How the inside of a 20 yr. old Magnepan looks like

[jadis]

Around 2015, I heard some flapping in the bass of the R speaker and some mid range distortion on the L speaker. A friend immediately told me the wires have been detached from the diaphragm of the planars and I sought out an expert repairman who was very familiar with Magnepan speakers. I had to watch him 'undress' the 2.7s and it was quite a hell of job to do. Those tight cloth socks are fastened with countless staples below the frame. We carried it out to the garage and he cleaned them first, so much corrosion had built up in 2 decades, and the speakers were in a sealed air conditioned room with no windows for sunlight to hit them.



First time for me to see a 'nude' Maggie. And I saw the wires delaminated from the planar's diaphragm.





Above, we can now see the bass, mid and ribbon 'drivers', from left to right.



Corrosion all over the wires had to be cleaned with a special liquid. And a special glue had to be used to fasten the wires all over the panel.



There were no 'exotic' connectors or terminations used. The wires could even be ordinary hardware wires.

After the cleaning and the re-gluing (for about 3 hours), the speakers were pronounced ready to go again, but after a year, that black capacitor below died suddenly (loss of highs in the tweeter) and it took some online help from a user group member to help me diagnose the problem - ruling out fuse, connectors, wires, etc. It was a Solen 20uF cap and I had to buy a pair to change the other side as well. And here they are again today. singing in its 25th year from its day of manufacture. I



I should imagine the parts used in the recent 3.7i and 30.7 to be much much better.

 

[christoph]

Woah, that looks really bad
The words "faulty design" or "constructional defect" spring to my mind

Old Apogees had their own "issues" like crumbling foam that causes the dreaded "Apogee buzz" but I have never seen an old Apogee looking THAT bad
Let alone without sunlight and air condidioned

 

[microstrip]

Long time behavior of glues and foams was the Achiles knee of several speakers of the 70's. Although most speakers can be easily re-foamed with new surrounds, re-building panels is a more laborious operation . My otherwise perfect ELS63's need re-gluing of the stators - the perforated plates need to be glued to the frame. This operation will need the complete disassembly of the speaker and is a pain to carry. In this aspect the ESL57's were much intelligently designed, a 55 year old pair was recently still performing as new in my room after I replaced one leaky PCB of the HV supply.

 

[ack]

Phil,

I have to admit these are shocking pictures; my long-gone MG IIIa's must have looked the same, I assume. You may want to replace that yellow capacitor too, which looks like a Bennic, plus what looks like that blue electrolytic

 

[jadis]

Phil,

I have to admit these are shocking pictures; my long-gone MG IIIa's must have looked the same, I assume. You may want to replace that yellow capacitor too, which looks like a Bennic, plus what looks like that blue electrolytic

Tasos,

Yes.. The tech man told me to brace for the bad sight maybe due to our humidity all year long as he had seen some bad ones too. The more seasoned Maggie owners say the caps last really long and I will get there somehow. Right now the cloth is all sealed and it's tough to open it up again.

 

[DonH50]

Looks fairly typical to me, a little worse due to the humid environment (I assume). My MG-IIIa's were still going after 29 years until I retired them a couple of years ago (still have them). As a former tech I have re-glued many older Maggies (and replaced many ribbon tweeters). The latest versions use all QR panels IIRC so should hopefully be less susceptible to delamination.

Conventional speakers and ESLs aren't pretty after all that time, either.

 

[jadis]

Just to add, when the black Solen cap was diagnosed as the culprit, the tech man has on hand a pair of generic caps of the same value and I decided to put them on just to make the speakers work normally again while I order the original parts. I must say the sound of the generic cap sounds atrocious when compared to the Solen (when it arrived and was installed). There were many suggestions from user group members to use all kinds of cap brands, but again, I have been a bit reluctant to experiment with caps' 'sound'.

 

[christoph]

Looks fairly typical to me, a little worse due to the humid environment (I assume). My MG-IIIa's were still going after 29 years until I retired them a couple of years ago (still have them). As a former tech I have re-glued many older Maggies (and replaced many ribbon tweeters). The latest versions use all QR panels IIRC so should hopefully be less susceptible to delamination.

Conventional speakers and ESLs aren't pretty after all that time, either.

Phil said they were only used in an air conditioned room with no sun light.
This should be the perfect environment for the Speakers:
Because of the AC there is no humidity and because of the lack of sunlight, there is no Deterioration caused by UV Radiation.
Taking that into account, they look horrible

 

[jadis]

Sorry for the confusion, Christoph. What I should have said was the room has no windows and I turn on the air conditioning only when I listen. So most of the time actually the room at doing 30-33C about more than half of the year. Humidity ranges from 75-95% all year so perhaps the corrosion emanates from that.

 

[christoph]

Sorry for the confusion, Christoph. What I should have said was the room has no windows and I turn on the air conditioning only when I listen. So most of the time actually the room at doing 30-33C about more than half of the year. Humidity ranges from 75-95% all year so perhaps the corrosion emanates from that.

Looks like I misunderstood you completely
In this case the bad condition is totally understandable
Sorry for the confusion

 

[christoph]

Should I delete my postings above as they don't do justice to the poor Maggies under These circumstances?

 

[jadis]

Should I delete my postings above as they don't do justice to the poor Maggies under These circumstances?

No need, Christoph. No problem at all.

 

[christoph]

No need, Christoph. No problem at all.

Would be no Problem for me.
Just say yes and I will delete them...

 

[DonH50]

Air conditioning does not get rid of all humidity. Especially when starting from such a high point. In fact, as the AC is cycled, it can condense moisture out of the air onto other surfaces (like speakers, especially the cool metal wires in them).

IME humidity has little to do with delamination though it does increase the chance for corrosion (the green film). Sunlight and it's UV rays are death to both the glue and the panel material so again IME are bigger players in longevity. Smoke is also not a good thing (though a bigger issue for early ESLs). Back "in the day" it was my sad duty to tell folk that placing their panels against windows was not a good idea. The marketing answer was "why block those nice windows?" and the engineering answer was "why kill the life of your speakers?" Cone speakers are also sensitive to light but usually face away from the windows so less an issue.

Of course the biggest longevity issue is usually the guy with his (or her) hand on the volume knob...

 

[Folsom]

Woah, that looks really bad
The words "faulty design" or "constructional defect" spring to my mind

You're NUTS. For a high voltage device exposed to the air for 20 years, they look pretty damn good. And it all cleaned up nicely.

And Micro is right, glues have got way better.

 

[DonH50]

You're NUTS. For a high voltage device exposed to the air for 20 years, they look pretty damn good. And it all cleaned up nicely.

And Micro is right, glues have got way better.

Actually, they are not really HV devices like ESLs. But I agree with everything else.

 

[Folsom]

Oh right, that's MLs... I mix them up all the time because I don't care about either very much

 

[Don C]

My MG IIIa’s from 1987 are still sounding great in my home theater system today!
The example shown in this thread have been through a home rebuild hack job IMO.
They should have been sent back to White Bear Lake for a factory rebuild!

 

[Cycles2]

I just came across this article from @christof on the condition of the wiring inside his 20 year old Maggie 2.7s. I recently purchased pre-owned 20.7s that are circa 2016. Will I have to concern myself with similar issues in approx 15 years or has Magnepan changed the quality of the wiring?

 

[christoph]

I just came across this article from @christof on the condition of the wiring inside his 20 year old Maggie 2.7s. I recently purchased pre-owned 20.7s that are circa 2016. Will I have to concern myself with similar issues in approx 15 years or has Magnepan changed the quality of the wiring?

Please read the whole thread.

I was under the impression that those Maggies were stored in an AC'ed room but they were NOT...
This changes the picture dramatically