The only way to know for certain whether or not the diaphragm is warped is to separate the two halves of the driver frame in order to lift out the diaphragm. It's tricky and not without risk. I linked a video in Post 1 of this thread showing how to do it. This should be considered the last resort for a problem you can't live with. Good luck which ever way you go!
12/3/15 at 5:39am