The fabric covering the front, as in "right boxes", stretched over a frame, and it is removable. Behind you can see only a small round speaker (5cm), but that's obviously not a scrap. The even has a real rubber surround, as it is otherwise known of in high-quality speaker systems. Looks like a real woofer, only much smaller. And can something! Even a quite satisfactory bass has what you do not want to believe in these small dimensions, but is so.
As I said, "big boxes" are not (it should not at all be), but as "Brüllwürfel" those things are quite excellent and I give no scruples full five stars!