Please indulge me for a minute whilst I try and explain my thoughts and ideas -
I have a set of Carver originals with the Plat 60" ribbon upgrade.
I bought them in January, one side buzzed, and now, in the warmer weather of Summer, both sides buzz like a kazoo.
I've investigated as many options as I can think of to overcome these problems, including of course the hair dryer technique and tensioning bolts around the area of buzz.
I've had ads running on Craigslist, Agon, Circle and Asylum, and of course this site too, but it hasn't resulted in a replacement/fix.
I purchased a used unit on eBay for over $500 and it arrived in pieces - dislodged magnets and a torn ribbon. That experience has put me off anything which involves shipping, including the option of having the ribbons professionally rebuilt by the operator of this website. I've tried to justify driving these to Florida myself and waiting for the rebuild, then driving them back. Or, shipping them down, and driving down a week later to pick them up. But it's a haul from Green Bay WI and I can't fit it into my schedule (nor justify the costs)
So I'm looking at the ribbons with a hammer in one hand and a screwdriver in the other, intent on mischief. (there's little to lose at this point).
So, what I'm thinking of, and what I'd appreciate some guidance with, is coming up with a way to add tension to the ribbon, in the way in which you might tension a guitar string. Obviously not via a rotational tension but via some lateral tension.
I haven't opened them up, nor have I removed them at this point from the speaker, so I'm basically reconnoitering a potential fix and looking for advice.
I see that protruding from the ends of the ribbon enclosure are what looks like a PCB, with 3 nuts/bolts fastening it to the ribbon assembly. I'm assuming that the ribbon foil is attached in some way to that PCB.
What I'm considering is this -
Remove the units from the frames and set them on the bench.
Loosen off all the screws which hold the magnets in place, not so they're completely loose, but essentially un-tensioned.
Loosen off the 3 bolts on the ends of each PCB.
Try to prize the PCB away from the ribbon enclosure, gently, ensuring it isn't broken. There looks to be some kind of adhesive in use, so I guess I'm just trying to break the bond of that adhesive so the PCB's are somewhat free to move. Since the magnet bolts won't be completely loosened, there won't be much 'lift' between the PCB and the ribbon assembly frame in which to free the bond. So maybe I can insert something like a spark-plug feeler gauge between the PCB and the frame, to try and break the adhesive bond???
Then, clamp the ribbon assembly firmly to the bench.
Then, attach small clamps to the protruding part of the circuit boards, being careful not to crack the boards by loading them vertically. I'd need to make some kind of jig or support for the clamps.
Then, basically tension the clamps outwards from the ends of the ribbon assembly so they're pulling on the ribbon, like a guitar string. Of course, I wouldn't apply much tension, just enough to perhaps result in a 0.5mm of movement, or less.
Then, with the clamps still under tension, re-tighten the bolts holding the PCB and retighten all the magnet bolts.
My theory is that that would then clamp the retensioned ribbon firmly in situ.
So I guess what I need is for someone whose actually opened one of these things up to point out the folly in my assessment.
is it feasible, if conducted under a very careful and controlled environment, or is there something physically preventing this method from working?
My main concern is that the PCB is bonded to the assembly and that it won't move sufficiently to tension the ribbon.
Though I'm assuming that when these units are assembled from new, there was some tension applied via a similar process, albeit without the magnets in place, perhaps.
Any thoughts, suggestions would be appreciated. Again, at this juncture there isn't a whole lot to lose other than my time. And I'd prefer not to waste that if people think this is destined to fail.
If that's the case, can anyone make any other suggestions which haven't been explored around here?
One last point -
The left side ribbon worked flawlessly when I bought this during the Winter. Now, in the warmer, humid weather, it actually buzzes worse than the other side.
My concern and question is - do newly rebuilt ribbons work without ANY buzz, or is there a tendency for some to buzz even after a rebuild. In other words, is this buzz issue inherent in the design?
Thanks for any feedback/comments/ideas etc