Are they on an amp? Are they installed in the doors or kicks? Do you have any midbass drivers? A lot of it is going to have to do with tuning also. With my stock components I was able to make it sound like there was a kick drum in my front dash. It took a lot of work and time though. There's a whole lot to be explained if your new to SQ/SQL, I would reccomend checking out diymobileaudio.com, if you haven't already. A lot of knowledgable people on there and helpful posts. Check it out.Alpine Type S 6.5" components up front, stock rear fill 6.5's.