The sub fires downward and the large opening at the bottom is where the sound comes out. This is the same way sealed enclosures work under the back seat of an extended cab or four door truck. As far as timing goes I never mess with it as its not something that bothers me similar to mounting a tweeter 90 degrees off axis from the mid. Is it better to compensate for it? I'm sure it makes a difference but I'm not willing to spend the money or time to tune the system with additional gear. As far as imaging goes I've always felt that comes from the mids and highs more than the sub. The bass presence will naturally be affected by the location of the sub and the direction it fires.
I wanted a center console look with the punch of a 12" sub and it delivered so I was happy with it.