I'm really just testing out dirrent systems bro. My previous systems include 2 15 p3 rockfords, and 2 12 kicker cvx's. Haven't really been through and heard many subs, so yeah, I'm open to all opinions bro. I have a friend that had two fi btl 18s and the fi audio really impressed me on how low the notes hit. And I have the super tweeters in the rear deck, thinking on taking those out, and installing another set of components in back door which now doesn't have any back door speakers. By the way, my car is an 2002 grand prix 40th anniversary will post pics of how it looks.