Speaker Dimple

Not true in my system. Imaging is spot-on.

It would indeed be more subtle than that.The dimple is a weak point that will succumb to flexure. The other issue will be dispersion. Think of how a phase plug or a waveguide changes the off axis response of a driver - same thing with a tweeter.

It is easy to show there will be a difference. For example, if your dimple is 1 cm deep right in the center of the tweeter then you will have quarter wavelength cancellation and a dip in the on axis response centered around 8500 Hz. This is probably not as bad as increased breakup or flexure though - as it may simply resonate/flex rather than behave as a piston and lose high frequency output/efficiency.

Remember that ring radiators do behave differently - so a dimpled tweeter will too.

Once you fix a soft dome then provided there is no permanent damage or crease then it should be as good as new (not unfortunately the case for a metal dome which will be toast)

Appreciate the responds. Guess I'll try to vacuum method this weekend.

One other suggestion, in case the tape or vacuum methods don't work but you really want to get rid of the dimple: get the smallest sewing needle you can find and carefully pierce the area of the dimple with the very tip. Angle the needle about 45 degrees to the surface of the dome and very carefully pull the dimpled area outward. Then heat the dome with a hair dryer on the low setting to finish the job.

Be very careful with hair dryer method.

I had to remove a dome driver from Dynaudio in the past because the driver is glued on the cabinet. If silk dome is heated up too much, it will deform. Looking from side, you will not see a perfectly round circle. Like heat shrink, you will have area that are recessed after heating up.

Fortunately I was taking out bad drivers, but I wished Dynaudio would have warned me ahead of time in case I was dealing with new driver.