Like the post title says. It's going to be an 18" Fi btl fully loaded. But sorry, I just now got the dimensions. For the bottom it will be 31"Wx20"D, the top will be 31"Wx20"D, and 16 1/2"H. I know with that front angle the sub more than likely wont fit, but I want it in front, and I want it tuned as deep as possible. I can adjust in a couple areas if I need to, This is just smallest most compact measurements.