Panel rebuild guide?

[Robert D]

I was able to sell my Theater i for about $650 if I remember right. Definitely made sense to me to sell. I used that toward the $3000 for a new Focus.

 

[birdbox]

That sounds like a winner idea!

Once you know the deflection you can tension the diaphragm to the same deflection to yield the same tension that ML applied. It's better to over-tension rather than under-tension the diaphragm so you want to err on the high side. Also; before tensioning the diaphragm, add some reference marks on the film using a fine tip felt pen.

Then, after the film is tensioned to the determined deflection, you can measure the distance between reference marks (post stretch) to determine the percentage of elongation, and the elongation is the what you would specify in your rebuild guide.

Others could then use your guide to tension their diaphragm using the same thickness of film and stretching it to the specified elongation, which is easy to measure with reference marks and a ruler.
For example; if the elongation is 1%, you would place reference marks 12" apart and then stretch the film until reference marks were 1% farther apart (12 1/8" in this case).

Based on ML lack of any support for the Theater center channel speakers there will likely be a market for a refurbishing service. I don't think I'm that person, however, I'd be willing to inquire some details of how to diy directly from ML if they are willing to play ball since they won't take on the responsibility themselves. I suspect there's a decent market for this with most of these speakers at 20+ years old by this point.

This could be a means for an experienced diy-er to find a niche market and make a few bucks on the side. I'm probably not that person having zero experience with electrostatic builds/refurbishment, but based on Jazz mans input, it seems like something that can be done and with practice attain results nearing 100% equivalent of a new panel. The centers have a lot of double sided tape that needs to be studied for geometry, material, and purpose/intent. The means to attain appropriate "tension" would also need some study and guidance, preferably directly from ML design "drawings". A method to safely disassemble an old panel without ruining the parts needed in the rebuild would also be necessary.

If we could get a few old panels that have already been replaced back when ML still supported replacements, that would be the key to figure this out as it'll take a couple of iterations at a minimum to work out the kinks (figuratively and literally).

Again, I'm not the right person for the job, however I do think a team of a half dozen people bringing resources and knowledge together could achieve the intent, which would be to develop a process and tools to rebuild ML centers no longer supported by the company.

Now, the hard part....finding someone who's willing to take this on and lead the effort. It's no small task.

 

[Jazzman53]

Thin stators could easily be damaged (bent) by prying them apart. But if the panel is dead anyway, there is little to lose.

Rather than prying the stators apart, I would attempt to saw thru the adhesive bond lines using 80-pound braided fishing line strung on a bow. I would start at a corner and saw perpendicular to the curvature.

If the panel edge-spacer/adhesive is urethane foam tape only, a string saw will cut thru that easily.

In addition to whatever type of edge spacers are used, I see in photos of the Theater panel [at least] two clear plastic horizontal spars in the center of the panel. These bond lines are no doubt a clear non-foam adhesive tape that would be not as easy to cut thru with a string, but since they are not very wide, perhaps it's do-able.

If the panel edge-spacers/adhesives are hard shims sandwiched between non-foam type adhesive tapes, those bond lines would be about 1" wide and difficult to cut with a string saw, but perhaps do-able.

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Since I stuck my foot in my mouth by starting this thread;

If someone wants to send me a Theater panel, I will attempt to disassemble and rebuild it, and document the process. Just PM me.

If the rebuild is not successful (i.e. damaged stators or panel doesn't play at full volume after rebuild) there will be no charge other than shipping.

If the rebuild is successful (i.e. panel plays at full volume), the owner agrees to reimburse actual cost for the materials used, plus return shipping. If the required materials happen to be materials that I already have on-hand (6-micron Mylar, 1/16" foam tape, Licron Crystal ESD coating) I would donate those at no cost.

There would be no charge for my labor in any case-- call it my contribution to the cause.

I have no desire to go into business rebuilding panels, so I will only agree to rebuild one Theater panel, and post the results.