I like the fact that there is a little bit "extra" happening here on your first box. The size seems a little large for those subs, but if several design programs give you the same numbers, go for it.....
The lighting is a nice touch for a first box as well, putting a pair of plexi windows in the middle of a bamboo covered box is an interesting contrast. There will be those here who give you a hard time about the box, but showing some creativity and a willingness to try something beyond the basics for your first try is a good omen for the future.....
I hope it sounds good to you, it will be interesting to see what you come up with for your next project.....