Now that I have my setup being slowly built I have component 6 1/2's in the front being powered by a Kenwood 100W @ 4 ohm amp. My problem now is that I get a lot of rattles in the door area when I turn it up now. Should this be normal? It really bothers me. I’m thinking about putting in a 8" sub behind the passenger seat with good power (I don’t want everyone else to hear, I just want some good base). I’m worried that other things will start rattling with it.