Speaker repair or replacement

[Gwalsh]

Hi all,
I am new to the group, I have recently acquired a clairtone 7980 and have started the restoration process, with that said, I have noticed that the tweeters have torn or cracked cones. I was wondering if this is repairable or has someone come up with a replacement tweeter to use? Thanks for help with this issue.

 

[floyd]

These are piezo tweeters . they are a common size and could be replaced with a non piezo tweeter.
You could put a bead of glue on the cracks until there filled and just keep using the original tweeters.

 

[Gwalsh]

Thanks Floyd for the info. I am hoping someone has done a full speaker replacement in the Toronto area and could give me info on where to buy the replacements

 

[caution]

I used these as replacements: https://www.parts-express.com/Dayton-Audio-ND20FA-6-3-4-Soft-Dome-Neodymium-Tweeter-275-030

Once you remove the old cone from the shell, these new ones drop right in.
I posted some pics of this process here: https://boomboxery.com/forum/threads/another-c-100f-resto.28611/post-360533

 

[Gwalsh]

Thanks for the info, if I found tweeters with no resistance like the original one I wouldn't need to mod with different resistors?

 

[caution]

Piezos actually have a ton of resistance, around 1MΩ. No crossover capacitor necessary. They are already capacitive loads, unlike traditional speakers, which are inductive loads. I wouldn't bother using piezos, they sound like trash and have a shelf life. If you do get the ones at that link (or any small traditional speaker) I would use a 2.2µF bipolar electrolytic cap, or polypropylene, rated for at least 50V.

 

[Gwalsh]

Thanks for the update

 

[Gwalsh]

Hey caution, would it be safe to say that all the tweeters in these boxes are past their life span and should be replaced?

 

[caution]

Well, if it ain't broke don't fix it, but from my own experience, most piezos in the boxes I own have died and need replacement. Unfortunately it's not always that simple because of the space allotted for them. For example, the Discolite piezo tweeters are jammed into a very tight spot along the bottom and pretty much require replacement piezos.

 

[floyd]

Hey caution, would it be safe to say that all the tweeters in these boxes are past their life span and should be replaced?

Piezo tweeters are efficient with power. The trade off is sound quality.
Piezo get loud but the sound can raspy and distorted when pushed hard.