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Old 28th August 2013, 03:57 PM   #221
tyu is offline tyu  United States
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Join Date: Jul 2009
Post on the fourm...or just E-mail....GraZ.....well know......he has an dose re-worket all Apogee ribbons...an mag re-lines...i have Stages an other Apogees speakers...but no not what mag are used

Last edited by tyu; 28th August 2013 at 03:59 PM.
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Old 30th August 2013, 05:08 AM   #222
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Location: Jackson,michigan
I have been PMed this very same question "what grade of magnets are used?".

Sorry,I do not know what grade of magnets were used.

I don't know what types were available in the late 80's when they were built.

They appear to be of the same grade that used to be commonly sold at radio shack in similar sizes for $.99 ti $1.19 only thicker.
Overall they are the exact same size only thicker.

I have experimented with such magnets and they appear to be about the same strength for an equal thickness.

I had stated this info somewhere in one of the threads, But since threads very easily get buried I couldn't tell you which one it was, as it was a while ago.

I would assume they would be of grade 8.

Maybe some of the earlier models were a grade 5 or something as I have read that some of the later models may have had a higher efficiency.
But they could very well have used more of them instead for that matter.

My set was made in March of 1987.

I had made a magnetometer a while back where I could measure the filed strength but I don't have a known type that I could use to calibrate it with.

I can tell you that every time you double the thickness of a magnet of the same type you also double the lines of forces therefore doubling its strength.
Just like putting two 1.5V batteries in series you get 3V.

I can tell you that they are ceramic magnets and that is all I know about them for now until I can build a calibrated magnetometer.


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Old 30th August 2013, 05:18 AM   #223
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Thank you very much Jer. I will buy some ceramic magnets for replacing and I will share with you guys after finishing whole works.
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Old 1st April 2014, 07:21 AM   #224
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Hi all, I am Apogee fan. Anyone tell me which Vol position can Apogee Duetta Signature play best with no buzz and no cutting on high frequency on bass panel ? My Pre Amp is Aragon.
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Old 18th October 2014, 02:49 PM   #225
Samppo is offline Samppo  Finland
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Join Date: Nov 2002
Location: Finland
As it happens I recently acquired my first pair of Apogee speakers, the Stage. These suffer from a sort of "flapping" sound from the woofer panel, and a slight buzz, much more evident on one speaker than the other.
I started checking them out and found that on the rear, foam is almost gone or sort of sticky-goo consistence using a flash light to inspect them. Searching through the old Apogee forum I found that Graz recommended loosening the woofer panel clamp screws 1/4 of a turn. It helped quite a bit, but still some buzz could be heard. As I read on the old Apogee forum and on this forum, member taotao's clever silicone method could be easily used, especially as on the Stage the perforated steel can be removed from the rear side without destroying the woofer membrane. This way I could also easily inspect the rear foam much better. So I ordered some Zhermack HT33+silicone oil through amazon.de from Polymer-schmiede.

I started by dismantling the perforated steel with magnets. The magnet plate is attached with screws and some sort of silicone, so I had to make tools to safely remove it. First I tried with some zip ties starting from one corner, without success. I decided to use a bit more force, bent a nail and wrapped some tape around it. Then set the nail through the perforated steel and started pulling with the hammer from one corner using a piece of plywood as a sheet between. It helped, and after a few gentle pulls I could move on to the zip ties. On the second speaker the steel could be pulled with just the zip ties. Just need to be very carefully not to damage anything. Finally I very gently vacuumed the woofer suspension area from debris.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

When inspecting the rear side I could see on one speaker some silicone that appeared to have been there from factory. From the looks of it, it appears to have bursted from the clamps when installing the woofer panel. Probably too much silicone. It had bursted throught almost the whole clamp. Factory-made buzz removal? This was on the speaker with almost no issues.

Click the image to open in full size.

For injecting the silicone I used a syringe with a soft tube on the end. For now I've only "fixed" one vertical clamp on both speakers.

Click the image to open in full size.

Click the image to open in full size.

I used a mixture of 20ml base, 20ml catalyst and 14 ml silicone oil based on some experiments. About 2/3 of this amount was needed the fix one rear clamp on both speakers. It took some time as the silicone slowly creeped through the old foam, and more silicone had to be added.

Keep fingers crossed that this will work! I will let you know later on as I proceed.

Last edited by Samppo; 18th October 2014 at 03:13 PM. Reason: grammar oops
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Old 18th October 2014, 02:55 PM   #226
Davey is offline Davey  United States
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Terrific post. Good ingenuity and process.

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Old 18th October 2014, 03:19 PM   #227
john65b is offline john65b  United States
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Bah!!! I wish they had made ALL the Apogees this way! That is a HUGE benefit - I did not know the Stages back panel could be removed!

Enjoy your NEW APOGEES - without having to pay $3k for new ribbons.
I Speak Spanish to God, Italian to Women, French to Men, and German to My Horse. Charles V
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Old 18th October 2014, 04:19 PM   #228
artm is offline artm  United States
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Location: Boston, MA USA
Some thoughts:

1. We, meaning Apogee DIY members, have always been "officially" discouraged by the "true" Apogee members of the Apogee forum about attempting to repair the buzzing issue. I cannot recall one post where it was noted by those who knew, and there must have been at least a few who did, that ANY Apogee's back panel could be unscrewed to access the rear bass foam. Never mentioned! Now I see why: because there is a cheap repair available which goes against certain interests, at least for this Apogee model.

2. How are the magnets attached to the screen? I always thought that there was a real risk of them falling out. That's why you never transfport Apogees upside down, always the front is up. I think you were very fortunate that one didn't fall on the ribbon.

3. Rather than pour new silicone into the old foam, why not take out the old foam, pour some silicone in the slot and press in new foam. The silicone then acts as a glue to hold in the new foam. Since it is new foam, it will not deteriorate - without the need for silicone poured into it.

I look forward to your update.
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Old 18th October 2014, 04:30 PM   #229
tyu is offline tyu  United States
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Thanks for the info an pic......
My got frist pr of Stages.....93....have had 5pr....i have had no buzz in any Stages.... not even the pr i am playing now .......Duittas sig...had 2 pr BuzZ........ all Apogee Full ribbons i ever saw... other than the Stages Buzzzz at one note are more...........

Cant move them after there New out of the Box frist time..you were good to go but oneces there move 50'....it started...
I think its the 100lb are more in magnets....An the foam root rott ..

But the stages............at 60lb ea can be move an still live an not buzz...an can be driven with tubes..........lot of fun......$3-400. a pr off CL...
most feel thay well die any min....like a give away...nuts

One thing for sure....dont put to much daping on the back magnet plate ...damping it good.. sound like the thing to do.............but..
i have felt if i ever pulled my magnet plate off i would not add any new damping ..
I have found that if you add just one are two peaces of damping like blu tack on the magnet plate.... it makes a Big diff in the bass an the over all sound...1or 2 ok..3-4 not so much.... An as for the silicone Fix..an not foam...it
Well chang the sound!....i would add only at the buzz spot..if i could....less is more...
So if to much damping is added it wlll take some life out of the sound....it changes the topend an mid blind.........just saying... Good luck....great sound

Last edited by tyu; 18th October 2014 at 04:37 PM.
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Old 18th October 2014, 05:11 PM   #230
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Good Deal !!!!

You got lucky Samppo!!!!

The Duette's have their magnet plate mounted from the inside to the back panel.
I had considered this, But I would have to cut the back panel around the perimeter of the magnet plate while devising some sort of jig to keep the whole assembly from falling in and crushing the diaphragm!!

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