I have a distortion in one of my tweeters on my 3-way. The distortion occurs only at certain frequencies and above a certain volume. The distortion is pretty deterministic, I can reproduce it. They are old 3 ways energy speakers from the 2000. I managed to isolate the distortion problem : it is only one side, and because I can bi-wire it, I can confirm that the distortion is coming from the tweeter and not from the mid or bass (because mid and bass share the connector).
I also swapped sides of the amplifier, so I know it is the tweeter on the speaker and not the amplifier that is problematic.
The screw to remove the drivers are not accessible (see: https://rvb-img.reverb.com/image/up...,t_large/v1639605839/olidljagmyhg8zmbkcx4.jpg), so I would like do the debugging and part sourcing before taking them apart.
Is there something I can do to pinpoint where the problems, i.e. crossover, dome, magnet, voice coil? And the potential solution?
Thanks
I also swapped sides of the amplifier, so I know it is the tweeter on the speaker and not the amplifier that is problematic.
The screw to remove the drivers are not accessible (see: https://rvb-img.reverb.com/image/up...,t_large/v1639605839/olidljagmyhg8zmbkcx4.jpg), so I would like do the debugging and part sourcing before taking them apart.
Is there something I can do to pinpoint where the problems, i.e. crossover, dome, magnet, voice coil? And the potential solution?
Thanks
Looks like the driver is either rear mounted, or has some type of escutcheon plate covering it's mount.
You can eliminate the crossover as a problem by directly testing the driver.
The most likely cause of the problem is a dragging voice coil.
The cause could be a shifted pole piece, debris in the magnetic gap, voice coil misalignment, or coils partially sloughing off the voice coil former, or deforming from heat if no former is used.
You can eliminate the crossover as a problem by directly testing the driver.
The most likely cause of the problem is a dragging voice coil.
The cause could be a shifted pole piece, debris in the magnetic gap, voice coil misalignment, or coils partially sloughing off the voice coil former, or deforming from heat if no former is used.
Depends on the cause, the drivers construction, and availability of replacement parts.
If this is like the Focals, you remove the driver under the tweeter and then reach up to find a large nut holding the tweeter in place. It would be easier if you could see it... 😀 But it should be rather big and easy to feel.
I found instructions for removing the tweeter:
Is there a possibility to repair this tweeter, or is the solution always to replace it?
Is there a possibility to repair this tweeter, or is the solution always to replace it?
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You may only need to clean the magnetic gap or re-center the diaphragm to fix the problem.
If the diaphragm or coil is damaged, only the diaphragm needs to be replaced, but you should clean the gap before replacement.
Folded over masking tape can be used for cleaning.
If the gap is misaligned, (tape will drag at one point more than others) you will probably need to replace the whole tweeter.
does the problem disappear or change if you turn the speaker bottom up? Or lying on the back?
That could be sign of a sagging diaphragm/voice coil.
If so, you could try to mount the tweeter rotated 90 or 180° around its axis.
Isn't the dome/diaphragm glued to the tweeter? How can I clean under it? If I touch it, I am pretty sure it will be deformed.
I don't know if yours is glued or held in place mechanically.
Gaskets and surrounds can be sticky even without adhesives.
Scrape, tape, solvents, whatever is required.
Someone or something had to touch it to install it, it may have been deformed at that time.
The tiny piece of gasket touching the half roll surround, or the upper right gasket being too close could be causing the buzz.
Do a frequency sweep before and after removing that junk before any more dissection.
The odd cases of tweeter jumped out of its gap? I've had that twice on speakers now. How do you even have that happen? The amount of excursion required should never happen.
Maybe woofer pressure leaked in there?
Or person turned it up so loud the air heated up under the dome and in the coil chamber that it pressured the dome out? I might guess the latter, because it wouldn't come like that from factory, surely.
Maybe woofer pressure leaked in there?
Or person turned it up so loud the air heated up under the dome and in the coil chamber that it pressured the dome out? I might guess the latter, because it wouldn't come like that from factory, surely.
As for those cheap replacement domes. I have my doubts about them. They are all the same, regardless of suitable models, save for some variability in coil diameter - shiny "titanium", fabric surround, kapton former.
Many original domes use aluminium formers and diaphragm.
Many original domes use aluminium formers and diaphragm.
My joy was short-lived. The distortion is back. I spent the evening playing with the tweeter. There is voice coil rubbing. I tries to push it (from the periphery where it is plastic-ish just before the metal dome) in different directions while I was playing a tone. When the distortion was gone, as long as the tone continues, I get no distortion. But as soon as I stop it, the next time I play the tone, the distortion is back. Just like if it was going back to its "natural" position, except that now the natural position is rubbing.
When there is no signal, if I push down from one side (again as close to the dome as possible without touching it) it moves freely, but one the other side, there is some rubbing.
The dome is well glued to the assembly, so there is no easy way to lift it and clean, or reshape under the dome.
When there is no signal, if I push down from one side (again as close to the dome as possible without touching it) it moves freely, but one the other side, there is some rubbing.
The dome is well glued to the assembly, so there is no easy way to lift it and clean, or reshape under the dome.
What I've done before is to figure out where the coil/former is rubbing, then carefully scrape up the outer attachment of the surround (on the flange, alcohol and warmth can help soften glue), such that you can pull or shim under it and reglue it (EVA glue is fine) so that it no longer rubs. You kind of need some mechanical awareness to figure out if you need to lift a low point or pull across part of the surround. It may not be a perfectly symmetrical surround after it all, but it beats rubbing.
Sometimes the magnet has also shifted which is not always fun to re align, especially when you also have ferrofluid in the gap.
Sometimes the magnet has also shifted which is not always fun to re align, especially when you also have ferrofluid in the gap.
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That description makes it look like open heart surgery is simpler than this. I will have to gather myself and book a lot of focus time to try that out.
Did you try fx :
https://www.abitech.ca/
Veritas 2.X should be the "same" tweeter also, maybe different part.nr.
https://www.abitech.ca/
Veritas 2.X should be the "same" tweeter also, maybe different part.nr.
Thanks, I will do some soul searching and figure out if it is worth 200$ + shipping to save that speaker pair.