I got 2 type S subs. I got a JBP BP600.1 amp pushing them. One of my subs rattles when it hits at medium to high volume. What's wrong with my sub? Also it doesn't seem like they're that loud considering that it is 600 watts total. I can't really feel it when I'm in my front seat. I just think they should be hitting harder, could this be caused by whatever is causing the rattling in my sub?