Proac Ribbon Tweeters Damaged


Hi all - this is my first submission, so looking forward to your responses...

I own 2.5 year old Proac D48 R speakers, powered by a Parasound Halo A21 amp (about 8 years old). When listening the other day I thought the speakers sounded dull, muddy. It appears both of my ribbon tweeters have gone out and I am at a loss to understand why.  The amp is certainly not under powered to cause clipping damage and I never play my unit abnormally loud  - maybe 1/4 to 1/3 total volume.

As you can imagine, my repair/driver replacement will not be covered by warranty as this is not considered a manufacturer defect. I am told the tweeters run $399 per.

Worst thing I can do is have these repaired and then have it happen again. HELP!
gnoworyta
Forgot to mention - no vacuuming of the tweeters. I am very careful with my equipment - that's why this is so frustrating.
gnoworyta, no matter how this sounds I am just trying to be helpful. I realize you are trying to find the cause of your problem, not repair of the tweeter. I was just looking online and it seems the most common problem with ribbon tweeters is that the tweeter material, which appears made of an aluminum foil type material, rips. From what I read, if your problem is a ripped ribbon, it appears to be an easy fix for a professional, assuming it is not an exotic material.  Is it possible to visually inspect if it is ripped?  Also, if you can remove it from the speaker maybe you can isolate if it works ruling out a crossover issue.  I hope some of the guru's here can help out on how to test a ribbon speaker detached from the speaker cabinet.

Here is a YT of a RAAL being repaired. https://www.youtube.com/watch?v=bvylZF9eJOA

It may be your dealer knows that something else is burned out within your tweeter making it totally unrepairable. Like maybe a ripped ribbon tweeter still makes some noise, or whatever, and your doesn’t. But if your saying its $800 bucks for a new pair I would definitely investigate further. Millersound is first rate, give them a call. When my woofers needed repair he basically said he can repair most anything on the woofer regardless of problem.
jetter - appreciate any and all advice/comments.

My Proac dealer is supposed to be coming by this week to take a look at my speakers. I have no idea as to his level of expertise in regard to analysis/repair, so we shall see...

In the meantime, I welcome all input.
Regarding the possibility that the root cause of the problem may have been the speakers themselves, here are some excerpts from the following thread, although it is about a different Proac model:

https://forum.audiogon.com/discussions/proac-problem-tweeters-or-crossover

Audioconnection 3-10-2015

Having sold Proacs for 24 years
It could be a simple fix.
Unscrew and remove both top tweeter section knurled binding post nobs.
Insert carefully a small blade screwdriver into the hole and gently tighten the top binding posts clockwise a half turn till snug if its still loose go for another half turn but do not over tighten.
If this seems to get back your volume you are set.
If its still intermittent removing the woofer and get into the crossover board connection area and clean up the star washer x over board area where the binding posts meets the board will complete this.
Hope this works for you
JohnnyR


PBNAudio 3-16-2015

Jonny R from audio connection gives some good advise on terminals however don’t tighten them from the outside, open them up and tighten the nuts on the inside. Proac use Mitchell binding posts they have a knurled shaft you don’t want to loose the grip they have in the mdf plate that they are mounted in.


CTSooner 3-17-2015

PNB, that’s also great advice. I have had to do that with a few different Proacs that either I owned or my friends have owned. Wish that was fixed by them in the 90’s when they first encountered the problem.


Perhaps over time internal vibrations have caused a connection to loosen. And if that occurred at slightly different times in the two speakers, is it possible that it wasn’t noticed until the tweeters in both speakers stopped working?

Hope that helps. Regards,
-- Al

Tweeters in general are delicate and amplifier clipping can easily burn them up. Ribbon tweeters are in general the least robust type of tweeter. They are what I would call “rather fragile”. A large pop or click from switching inputs could have done them both in.