EMIM sparks

[mimo_proshol]

Hi, everybody
I wonder, if anyone have seen that or have any explanations of "lightings" in the EMIM driver?
This is the story
I've recently upgraded to Infinity IRS Omega. What a lovely speakers!!! But after some initial euphorea calmed down a bit, I've started to test them throughout. On one Netrebko record(recorded at a very high level pure soprano voice) I've noticed sparks whithin, or behind the EMIM driver! Shock! But the sparks are seen only when this record was plaid! When the sparks are seen, there is some distortion. No distortion or sparks on other records.
The amp is Gryphon Callisto 2200 some 400W per channel @ 4 Ohm shows no sighns of weackness.
A "beard" of magnetic particles stuck to the EMIM magnet is pretty large, bigger then the "healthy" driver's.
Your advice is needed!

 

[petehall347]

was thinking they might have light bulbs fitted for safety but that wouldn't explain the debris .

 

[dcmaster]

Hi mimo_proshol,

sparks are a sign of too much current or voltage! That is a very borderline situation and you should definitely be careful! If even lightning can be seen, the Emim is nearing death by overload!

The cd has apparently extremely high level, which can destroy the Emim definitely. If you want to keep alive the Emim, you should urgently drive the music with lower level at this level of this recording.

Klaus

 

[slimpikkins]

I'm guessing the diaphragm is being stressed or slightly torn so that it is touching the magnets and shorting itself out on that track. I have no experience with that emim. Many emims have pieces of non conductive tape on the magnets so that can't happen. Maybe someone else has experienced the same. You may be able to put some skinny pieces of tape on those magnets but then you will need to shim out them what ever the thickness of the tape is....again only guessing.
Jim

 

[slimpikkins]

Hi mimo_proshol,

sparks are a sign of too much current or voltage! That is a very borderline situation and you should definitely be careful! If even lightning can be seen, the Emim is nearing death by overload!

The cd has apparently extremely high level, which can destroy the Emim definitely. If you want to keep alive the Emim, you should urgently drive the music with lower level at this level of this recording.

Klaus

There you go, dcmaster posted this at the same time I posted my reply. I would trust his advice over mine any day!
Jim

 

[jmduc]

EMIM diaphragms will sometime " wrinkle" and appear wavy causing the arching. I have repaired a few by using a hair dryer and carefully heating the diaphragm till the mylar stretches and straightens the the foil. Be careful with the amount of heat and use a dryer with variable heat,don"t start to close to the diaphragm. Also check all the EMIMs.

 

[okeeteekid]

The high energy emim's backings are made of kapton, if you are seeing sparks then there is either a short somewhere in the traces, could be wrinkles possibly touching the magnets or the diaphragm could be wavy touching the magnets, if it is wavy it can be loosened carefully at the top and reinstalled to get the wave out, it can also be a tear in part of the trace or there could be a metal particle or even a strand of copper wire in it shorting it out, it could also be the black coated copper wire that connects... if i remember correctly, the negative terminal to the traces has come loose, ( the wire can only be seen when you take the driver apart ) if i were you i would try playing some piano music to see if you can hear any distortion or scraping of the diaphragm to the magnets or a loose wire, i have worked on many of the high energy emims you need a jig to disassemble them without damaging them, without taking it apart you really won't know if there is anything wrong with it, congrats on getting your omega's they are nice speakers, where did you find them?

 

[mimo_proshol]

I'm trying to obtain maximum info before starting this risky disassembling-assembling procedure.
Are the metal traces on the diaphragm isolated on the back side? If not, then is it possible, that the sparks appear when the bare metal traces touches not the actual magnet, but the "magnet beard" I've mentioned above?

 

[okeeteekid]

The aluminum that you see from the front are the metal traces or coil, I don't know what you mean by "magnet beard" can you take some pictures of the front of the emim and post them here so we can see what the so called "magnet beard" that you are talking about is.

 

[slimpikkins]

A "beard" of magnetic particles stuck to the EMIM magnet is pretty large, bigger then the "healthy" driver's.
Your advice is needed!

Looks like this is what he means and it can't be a good sign.

 

[okeeteekid]

Looks like this is what he means and it can't be a good sign.

If that is what he means then it's definitely not a good sign, the particles would have to be removed and the best way to do it would be to disassemble the driver so that you do not damage the diaphragm while trying to remove the particles, i would still like to see some pictures of the emim.

 

[Ken Boyd]

Don't some of the EMIT's and EMIM's have a problem with some flaking of the magnet? Could be pieces of small magnetic dust from that flaking making a beard of particals and those particals are being piled up in an area and then the traces are touching them when the diaphram is being driven hard, just a guess really.

I have quite a few recordings of that opera singer and I have never seen any sparks from any of my EMIM's, but if anyone can get a spark from a pair of speakers she certianly has the ablity!

 

[audiomagnate]

The nickle plating on the Emims flake off, and if they touch the traces on the diaphragm, watch out. Here is a picture of a flaky one I just acquired. It fails the piano test miserably, but I just bought it for the diaphragm, so that's OK. BTW, the Emim magnets in my 2.5s look brand new, so I believe this deterioration might be climate related. We're high and dry up here, which lets foams, and maybe Emim magnets last longer. A magnet replacement mod kit is available on that auction sight. Don't take apart your EMIMs without a jig!

 

[par4golf]

Sparking

I once saw sparking coming from an emit when I was auditioning a pair of RS5's at Bryn Mawr Stereo in Moorestown, NJ. Seemed the salesman was just a little too anxious to demo them to me, after the sparking incident, I held my ear to the emit and it was DEAD!:tears:

 

[okeeteekid]

The nickle plating on the Emims flake off, and if they touch the traces on the diaphragm, watch out. Here is a picture of a flaky one I just acquired. It fails the piano test miserably, but I just bought it for the diaphragm, so that's OK. BTW, the Emim magnets in my 2.5s look brand new, so I believe this deterioration might be climate related. We're high and dry up here, which lets foams, and maybe Emim magnets last longer. A magnet replacement mod kit is available on that auction sight. Don't take apart your EMIMs without a jig!

The coatings on the newer high energy emim's are non conductive, i just tested for it with an ohm meter, the coating looks to be either a black paint or black epoxy, they look much different than the older style emim's that have the nickel coated magnets.

 

[audiomagnate]

Has anybody ever attempted to clean the peeling nickle plating off, and use them that way? Is the nickle there for any reason except to make them look all shiny and nice? I'm thinking a magnet is still a magnet and should function without the plating, which I'm guessing was plated for cosmetic reasons.

 

[mimo_proshol]

I've examened my EMIM more thoroghly. It seems that the magnet is nickel coated and this coating is flaking! So the bare coil (I discovered that it's not isolated on the front side) may touch the metal flakes which may couse sparks.
What should be done about it? I see, that disassembling is inevitable. The flakes should be removed. Should the magnet be painted or something, or just cleaned and left as is?
Your advices are highly appreciated!

 

[okeeteekid]

I've examened my EMIM more thoroghly. It seems that the magnet is nickel coated and this coating is flaking! So the bare coil (I discovered that it's not isolated on the front side) may touch the metal flakes which may couse sparks.
What should be done about it? I see, that disassembling is inevitable. The flakes should be removed. Should the magnet be painted or something, or just cleaned and left as is?
Your advices are highly appreciated!

That's weird that harman would use the older style nickle coated magnets in the omega, here is what the magnets look like from an irs epsilon, they are black epoxy coated, i had the ren 90's/80's and sigma and all their magnets were always the black epoxy coated type, the black magnets never peel, in fact i have had a couple of these magnets in my damp garage for years and they still look like new, the omega was the last speaker harman made that uses the HE emim's... i wonder why they decided to change the magnets to nickle coated, here is a pic of the magnets used in the epsilon/sigma/ren 90/80, you can take your emim's apart and scrape off all the loose coatings and then coat the magnets with super glue and then paint them but how long will that last as the nickle coating that is not loose now will probably start peeling again in the future, you need a jig to take them apart, without a jig they will get damaged..

 

[audiomagnate]

That's weird that harman would use the older style nickle coated magnets in the omega, here is what the magnets look like from an irs epsilon, they are black epoxy coated, i had the ren 90's/80's and sigma and all their magnets were always the black epoxy coated type, the black magnets never peel, in fact i have had a couple of these magnets in my damp garage for years and they still look like new, the omega was the last speaker harman made that uses the HE emim's... i wonder why they decided to change the magnets to nickle coated, here is a pic of the magnets used in the epsilon/sigma/ren 90/80, you can take your emim's apart and scrape off all the loose coatings and then coat the magnets with super glue and then paint them but how long will that last as the nickle coating that is not loose now will probably start peeling again in the future, you need a jig to take them apart, without a jig they will get damaged..

Why do you need to coat them with anything after removing the nickel plating, and how do you know the newer ones use Epoxy? I've got some flaky EMIMs I'm going to work on tomorrow.

 

[okeeteekid]

Why do you need to coat them with anything after removing the nickel plating, and how do you know the newer ones use Epoxy? I've got some flaky EMIMs I'm going to work on tomorrow.

Here is what the newer magnets look like, see the attached pic, I have owned all the speakers but the omega that use the newer high energy emim mid range drivers, IRS epsilon, ren 90/80 and IRS sigma and i have disassembled and worked on many of the newer HE emim's, the HE emim's magnets are coated with either a black epoxy or black lacquer paint from what i heard, i did a test on them and scraped off all of the coating so that the magnet was bare, i actually broke one in half to better expose the magnet then i placed them on the floor in my damp garage for two years and after two years was up they looked the same as they did from day one so i know they are high quality magnets, who knows they may even be samarium cobalt because they held up so well in my test, if i did the same test with known neo magnets they would have been a mess, as for the nickle coated neo magnets used in the older style emim's, neo magnets have to be coated with something to prevent oxidation, just google search neodymium magnets to read how they easily oxidise, that's the down side of using neo magnets, they are strong, cheap to produce but they oxidise/corrode easily, the old style emim's are coated with nickle, if the nickle coating starts to peel the magnet will start to oxidise because they no longer will be sealed from the elements , once they start to oxidise/corrode they crumble apart and loose their shape, i stored slot cars in my garage that have the nickle coated neo magnets and all of their magnets have eroded away to the point that the magnets literally crumbled apart to nothing, so if your magnets are peeling you better re seal them before its to late.