Any idea what it could be? My first thoughts were something (a wire?) hitting the cone from the inside as it goes back and forth and that's why I took it apart. But it still made the sound when I played music with the driver sitting on the ground.
It's similar to the sound of taking a stack of paper and blowing on the ends of it to make the ruffling sound almost? That sort of buzzing.
That's what made me think the surround wasn't set all the way, or the cone wasn't glued all the way... Really not sure. One of their CS reps is supposed to call me today, I called them at 4:50 their time yesterday so he didn't have a chance to speak with me. Hopefully they have some spare Be drivers lying around and didn't sell out of all their spare parts too!