Speaker Dimple

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.

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.

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

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)

I just used the vacuum method on a pair of Totem Mites I picked up in a thrift store for $35.00. I put two fingers in front of the hose to prevent a perfect seal should the nozzle come in contact with the dimple. Worked perfectly and after running them in for a while any sign of a crease was gone.

The purpose of the dome is dispersion.

It is very possible that your defect is inaudible.

The biggest problem with the dimples is that they affect dispersion and subsequently imaging.

If you listen to a single speaker at once, you may not be able to detect any difference- as the actual driver is behind the dome. However, if you listen in stereo you will find things to sound erratic and imaging to suffer.

Good luck

With the vacuum use the bypass opening usually on the wand to regulate a lower amount of force.

Use a guard of some type or rest your arm against the face of the speaker, hold the vacuum nozzle firmly in both hands and gently move the nozzle toward the dome. Don't get too close or you are going to have difficulty controlling the nozzle

I read about that method in Dr Comfort's "Joy of Audio" - never tried it though ;-)

I've used the tape and vacuum methods over the years. For me, vacuum was easiest. As Elizabeth stated, just get close, don't touch the speaker dome. Use a guard of some type or rest your arm against the face of the speaker, hold the vacuum nozzle firmly in both hands and gently move the nozzle toward the dome. Don't get too close or you are going to have difficulty controlling the nozzle and you may end up causing more damage that you originally had on the dome!

BTW, it might help for you to practice first without the vacuum turned on. You can also just practice on any other surface with the vacuum tunred on so you will know at what distance the vacuum pressure becomes difficult to control.

Enjoy,

TIC

Used and not so sticky Scotch tape - try something not sticky at all first and gradually work at it using scotch that is newer or stickier until you can just get enough stick to pop it out.

Don't start with duct tape or something powerful as you may damage it. As far as audible - for sure this kind of thing is audible as you will get breakup modes that you normally would not see in a proper dome. It would sound like digital hash. As anyone who has pushed in a ping pong ball can attest to - once you break the spherical shape it loses strength/rigidity.