Radj from Jakarta, Indonesia

[Radj Jadoenathmisier]

Hi to all, I'm Radj from Indonesia. I'm new to Martin Logan owners forum, but have some experience to share.

One of the Clarity panels developed a crackling sound, buzzing at the beginning of startup. After playing music for 10-15 minutes, the crackling/ buzzing totally disappears and the panel functions as normal. I thought it might be one of the capacitors on the internal power supply, and tested them but found none faulted. I decided to swap "just the panels" from left speaker to right and concluded that it is the panel that has developed this fault, as the crackling/buzzing travelled with it. Inspected the panel more closely now, and the only thing I find different with the good functioning panel is that in the right bottom corner the Mylar sheet is showing wrinkled. Anyone having similar experience?

 

[amey01]

Hi to all, I'm Radj from Indonesia. I'm new to Martin Logan owners forum, but have some experience to share.

One of the Clarity panels developed a crackling sound, buzzing at the beginning of startup. After playing music for 10-15 minutes, the crackling/ buzzing totally disappears and the panel functions as normal. I thought it might be one of the capacitors on the internal power supply, and tested them but found none faulted. I decided to swap "just the panels" from left speaker to right and concluded that it is the panel that has developed this fault, as the crackling/buzzing travelled with it. Inspected the panel more closely now, and the only thing I find different with the good functioning panel is that in the right bottom corner the Mylar sheet is showing wrinkled. Anyone having similar experience?

I had this issue, but it was very soon after I bought mine and panels were exchanged under warranty. Didn't affect the sound though.

As your speakers are much older than warranty, I also heard at the time that some gentle heat can tighten the wrinkle. Search the forums and see what you can find, or contact ML for some direct advice.

Also, crackling and buzzing can mean dirt/impurities - so give them a good vacuum too.

 

[BigGuy]

May want to try vacuuming the panels as a first measure.

 

[Jazzman53]

The symptom you described is consistent with a loose area on the diaphragm flapping against a stator on start up, and then quieting down as as the diaphragm accumulates enough charge to locally stick itself to the stator.

If so; you should be able to audibly isolate the rattling sound to the wrinkled corner in question.

***********************
Assuming the wrinkled corner is the problem, there's a good chance you can resolve it by locally heat shrinking the diaphragm, using a heat gun blowing hot air thru the stator holes.

A heat gun can get hot enough to burn a hole in the diaphragm fairly quickly so you must use care to apply only enough heat to pull out the wrinkle.

A hair dryer might work if you hold it close on the area long enough (I haven't tried it so I don't know).

Note:
If the wrinkle resulted from the adhesive tape locally separating from the stator, the diaphragm would not then be anchored to the stator so heat shrinking may not resolve the problem in this case-- but only further pull the diaphragm away from the corner.

Heat shrinking is a risk as noted, but the problem won't resolve itself if you ignore it, and will likely get progressively worse, and the contact area would be increasingly at risk of arcing.

My guess is that heat shrinking the wrinkle out will resolve the problem.

 

[Radj Jadoenathmisier]

The symptom you described is consistent with a loose area on the diaphragm flapping against a stator on start up, and then quieting down as as the diaphragm accumulates enough charge to locally stick itself to the stator.

If so; you should be able to audibly isolate the rattling sound to the wrinkled corner in question.

***********************
Assuming the wrinkled corner is the problem, there's a good chance you can resolve it by locally heat shrinking the diaphragm, using a heat gun blowing hot air thru the stator holes.

A heat gun can get hot enough to burn a hole in the diaphragm fairly quickly so you must use care to apply only enough heat to pull out the wrinkle.

A hair dryer might work if you hold it close on the area long enough (I haven't tried it so I don't know).

Note:
If the wrinkle resulted from the adhesive tape locally separating from the stator, the diaphragm would not then be anchored to the stator so heat shrinking may not resolve the problem in this case-- but only further pull the diaphragm away from the corner.

Heat shrinking is a risk as noted, but the problem won't resolve itself if you ignore it, and will likely get progressively worse, and the contact area would be increasingly at risk of arcing.

My guess is that heat shrinking the wrinkle out will resolve the problem.

Thanks for your suggestions, very useful!

I isolated the crackling sound in the very old fashioned way, by using an empty kitchen paper roll core close to my ears and scanned around the panel. The crackling sound is actually not coming from the wrinkled corner as I initially thought/suspected, but from between the 4th and 5th section of the panel, counting from below. I do see dust/dirt accumulation between the 2 sections, which I am having difficulties removing by vacuuming(seems very sticky), see attachment. Any other way to clean that part of the panel?

 

[Jazzman53]

Thanks for your suggestions, very useful!

I isolated the crackling sound in the very old fashioned way, by using an empty kitchen paper roll core close to my ears and scanned around the panel. The crackling sound is actually not coming from the wrinkled corner as I initially thought/suspected, but from between the 4th and 5th section of the panel, counting from below. I do see dust/dirt accumulation between the 2 sections, which I am having difficulties removing by vacuuming(seems very sticky), see attachment. Any other way to clean that part of the panel?

Is the crackling sound coming from an area near or at the clear plastic diaphragm support (spar) ?

The question now is whether the crackling sound is mechanical (diaphragm flapping against a stator) or electrical arcing. If you don't see any associated movement of the diaphragm, then it's more likely to be arcing, which has a sharper "snap" sound with very fast rise-time.

If you compress that area with finger pressure against both stators, does that change or stop the crackling? If so, then it's a mechanical vibration (not arcing).

If you determine that the crackling is a mechanical vibration that goes away when you compress the area, perhaps we can figure out a remedy...

If compressing the area did not stop the crackling, then I suggest powering up the speaker in a darkened room and looking for visible arcing associated with the crackling sound, at the area in question.

If it's arcing, it would likely be at the spar edge where accumulated contamination creates a conduction path from the diaphragm to a stator.

If you've verified that the panel is arcing:
Since vacuuming your panels did not remove the sticky dirt you mentioned, I would first try blowing it out with canned air, and it that doesn't work, then spraying in some 90% isopropyl alcohol (IPA) and immediately blowing out with canned air. Use minimal solvent to avoid wetting adjacent area, and tip the panel such that gravity helps control where the solvent goes.

If IPA didn't dissolve and wash away the sticky contaminant, then a stronger solvent might. I would then try spraying in a small amount of acetone and blow out with canned air immediately. Acetone will soften the adhesive tape but only for a short while, as it's extremely volatile and flashes off very quickly.

Others have suggested using the shower cleaning routine but exposing the entire panel to water immersion would be a last resort for me-- for fear entrapped water corroding the copper foil charge strip that runs along the stator edge to conduct the biasing voltage onto the diaphragm.

 

[amey01]

Thanks for your suggestions, very useful!

I isolated the crackling sound in the very old fashioned way, by using an empty kitchen paper roll core close to my ears and scanned around the panel. The crackling sound is actually not coming from the wrinkled corner as I initially thought/suspected, but from between the 4th and 5th section of the panel, counting from below. I do see dust/dirt accumulation between the 2 sections, which I am having difficulties removing by vacuuming(seems very sticky), see attachment. Any other way to clean that part of the panel?

Have the panels been unplugged and unused for 24 hours before you vacuum? The charge will make the contaminant hard to dislodge.

 

[Radj Jadoenathmisier]

Is the crackling sound coming from an area near or at the clear plastic diaphragm support (spar) ?

The question now is whether the crackling sound is mechanical (diaphragm flapping against a stator) or electrical arcing. If you don't see any associated movement of the diaphragm, then it's more likely to be arcing, which has a sharper "snap" sound with very fast rise-time.

If you compress that area with finger pressure against both stators, does that change or stop the crackling? If so, then it's a mechanical vibration (not arcing).

If you determine that the crackling is a mechanical vibration that goes away when you compress the area, perhaps we can figure out a remedy...

If compressing the area did not stop the crackling, then I suggest powering up the speaker in a darkened room and looking for visible arcing associated with the crackling sound, at the area in question.

If it's arcing, it would likely be at the spar edge where accumulated contamination creates a conduction path from the diaphragm to a stator.

If you've verified that the panel is arcing:
Since vacuuming your panels did not remove the sticky dirt you mentioned, I would first try blowing it out with canned air, and it that doesn't work, then spraying in some 90% isopropyl alcohol (IPA) and immediately blowing out with canned air. Use minimal solvent to avoid wetting adjacent area, and tip the panel such that gravity helps control where the solvent goes.

If IPA didn't dissolve and wash away the sticky contaminant, then a stronger solvent might. I would then try spraying in a small amount of acetone and blow out with canned air immediately. Acetone will soften the adhesive tape but only for a short while, as it's extremely volatile and flashes off very quickly.

Others have suggested using the shower cleaning routine but exposing the entire panel to water immersion would be a last resort for me-- for fear entrapped water corroding the copper foil charge strip that runs along the stator edge to conduct the biasing voltage onto the diaphragm.

Many thanks for your suggestions. After spraying the sticky area with medical grade alcohol 70% and drying, the crackling noises totally disappeared. I attached a picture indicating the troublesome area between red lines, I was experiencing before spraying. Amazing, the Clarities sound great again!!

 

[Jazzman53]

Wow, that's great news!

The arcing would have eventually burned thru the stator's insulating coating so it's good that you resolved it quickly.

Frequent vacuuming will help prevent a recurrence.

Congrats on your success!

 

[Robert D]

Many thanks for your suggestions. After spraying the sticky area with medical grade alcohol 70% and drying, the crackling noises totally disappeared. I attached a picture indicating the troublesome area between red lines, I was experiencing before spraying. Amazing, the Clarities sound great again!!

That's awesome!

 

[Radj Jadoenathmisier]

Wow, that's great news!

The arcing would have eventually burned thru the stator's insulating coating so it's good that you resolved it quickly.

Frequent vacuuming will help prevent a recurrence.

Congrats on your success!

Thanks to your help/suggestions it's all sorted, amazing! How frequently would you recommend vacuuming? I purchased those Clarities around 12 year back and to be perfectly honest, only vacuumed the panel once with very reduced suction power, because I was afraid of damaging the panels...

 

[amey01]

Great news. Hopefully you've fixed it! Just monitor over a few weeks to make sure.

Thanks to your help/suggestions it's all sorted, amazing! How frequently would you recommend vacuuming? I purchased those Clarities around 12 year back and to be perfectly honest, only vacuumed the panel once with very reduced suction power, because I was afraid of damaging the panels...

I vacuum mine every few months. They are in a dedicated room though, so very little dust.

I use the bare nozzle with my hand cupped around the end, so that pressure builds up against the panel, and work my way over the panel, about 30 seconds each side.

Important though - make sure speakers are unplugged for 24h before vacuuming, so that the panel is completely discharged.

 

[Jazzman53]

Thanks to your help/suggestions it's all sorted, amazing! How frequently would you recommend vacuuming? I purchased those Clarities around 12 year back and to be perfectly honest, only vacuumed the panel once with very reduced suction power, because I was afraid of damaging the panels...

The diaphragms are not likely to be damaged by anything other than a point impact that punctures the film.

My original perf metal ESL's used ultra-thin 6-micron diaphragms, which I vacuum cleaned often, and even blew out with compressed air a few times, with no problems.

My latest ESLs have insulated wire stators with front & back magnetic grills which renders them practically immune to dust and arcing.

ML's are open and prone to dust buildup but the 12-micron diaphragms are pretty robust and protected by the stators so I wouldn't worry about vacuuming cleaning doing any damage. And of course; discharge the panels first, as described in the previous post.

How often to vacuum? There's very little risk so I'm thinking once a month.

 

[Robert D]

I think having an air cleaner in the room and/or house helps too. We have several HEPA filters running all day in the house along with an electrostatic cleaner on our heating and cooling system for the house. If you dont have one, pick up a HEPA filter for that room, and it will help keep dust down. This works well:

Honeywell HPA300 HEPA Air Purifier​

 

[Nuri58]

Even with all filters still dust - you can avoid it. But if you read ML's site, they give their advice on all this - worth reading I think