SDC11315 

+eaglewitharifle it's a very noticible improvement yes, but outside the car it sounds horrible, like a ghetto car. So I would not do it again (i bought fiber enclosure for 50 dollars).

+Kristof OK, was it the fiber enclosure that made it sound bad from outside? Would it be better if the enclosure is thicker?

+eaglewitharifle No, it's the trunk itself which is too much isolated which makes the trunk shake. the bass in the car is ear killing though.

+Kristof OK, thanks for the replies. I am going to attempt the project and play around with it keeping the base down. I too don't like it ghetto, and I need the system stealth.

+eaglewitharifle I'd recommend you to buy a custom fit speaker system for E9X (like Gladen audio here in Europe), which has amplified underseat subs.