Vifa tweeter, wrinkled dome

[d1030180]

Hello

My question is simple: is there anything I could do to repair a "bumped" Vifa tweeter shown in the picture? Do I need to disassemble it somehow to straighten the dome back to its former shape?

Despite its condition the tweeter still works (somehow). Its model number is: Vifa D20TD-05-06. It has been discontinued a long time ago. In my loudspeakers the tweeter is paired with a 5½" midwoofer TC14WG49-08, also made by Vifa.

Any help would be appreciated...

 

[Oliphant]

Vacuum cleaner with the suction turned down very low ought to suck it back in to shape

 

[yajnaS]

Leave it as it is. You can only do more damage (bend the voice coil).

I've fixed that kind of damage by pulling with a bit of sticky tape wrapped on a pencil.

 

[Cal Weldon]

Try doing it with your lips first. Vacuum cleaners can be very mean to soft domes. Then try tape.

EDIT: I see yajnaS got there first.

Looks like you can pull the assembly with the 3 screws if you are careful and push it out after removing the dome/coil assembly. Unless it's glued as well that is.

Others?

 

[Radugazon]

Looks like this tweeter is easy to disassemble by removing these three torx. You can make it coming back then with a finger. Reassembling it correctly can be either very easy or a real hassle, all depends of the centering system and of the gap size. Is it ferro fluided ?
If problems, I secure progressively the screws while running a sine at say 1000 Hz. That's barbarian but makes easy to know if the coil is touching something.

If you don't feel comfortable with this or the vacuum methods, there is always the needle.

 

[David Gatti]

Suck on it with a straw.

 

[tuantran]

Use low heat heatgun to heat it up (make it softer) and use a small needle to make a small hole in the middle of tweeter and try to lift it up using same needle while you apply heat to the dome. Good luck.

 

[tuantran]

Continue to apply heat until the dome look good(do not apply too much heat)

 

[Rullknufs]

Use your lips, as Cal said. I've never tried myself but it feels like it should work well. You could also try with a straw as David Gatti said. I would wait with screwing it apart.

 

[d1030180]

Looks like this tweeter is easy to disassemble by removing these three torx. You can make it coming back then with a finger. Reassembling it correctly can be either very easy or a real hassle, all depends of the centering system and of the gap size. Is it ferro fluided ?
If problems, I secure progressively the screws while running a sine at say 1000 Hz. That's barbarian but makes easy to know if the coil is touching something.

If you don't feel comfortable with this or the vacuum methods, there is always the needle.

I went with this method and opened the assembly. The three screws hold the plastic front plate in place and underneath it is the dome/voice coil assembly. The voice coil assembly had three centering pins, so I didn't experience any difficulty re-assembling the tweeter.

Picture shows the result. There are still some small wrinkles but it doesn't affect the sound anymore. I am happy I could get my first pair of DIY speakers back functional.

Thank you for your advice!

 

[iamtheonlystevo]

Last resort is a dab of hot glue and something cold (screw head, nail head, etc) let the hot glue cool a bit and pull gently. The glue should pop right off

 

[d1030180]

On a (un?)related note; when I was de-soldering the leads on the tweeter I noticed the midwoofer's diaphragm surround had a small hole in it. I attempted fixing this by placing a tiny piece of self-vulcanizing tape over the hole from the inner side of the surround. Since the surround is also rubber, it seemed to stick surprisingly well.

 

[Rullknufs]

Congratulations!

 

[Radugazon]

I am happy for you.