Apogee Buzz Fix

Another Apogee Buzz Fix?

Hey all,
I happened to keep old posts sharing successful experiences of fixing buzz. The idea is using the Frost King, "Vinyl Foam Weatherseal Self Stick Tape" to provide damping instead of using silicon. Since I plan to fix buzz of my Diva, I am seriously considering to select an approach out of the two: to stick weatherseal tape or to inject silicon. I would like to listen to the opinions of John65b and Taotao. Listed below are the posts.

Full Member posted January 15, 2001 08:33 PM
Has anyone discovered the true source of Duetta woofer ribbon buzzing? I took my speaker apart and played low frequency test tones through the speaker with the tweeter ribbon removed and the eight tuning screws exposed. Adjusting the ribbon tension resulted in a slight shift in the buzzing but I cannot remove the buzzing completely. The buzzing clearly appears to be originating from the ribbon membrane itself. It almost sounds like the aluminum conductor pulled away from its capton backing and is vibrating against it, though I cannot see any indication of separation.
All the clamping bar screws are tight. The woofer otherwise operates normally. This is very perplexing.

Full Member posted January 15, 2001 11:50 PM
My Duetta's have the same problem. I never tried tensioning them, as I'm afraid this might do a lot of damage in the somewhat longer run. (metal fatigue/cracks!)
I don't know how you call the stuff in english, but I attached a self-adhesive foam strip, the kind that is used to fill gaps inbetween door and doorframe to prevent drafts, all around the circumference of the woofer membrane. The adhesive is on the MDF frame, NOT on the membrane. The foam is pressing against the membrane gently. THis trick removed 95% of the membrane buzzing in my case.

My guess is that the original foam strip that is inbetween the MDF clamps and the membrane are in just the same horrible shape as the foam strip on top of the MDF clamp. (In my speakers they were completely rotten)This causes the membrane to sometimes hit the MDF clamps, causing a rattling sound.

Good luck.

Full Member posted January 16, 2001 04:46 AM
I have a new boxed pair of D-Sigs - and the problem is NOT there. The theory about the foam is sound - as the foam breaks down over time leaving a comparatively fresh acrylic adhesive more exposed... Henk has a good solution here with the foam additional "inline" frame - and this makes good sense to me before you all go retensioning your basses! There are soft closed-cell foams I am experimenting with now that perform better than the originals - which in all fairness were using 1980's technology. I stumbled on this while making an evolution spring for the 26-6 units, and any I supply from now on will have these as standard.

Full Member posted January 17, 2001 10:03 AM
My thanks go to Henk for correctly identifying the source of my Duetta woofer buzz and suggesting a solution. The problem stems from deterioration of the foam dampers surrounding the woofer diaphragm. As they disintegrate the aluminum conductor begins to make contact with the hard wood clamp causing a buzzing sound. The buzz emanates from the conductor itself and not the clamp. Since the conductor is corrugated it is the raised portion of the aluminum that buzzes as it vibrates against the clamp - just like a tin can would buzz if set in a sink with the disposal running. I know many of you Duetta owners are experiencing the same problem, and if your not now you will be in the not too distant future as the environment and use take its toll on the foam. My feeling is if the buzzing is not eliminated the aluminum will eventually wear out at the point of contact and cause the driver to fail. Fortunately Henk suggested a solution which I implemented and refined and will now share with the rest of the group. The standard apogee work cautions apply to remove all metal objects from your pockets and work area in addition to keeping your fingernails short.
I experimented with a couple of foam types and found the Frost King, "Vinyl Foam Weatherseal Self Stick Tape" to work very well. Obtain the �" X 3/16" X 17' roll package which says 3 year warranty (I am certain it will last a lot longer) and moderate compression. It is grey in color.

Lay the speaker down on a large box or low table and remove the speaker's supports and cover. Reattach the support legs and stand the speaker up. You should work with the speaker standing up and not laying down so that you do not accidentally damage the woofer with the tape roll as you work. Carefully remove the top and bottom dampers by unscrewing them and very slowly lifting them off (the yellow Kapton showing between the conductors is sticky). Note that the rear beige material may be stapled to the top clamp as it was with one of my speakers. Before removing the clamp pry the staples out with a small screwdriver to release the material. Scrape the rotten foam off the dampers with a putty knife and replace it with a piece of new foam.

Unravel enough foam to reach from the top of the speaker to the floor with the roll lying on the floor (be careful as the tape adhesive is now exposed and it is very sticky). Beginning on one side of the woofer frame attach the free end of the tape to the top of the clamp side perpendicular to the ribbon (not on the ribbon!). The area is the same width as the tape, �". Start 1mm from the edge of the clamp closest to you and gently press the tape on with a rolling motion from the outside edge toward the ribbon edge. You will notice the tape pushing on the ribbon as you attach it. You need this slight force to make sure contact is made with the conductor after the tape compresses. In my trials I found if the contact weren't adequate it would be ineffective an hour after the foam compresses. Keeping that 1mm gap work your way down the length of the ribbon and cut the tape at the other clamp end. Repeat for the other side of the driver. Replace the two dampers tightening the screws only enough to keep the damper in place and pushing on the ribbon. Lay the speaker back down, remove the supports, reattach the cover, put the supports back on and enjoy buzz free sound.

IP: Logged

Full Member posted January 17, 2001 03:55 PM
As mentioned I have access to a number of foam products, and closed cell will last longest. tape widths make a difference too, and I have stumbled on a great supplier down here of all our needs. Draught insulation can be a bit wide for the job, and also often has a plasticised outer edge to be "non stick" on doors. Using this foam will damage your conductors...

Again I am eager to have your feedback, and especially those form John65b and Taotao, so that we, apogee lovers, may have a better solution to this inevitable problem.

Joined 2005
Paid Member
Adjusting the ribbon tension resulted in a slight shift in the buzzing but I cannot remove the buzzing completely. The buzzing clearly appears to be originating from the ribbon membrane itself. It almost sounds like the aluminum conductor pulled away from its capton backing and is vibrating against it, though I cannot see any indication of separation.

I agree with this completely. Injecting Silicone or better foam dampning the edges works to a point, but you turn the volume up louder and the buzzing is still there. The tuning instruction manual states that onset buzzing at 11VAC at speaker terminal is acceptable. This 11VAC is quite loud, but leads me to believe completely removing buzz is not possible, and Apogee knew it was a design fault.

I have watched the bass panel of my scintillas very closely and noticed slight localized "bows" or "bubbles" in the horizontal conductor runs that have higher amplitude when driven hard, causing buzzing. When extreme, these bows or bubbles appear as wrinkles or waves, and once they are that bad, buzzing is quite noticeable at low volumes. I also think there are two forms of buzzing - one is the slapping against the clamp where foam is gone, the other is a rattling of loose aluminum/kapton area, kinda like shaking a sheet of aluminum foil. I know the corrugations are supposed to reduce aluminum rattling noise, but maybe only possible when consistently and properly tensioned.

Running my hand slowly down the panel I can feel variations in tension on my one buzzing panel, while the other not badly buzzing panel (quite acceptable actually) seems pretty consistent.

I think the adhesive in some places between the wooden clamp blocks are getting loose, causing localized low tension, allowing wrinkles to form and buzz. Re-tensioning just puts more tension on the diaphragm area that is properly holding, and making the loose connection worse. I can see the loose part of membrane vibrate and buzz, while just above it it is perfectly flat, stable, and probably not buzzing.

My Duetta Signatures panels are a lot better shape than my one Scintilla panel.
Only at very high volume can I hear a slight buzz.
Thanks for all this info on Apogees fixs...
john its always one panel then the next....i just cant live with it............lov the speakers..........but....
last Stages i got for $400. for the pr...get a pr if you run across.....lot of fun...real keepers...
i know the Stages only has bass drivers the size of 4ea12"cone type drivers an 20ea 1" tweeters but some how i can live with it.....
an NO buzz
..good luck
North Creek ........ George Short.....
In 2008, during development of the Fibonacci Technologies' Vaya! Loudspeaker I kept of a pair of upgraded Stage's and a pair of Duetta Signatures in my listening room as reference. I can say with no reservations, the Duetta Signatures are great speakers, but the upgraded Stage's blow them away.

His crossover in the pic...he worket with jason...on the Apogees
I got a littel info from him an put some mods on the Bass driver....AZobel res.cap....an made the trap on the MT a littel biger....his setup looks great
I keep all coils stock.... Jason like the sound of lose coils ...an so do i...tride others.....
Stages rock...had a guy i did some tube amp mods on his VTL 200s ... ran the VTLs ln to my Stages...offered me $2k.....on the spot....he has new SoundLabs..he had never heard the Stages before....mind binding.....lot fun

I say the Stages Holes up ....it can be moved...i can pic it up off the floor an cary it....try that with a Duetta Sig.....
I have a pr of the Centaur minors....there MT crossover higher....same MT as the Stages...vary sweet.......got them for $200 for the pr...keepers...


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