Hi pakwheelers, I am in serious need of some assistance. I have a panasonic cq-rx320 in my car with 4 speakers already installed. I want to install a subwoofer as well. Can anybody please suggest me do I need an amp for that? The woofer that I want to install is 1500 watts. PLus I also need to keep the 4 speakers connected as well. Your suggestions are highly appretiated.