...I find it hard to see anything in your picture, unless you're talking about what appears to be a faint line on the right side of the aluminum?
There is a faint line in the photo that I can't even see with a naked eye, but I took the photo at an angle to bounce more light off the dented area right next to the surround. It looks to me like something flat was bumped into the cone/surround area enough to put the flat spot in it.
I don't think the cone will move that much (it's the mid) compared to a woofer with a lower crossover point, but I wonder if there is enough distortion in the cone itself to cause side affects at high volume.
