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
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.
almarge - thank you

shadorneb- thanks. Scary to think they are that delicate. That said, I don't recall doing anything recently in operating my set up that I have not done over the course of the last 2.5 years, in which the speakers were fine.
Growing up we had a large with room with McIntosh gear and a pair of ADS 910 speakers.  When I played music too loud, with the loudness or the bass up too high on the C28 preamp, the 910 tweeter fuse would blow.  Looking back, my father was quite patient with me.  In true audiophile form, he always asked if I could notice that the highs were absent, rather than get angry about the fuse.  
Do you have kids in the house?