just like to share my findings about buzzing apogees. I owned stage, duetta 1 and now signature.
Duetta 1 was heavily buzzing, also the signature (in less stronger way). Sooner or later all older apogees will start to buzz. The foam will degrade, no exception.
Of course, providing new graz bass ribbons is the top of the cake, but what to do, if your financial situation doesn't allow to spend this money?
I found a nice working solution, to get them absolutely buzz-free, without degrading overall performance. It even improves quality in bass or brings them back to near factory state.
The magic here is sillicone, mixed out of 2 components. I got mine from http://www.marronnier.de/. I used Zhermack HT33 (2 components) and silicon oil to make it very soft.
Secret is, to apply only very few sillicone on the foam at the frontside of the bass-panel. It's enough to give back the flexibility to the foam ( the silicon flows into the foam, stays there and supports the cellular structure of it)
One have to experiment with the amount of the silicone oil; It defines the resulting hardness (shore factor) of dried silicon.
It must be very soft, to give back damping function to the foam. I used 1 part hardener (component A), 1 part silicon (component B) and 1/2 parts silicon oil.
I used around 12 ml per foam-rail. Drying is over after 5 hours.
I applied it with a shot (right word ?) The stuff to do injections, like doctors uses.
At the top of the shot, I attached a small, 8 cm long tube, to place the silicone more exactly.
If your apogee is still buzzing after this procedure (my old duetta 1 did this), you can repeat this with the backside of the bass-foil. Here it's a little tricky, 'cause you can't reach the foam directly. The solution here is to use the openings at the top and let the silicone flow down the inside. You have to place the speaker that way, that the gravity keeps the flowing silicone on the foam and enables it to flow slowly down.
My old duetta 1 sounded wonderful after this procedure. I only tuned the resonance peaks after siliconing (be very careful not to tighten the screws too much. the foil is fragile).
The buzzing is absolutely gone.
Now I own signatures and they too buzzed, but not so strong like the duetta 1. I applied the same method here, except I used fewer silicone and put it only on the front side, not the back.
Here too; Siliconing, tuning bass peaks and I've got a perfect speaker.

Feel free to ask.

Olafzen

Interesting post , and i believe lots of owners do not have the resources to replace with new ribbons or to ship them to the installer.
My question is how do you tune the bass ribbon afterwards ?
onlly by your ears or you did it like in the manual with all the electronic instrument's?

I've got a calibrated measuring mike and on pc I use arta (http://www.fesb.hr/~mateljan/arta/) fine tool, btw.
I set resolution to 1/24 dB so I clearly see the single peaks. I act like described in the PDF you find on the apogee site.
I can show pics, but it's nothing interesting to see, because the silicon disappears inside the foam, so it looks like original (only slightly shimmering of the foam due the silicon).
I don't think you can tune by ear, the single peaks are too close near each other to vary.
Beside all the tuning; You can't get rid of the excessive bass resonance, in my room it's a strong 30 Hz peak around 12 dB high. I use digital equalization for it.
But I guess it's personal taste to tame the resonance or not. It too depends on room size.
Hope that infos help.

Olafzen

Your successful experiment, if it works on my Scintillas, is a God send. Thank you very much.

I wish you good luck.
Please, if you'll do the procedure: Report your results back in this forum.
And of course; Feel free to ask.

Respectfully - I would like to go on record and suggest these "alternative repairs" suggested by some this week show a deficiency of understanding of how buzz originates and manifests itself. Whilst I realise I will be accused of "defending my profession" I would suggest owners should think carefully before mutilating their speakers in search of the cheap/free solution. Owners should be aware that damping foam is both under and over the ribbons of all Apogee bass ribbons, and that the vertical and slant clamps are glued under and over the ribbon to form a firm connection , tampering will kill the ribbon - assured.

Accurate "foam revival" is not a new thing actually, and has been disproven several times over the years.

Buzz frequencies tend to be in the range 140-280 cycles, well above the tuning range of the bass ribbons. For more understanding of buzz;-

http://www.audioworld.com/sw/Forum1/HTML/003707.html

To artm1:

locating the buzz is difficult, so I use silicone along the complete foam line.
Try first the front-side, maybe it's enough to kill the buzz.This Silicone has very strong adhesive powers, so it "grips" the foil even if applied on only one side.
So try first at the front side, maybe it's already enough.
If you apply it the on the backside, pour it very slowly out of the shot on the visible part of the foam, you'll see how it flows into the foam. Very slowly it creeps down to the bottom. You must be patient and pour really slow out of the shot. Take a good quality shot with a stamp inside of rubber, with cheap shots, you can't push evenly enough.

To Graz:
Understanding the buzz is no rocket science. It's simply touching of the foil against the wooden frame resulting in a kazoo like sound.
Giving back the foam it's elasticity prevents this to happen.
And nobody (at least I don't know about it)
wrote exactly and suggested this special soft silicone and this way of applying.
Taking ordinary silicone (this stuff for showers, bath, etc.) is not so good. It becomes too hard when dried and you can apply it better with a shot, than with this big tubes.

So what's the problem; If one can afford, or is willing to use your foils she/he will do anyway.
If not, what's the alternative: Living with a buzzing apogee, bring it to the waste dump?
Why not trying to use the method mentioned here, there's nothing to loose if you work exactly.
And this you can believe: my Duetta didn't gave me fun with a lot music, and I don't listen only to music with little girls and guitars, I very much like bass.
Applying the silicone cured them, believe me.
You can question my ability to tell right from wrong, it's up to you.
I know what I did and I can hear.

So long

Olafzen

edit: My ribbons aren't killed by this procedure. Quite the contrary: vibrating against the wooden frame surely isn't good for the ribbon. Now the silicone prevents this.

edit 2 :-) @ artm1: watch at the bottom of the speaker, at one point, you see the silicone arriving there. So it flows all the way down. Don't forget to place the speaker all the time that way, that gravity keeps the flow on/ in the foam. If you use the silicone oil, the mixture is quite liquid when not dried.

[This message has been edited by olafzen (edited January 11, 2009).]

1. Really, for the back side, how can you see the silicone flowing through the foam?

Frankly, I would be scared to try it on the back as there's apparently little control of flow. Of course, if it worked for you then that's hopeful. Did you actually do it on the rear?

2. As for the front, do you position the speaker vertically or horizontally?

3. How long has it been since you've done this? Have you run a signal generator to test for buzz?

muralman1- Go here for translation:

http://babelfish.yahoo.com/tran slate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http%3A%2F%2Fwww.marronnier.de%2F&lp=de_en&btnTrUrl=Translate

...and here for the actual product:

[URL=http://babelfish.yahoo.com/translate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http%3A%2F%2Fwww.marronnier.de%2Fshop7%2Fadvanced_search_result.php%3FXTCsid%3D3223e8282c4db5 ]http://babelfish.yahoo.com/translate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http%3A%2F%2Fwww.marronnier.de%2Fshop7%2Fadvanced_search_result.php%3FXTCsid%3D3223e8282c4db5[/UR L] fb2ce1c23db6aa3089%26keywords%3Dht33%26x%3D0%26y%3D0&lp=de_en&btnTrUrl=Translate

*** Enter the entire URL on the 2 lines. Apparently the board software is too stupid to parse two lines! ***

go to the mentioned site, click on "weiter in den Shop", type in the search field at the top "Zhermack ZA13 KIT, 1 kg".
This will bring you to the silicone and hardener (two small bottles).
You further need the silicone-oil. You'll find it on their site, too. It's a clear liquid, looking like water.
Of course you can find this Zhermack stuff/ silicon-oil elsewhere, just google for it.

You further need 4 shots (1 for silicon-oil, 1 for silicon, 1 for hardener and 1 for the final mixture, that you go to apply)
Then I would use small transparent tube to prolonger the top of the shots. You can get this, where you obtain the shots (Pharmacy-shop)

First do some mixture for testing, not for applying on speaker.
Let it dry and decide if its softness is OK (softness is defined by amount of silicone-oil). You also will get a better feeling about handling with this stuff.
Use some foam you have by hand (open-cellular structure) pour silicon on it and watch its behavior.

with my Duetta signature it was sufficient with only the front side siliconized (I used very little amount of silicone, maybe 6ml per foam line). My duetta1 needed both sides and more silicone 10-15 ml.

1. at one point, the silicone arrived at the bottom. Take a torch, see it shimmering
2. horizontally
3. 11 month with my Duetta 1. Yes (sine waves sweeping up from 20 Hz and pink noise)

olafzen

two things I forgot to mention
1)
if applying to the back, the position and angle of the apogee defines the path that the silicone takes down to the bottom along the foam. It's so liquid, that it flows into the foam. Pouring should be done very slowly.

2)
Silicone is completely harmless to your health or the environment. Once dried, it keeps its elasticity over a very long time.
It's resistant against UV rays.

[This message has been edited by olafzen (edited January 11, 2009).]

I don't see anything in this process that would "mutilate" the speakers or damage them in a long-term fashion.

The cost of ribbon replacement is very high. If a process like this offers (at the very least) a short-term solution I applaud it. A major repair down the line from one of your installers is certainly still an option. The majority of Apogee's are just like mine. Still in excellent shape with the exception of the foam. There MUST be a better way to implement a fix for these speakers in this day and age without tearing them completely a apart. Maybe this is it?

Whether or not "foam revival" is proven or dis-proven is beside the point. Olafzen has made the claim that (in his case) he's fixed the problem. Long term fix? We don't know yet, but he says it's been working for 11 months. That seems like money well spent to me.

Cheers,

Dave.

quote:

---

Originally posted by Al:
Olaf, the key word is Syringe or hyperdermic needle. oil cans work to.

---

Hyperdermic? What kind of skin is that?

Hello Art - The idea you have assumes that the back of the ribbon is as accessible as the front and that foam degradation is the only factor in ribbon aging. Any damping needs to be absolutely symmetrical in force, upper and lower force identical along the corrugation.

In truth - with ORIGINAL early Apogees this is the main area of decay in the bass driver, but with the foam I have made for me to order specifically for this application the usual problems associated with foam decay do not apply.

The real solution. Back at the start of designing a service to repair peoples speakers the foam was identified as a major weakness and I studied foams quite deeply to come up with an ideal one for the job. Tests included long term compressions at various rates, exposure and operation in moist and total water immersion. The foam I use has only been in field use for 6 years, but the accelerated wear tests I have have not decayed at all, still retaining their required properties 100%. It would consider it fair to suggest foam failure would not be a failure mode of speakers refurbished using my ribbons.

Art - you raise (again) business secrecy. I would not deny I am keen to protect my investment both for the sake of keeping my investment of time, learning, and money working for the benefit of my clients. The simple fact is I have the statistics - and those willing to rip their speakers apart gambling for possible gains are in the sub-single percent minority. Pandering to this drove me to the brink financially and with stress couple of years ago, and since new arrangements have been made Apogee owners have never been better serviced, in quality or quantity by a large factor. Though some in here might disagree strongly (and do in deed) - my work is generally considered actually useful to the Apogee brand. It should be noted that the tuning procedures are there for all to see, and I have been assisting Apogee owners for 9 years with their problems. Your own speakers you bought without availing yourself of the freely available buying tips buzz - and you are close to a repairer and as you clearly indicated to me in a phone call last year able to cover the costs of repair - so why are you still messing about? Seek out some restored speakers and see what you are avoiding

The thing with mutilated speakers is they change hands once the owner has abandoned his project, and they then become the problem of other people, and ultimately the problem of installers, or dumped. I have been dragged into several disputes between buyers and sellers over such situations before, a huge waste for everybody. For those reasons - I am not a fan of experimental procedures that affect or detract from a proper considered and proven repair by somebody who really knows what they are doing.

Hello Olaf! Wonder fluid. Foam is foam - bubbles. When the old Apogee foam bubbles pop and crumble to dust, no fluid will rebuild this. None. A properly balanced, 100% cured and non-oily, thickness controlled soft silicon polymer could actually be a good alternative to foam if applied during a new installation. Pouring a mid/high viscosity liquid into a place where energy dispersal is required will potentially change the situation from what it was before, for how long or by what degree who knows? Different applications of the same fluid would have variable results.

OK - Silicone oil truths. Using this material unknowledgably anywhere near a workshop is really a problem. I have several grades of it here, and am no stranger to using adhesives of many types. I have researched use of this in several areas. I actually have a problem with raw silicone oil as it is an EXTREME contaminant to anything it comes into contact with. Very small amounts of it can totally wreak havoc on a workshop that includes painting as a service, or sticks things together using any type of adhesive. Apogee clamps exposed to silicone oil would be effectively unusable as the cost to decontaminate them properly would exceed their cost to manufacture them. Worse still - nobody messing about with silicone oil is going to inform the next owner, or installer of it's use. Unwittingly, any installer with spray facilities or a spray booth could most likely simultaneously be facing 5-figure silicone cleansing costs, whilst likely doing warranty work (in ignorance of the oil) to repairs where installation adhesives had failed due to contamination. A little silicone oil goes a long way...

Tight times. Yes - perhaps not the time to gamble a potentially good speaker away whilst saving less per hour than what an average tradesman charges, for a "fix" with no warranty?

Tight times truth. Agreed, these are tight times for all. A person bringing a silicone oil contaminated speakers into an installers workshop could end up giving him a dire financial problem. I wouldn't take one in for repair knowingly...

Davey - repair costs and wonder cures. Everybody wants one, truth is the buzz that shows itself is more often than not in the ribbon from when they were originally hand cut. Good foam minimises this, but a bad ribbon will kill foam faster than a good one will. A properly fitted accurate ribbon over a good magnet array will buzz less and so require less damping - that's why some original Apogee's are still playing OK years on.

Lastly - Apologies for dual posting of this response, but as we have two wonder-cures this week, it would be fair to suggest that once they have drifted off the main page they will be considered separately by future readers as they discover the archive.

You really are excellent at playing devils advocate.

If you do this you're going to "mutilate your speaker?" C'mon!

I think everyone sees this procedure for what it is. There's no denying that a full servicing by one of your installers is the preferred solution, but there's nothing wrong with exploring these types of fixes. It appears to have decent potential to extend the service life of the speaker with minimal cost, and has zero negative impact on a possible full, future repair.

We're all big boys here and understand the possible risks and recognize the ultimate success will probably not be 100%.

I think everyone understands and appreciates what you've brought to the table for Apogee users. However, some users can't (or don't want to) afford those types of services. Your objective should be to keep as many Apogee speakers in service (by whatever means) as possible. Every pair that doesn't see the scrap heap will be a customer eventually. Paying you later is better than not paying you at all.

Cheers,

Graz-

1. I'm not sure if "the idea I have" you refer to is in this thread or the butyl thread. Yes, I realize an ideal solution requires equal treatment of both sides of the ribbon. However, for God's sake, we're talking about pouring an oil down degraded fowm. We are far from ideal here! We are talking about a temporary, perhaps long term, treatment.

2. Again, I respect your contribution to the forum and your business position. I did not "raise business secrecy" but acknowledged it in a positive manner. I said it was "fine".

3. I did avila myself of this forum's info when purchasing my Cal Sigs. I will post a detailed thread on that issue at a later time.

4. I did state in our conversation that I could pay to have mine rebuilt locally. I have acquired more equipment since then and this system is now secondary. So, a quick "fix" like this sounds appealing.As Davey pointed out, not all of us need the fulll service treatment you offer. Who knows, by the time I'm ready to proceed, you may be running a discount on the job or (heaven forbid) you'll allow DIY sales again.

5. I fully agree if your installer does not want to take on a project after a failed attempt with this treatment. As Davey said, and as I noted in our conversation, we are all big boys here. If I screw up a job so be it - I'm not about to stick it to you and cry about it! Let's not be paranoid again...you can easily protect your interest with the appropriate legal language in your rebuild contract.

How is silicone and it's oil suppose to revive old foam? When it dries, is it springy? It will adhere to the clamp and the panel. That will actually glue the panel to the foam it seems to me.

Carlton stopped the buzzing in his Scintillas by using some foam from Home Depot. I was going to do that, perhaps.

The open cell foam on my top clamp is as fresh as installed. There is no foam dust. I believe my problem is more likely a construction mistake.

The point is, my Apogee ribbon Scintillas are sounding fabulous, save for some guitar lower midrange sympathetic hum around the top clamp. I would love to rid that right speaker of it's one fault. I just have to understand the procedure you are using.

1. I think the oil simply fills the cells of the foam - sticking to the ribbon, foam and brace - and hardens to the familiar solid silicone. It can't revive foam. Which brings up the question: how can the ribbon dampen itself against such a relatively solid material? However, if it works - if just for a while - then it works.

Please respect science. Don’t make any claims without scientific evidences to support even if your business interest is involved.

http://www.google.com/search?hl=en&rls=com.microsoft%3A*%3AIE-SearchBox&rlz=1I7ADBS_en&q=silicone+oil+material+safety+data&btnG=Search

As for science - I have been using the oils (7 grades of it plus an understanding of viscosity mixing) for various things in a controlled area of the workshop for several years. My first (FK1) speakers used it in a targeted application. I have a great deal of respect for silicone, and first used encountered it in Max Townshend's workshop 25+ years ago. The simple thing is, once on fingers/gloves/parts being almost invisible it transfers around like a bad case of the flu for manufacturers!! Any surface it touches is rendered unpaintable, and most surfaces that are to be bonded have their adhesion ratings with almost all adhesives severely fractionalised, at best.

Once loose in the workshop - it is tedious/near impossible to clean and completely remove. If on clamps made from mdf etc it is NOT able to be cleaned without destroying the mdf. A real Apogee perimeter clamp assembly of requires good adhesion to silicone on assembly, and the ribbon is then tensioned. Extending the open time of the adhesive by 2 minutes results in 20% of the bond to be lost, this will cause a ribbon installation failure in practice. Silicone oil contamination will remove 90-100% of the silicone bond to the clamps, invisibly. Attempt to clean, and the clamps will swell, or break down. Verification of cleanliness is very difficult. The idea for silicone impregnation will (if achieved accurately) place silicone oil where adhesion is required for an installation, and where silicone adhesive is required for a strong bond. People with oily clamps will need new clamps. A simple truth.

Common sense triumphs over your particular version/application of science - and people oiled clamps are contaminated beyond reliable use if they have used the oil.

Now Jian - your point was made, as has mine. Let's not belabor or have a row in here for the experience, I am sure your time (as mine certainly is) could be better spent.

Graz out.

Anyway, this does not effect most people. In general Apogee owners have a fair amount of money and i would rather have a "real" solution. Depends on the person i guess.

Just for info: When i had my Grand's bass panel replaced by Rolf in Germany (he did a fantastic job) with the help of Graz they noticed that the ribbon had huge tollerances and they did not even line up over the magnets. That speaker was buzzing from day 1! Now think about this, this was a 85000$ speaker back in the early 90's when the dollar was actually worth something! And they had huge tollerances in it, no silicon wonder glue or oil is going to fix this.

Cheers

To graz:
I see fear is an evil beast. (in your case: fear of loosing business)

See ya folks

Oh ,I had to reedit my post, just to make one thing clear:
I don't bath my apogee in silicone-oil. I make a mixture, in this I put little amount of silicone-oil. Now comes important point: Once dried, the silicon-oil is completely bound into the molecular structure of the silicone, no oily mass. If I apply this silicone on wood, and remove it; not the tiniest amount of oil stays back. Oil is completely absorbed in the silicone. And the silicone mixture doesn't feel greasy, when dried. So all arguments from graz against silicon-oil are completely nonsense (in this case).
As said before: go and try and be glad :-)

And; IT SHOULD BE FUN.....

That's all.

[This message has been edited by olafzen (edited January 12, 2009).]

I am not looking to fall out, believe me. Nor in fear for the clients that find their way to me. Just keen to preserve the classic speakers in a lasting way.

I am certain the foam I have been using this last few years will last a very long time, far outlasting the original. Foam is just a small, but obvious part of the original picture...

concerning your post (January 11, 2009 10:39 PM): the rotten foam has still its open cellular structure (at least with my duetta1 and my signature). It only lost its elasticity. The silicone you apply sets itself on the inner frame of the foam. You have to take only very few silicone, you don't fill the "bubbles" inside the foam completely with silicone, only the structure.
After that the foam is elastic again (hence the silicone)
You should prepare you mixture, in that way that it becomes very soft, when dried (as stated out before: the oil defines the softness)

It's not big science

And, there exists different kinds of foam: closed cellular structure and open cellular structure. Fortunately the stuff that Apogee used is open-cellular.
Read all my posts thoroughly. Do some mixture, take foam (open-cellular) and test and you'll see.
Been there, done that.

quote:

---

Originally posted by olafzen:
Feel free to ask.

---

you are lucky. The stage has its backplate (were the magnets are glued on) removable.
So applying there (if neccesary) should be easy.

Consider that the cost of your experiment should include the entire cost you paid for the speakers, as they are pretty much worthless after this procedure.

The clatter might be due to foam I placed in contact with the cover. I still have to do a cover off test for each problem.

The top clamp touches the side clamp. That could be the whole problem. The cover peg has drilled a bigger hole. That too can be it. I have poured silicone into the hole. but that did not stop the hum. Given that failure, I will dutifully pull the serial plate off my worthless Scintillas.