Ah, yeah, looks like it didn't get sealed, or not all the way. Then if there is 'something' shaking inside, it is probably some wires or parts floating around. You could pull a driver off an investigate, but, I would recommend not. Send it back, and... consider your options (can let them fix it or find another brand).
To me, QC is really important to a speaker company. While I was searching for your problem, I saw they sent Audioholics one with the wrong driver in one spot, another user had tweeter problems, now yours is..um...returnable under US implied warranty law lol. That said, Audioholics gave them good reviews, and, *shrug* could be isolated incidents?
Speakers aren't hard to make, good speakers are, so, when you go to these smaller builders you can either get a great value from low overhead or a dud.