Martin logan repair

[4RUNNER 524]

Morjet  your inbox is full

[Chops 694]

Just curious, what's wrong with your ML?

[4RUNNER 524]

One panel is failing its about half volume. Have switched panel to other cabinet to confirm the panel is failing.

[jazzman53 1,300]

Assuming there is no buzzing noises (loose diaphragm) only two faults can lower the panel's output:

1)  Degraded diaphragm coating (resistance too high; hence, reduced biasing charge on the diaphragm)

2)  Degraded connection where the bias supply wire contacts the diaphragm (reduced biasing charge on the diaphragm).

 

Some ML panels have the horizontal spars (diaphragm supports) bonded to both stators.  These panels cannot disassembled without destroying the diaphragm.  Repair in this case would involve replacing the diaphragm... it's do-able. 

 

Some ML panels have the horizontal spars bonded to the rear stator only.  These panels can be disassembled leaving the diaphragm intact.  In which case, it would be possible to re-coat the diaphragm (one coat Licron Crystal ESD) and/or restore a faulty connection to the bias supply wire (over coat connection with conductive paint available from auto supply stores -- typically used to repair rear window defroster grids).    

 

 

[morjet 30]

Mail box is now good. The Arious can be opened up and recoated. I would remove the panels and swap them around making sure to check all the connections. Then see if the panel is down on sound or it's something in the speaker cabinet. If it is the panel I can give you instructions on recoating the panels, & what products to use. Easy but time consuming delicate work and very well worth it!

Ed

[morjet 30]

And do NOT wash Martin Logan panels. We get so many panels that have previously been washed in the shower and it corrodes the copper conductor that feeds the mylar causing reduced sound over time as the corrosion spreads. Vacuum every few months is best.

[jazzman53 1,300]

And do NOT wash Martin Logan panels. We get so many panels that have previously been washed in the shower and it corrodes the copper conductor that feeds the mylar causing reduced sound over time as the corrosion spreads. Vacuum every few months is best.

 

 

Good point about NOT washing the panels, Ed.  I cringe every time I read that somewhere.  

I don't know much about ML panels but I recall seeing a video made at the ML factory where a technician merely taped in place the bias supply wire on the bottom edge of the diaphragm.  And then I've seen photos of other panels disassembled where ML used a copper foil charge strip.  I use a full periphery copper foil charge ring on all my DIY panels.  

 

BTW, just wondering what you would use to re-coat a diaphragm.  Licron Crystal works really well but it's not perfectly clear and it's a bit pricey so I'm always on the lookout for something better.  I'm not sure what ML uses but I figured it's probably an indium tin oxide coating.  

 

Thanks,

Charlie 

[morjet 30]

i would love to see some of your projects. Right now we are working on a cylindrical esl panel. Hope to get it done sometime this summer.

For home use nothing is easier than licron crystal. It is best to buy in the gallon and use an automotive paint spray gun to apply. If you use the licron spray can then after you spray a coat on the mylar then use a sponge hobby / paint brush to smooth it out immediately after you spray the coat on (one stroke all the way across) then it is relatively clear. Depending on if It's a recoat or new mylar 1 or 2 coats works best using that method. The only draw back with licron is a touch of harshness at very high volumes in the upper spectrum.

Ed

[jazzman53 1,300]

i would love to see some of your projects. Right now we are working on a cylindrical esl panel. Hope to get it done sometime this summer.
For home use nothing is easier than licron crystal. It is best to buy in the gallon and use an automotive paint spray gun to apply. If you use the licron spray can then after you spray a coat on the mylar then use a sponge hobby / paint brush to smooth it out immediately after you spray the coat on (one stroke all the way across) then it is relatively clear. Depending on if It's a recoat or new mylar 1 or 2 coats works best using that method. The only draw back with licron is a touch of harshness at very high volumes in the upper spectrum.
Ed

 

I would be interested to see your cylindrical design.  I assume the back wave vents thru the top of the cylinder?  Thanks for the tip on the Licron technique.  

 

I've built mostly perf metal flat panel ESL's but but my latest project is a tailored dispersion hybrid ESL with electrically segmented copper wire stators.  They were well received at last year's Carverfest-- I'm pretty happy with them and not planning anything new right now.  

 

My website HERE describes several of my projects with build photos.    

[Chops 694]

 

 

I've built mostly perf metal flat panel ESL's but but my latest project is a tailored dispersion hybrid ESL with electrically segmented copper wire stators.  They were well received at last year's Carverfest-- I'm pretty happy with them and not planning anything new right now.  

 

My website HERE describes several of my projects with build photos.    

 

I just read through your build page. I would love to hear how your ESL's compare to my ML SL3's.

 

I wish I had the skills, tools and space to do a build like that. Possibly even a full range panel (or at least near full range). 

[morjet 30]

Wow Jazzman you are an artist, and engineer. That is quite the gorgeous speaker. I would love to hear what comes out of them someday. Thank you for sharing!

And SL3 are no slouch. They are one of my favorites in the ML line. I normally always have a pair albeit modded a bit.