Thanks, but I think you got me wrong. I meant to ask if anyone has installed a sub in the rear deck factory sub cutout location where the JBL sub goes.
I have a sealed 12" now. That is my favorite setup too which is why I am on the fence about changing it. Mostly I am thinking about the trunk space I will gain back however I do have quick connects so I can just move it if needed also. (Of course I still need to put that sub somewhere else in my car if I need the trunk space and when the seats are down there isn't much space left to stash it in the meantime.)It can be done but infinite baffle/free air subs can be tricky. Proper baffle work, treatment and deadening are key to quality sound. They can sound exceptional when done correctly; however, they generally won't handle as much power as when in an enclosure. If you only listen at reasonable levels with brief jamz when that certain song is on it is not an issue. If you want to flex the panels of your car while entertaining the neighborhood or like hours of play at ear killing volume then free air isn't they way to go.
Fee air is how I plan to upgrade my OEM JBL sub eventually. My favorite setup is a sealed 12" sub but I never need the spl, just the sound quality. Having the necessary work done by a shop can be very expensive. Usually more than having a box built. Not all shops even know how to do it properly since it's not requested very often. I have done a few fee air setups and I know that one upgraded 10" will be more than I need.