Today I got my K140 reconed as 2235H. I started to break them in and one work perfect.
Unfortunately the other one makes some clicking noise. Its not loud and not really clicking. It's like fluttering with something touching the cone. Checked the wires, ok.
It seems to come out of the dust cap inside the voice coil. When I'm moving the cone there is no sound or scratching.

What the h... this could be?

Thanks for help