will not sound good because the stock HU will reduce the bass at higher volumes (which will also reduce the bass output from your subs). to fix this you need to buy a sound processor to restore the bass and correct the poor EQ curve, and externally amplify the speakers.
