if your just looking for added bass, dont worry about a head unit.. yeah itll help but unless you plan on rocking the windows or are willing to pull out your wallet for a clean sound, leave what you have.. there is a converter that hooks to your speaker wire and gives the rca outputs..id recomend the infiintys i said before, if not id do the jl. as stated before, the square subs give alot of noise but do not sound that great IMO.