[Don Ferguson]

I've searched and do not find any information on the damping element on the acoustic clarifiers. It seems that many of the calrifiers are subject to having the damping element melting and running down the metal frame and not being a part of the cone damping anymore. The damping element started life as a piece of rubber and turned into drippy rubber glue. My questions are: Is anyone familure with the sound of a cabinet with good clarifiers versus one with the damping element melted out? (relate a comparison) Next question: Has anyone attempted to replace the damping element on a clarifier? Next question: I have just finished replacing a damping element in a clarifier with a piece of rubber band and have taken pictures and documented the process: Would it be worthwhile to go to the trouble of writting it all up or has someone gone before me?
Thanks to all.

[Skip]

Dom

I have replaced the rubber on the clarifiers. I followed this method from YouTube. You just use the silicone bands everyone seems to be selling and wearing now.

http://m.youtube.com/watch?v=Y42KmweyhMM

I have not put them back in my cabinet yet. Not quit done. Was not too hard to do.

[Don Ferguson]

Skip, thanks a bunch. I'll check it out.
Don

[Ronin61]

Don I've got five clarifiers at my house and all of them need this fix, if you hadn't mentioned this I would never have known this repair was required to get these to do the job they were designed to do. Thanks for bringing it to our attention .[Image: http://i1281.photobucket.com/albums/a508...d3ad01.jpg] my Philco 116x that looks like it has the rubber but I'm going to replace them anyway.

[Don Ferguson]

Ronin61, it looks like you and will be working on yours and mine together. My recent purchase of a 37-116 has the melted dampers on the clarifiers as well.
See you Monday

[Mondial]

I am not sure if the original material for the dampers was rubber or some other substance. The Philco patent for the clarifiers specifies "viscoloid" as the damping material, but I have not been able to find out if viscoloid was an early plastic or some rubber compound.

In any case, a replacement material has to be a lossy substance in that it should convert motion into heat. If it just stretches and rebounds as usual rubber does, then there will be no damping effect and it might as well not be there at all. If you are lucky enough to have clarifiers with intact damping material which has not disintegrated, it might be well to leave them as a sample of the characteristics of the damping as originally designed

Here is a link to the patent which goes into a lot of detail regarding the design of the clarifiers and how they work. Perhaps it will be of some help in choosing an effective modern replacement damping material.

http://www.google.com/patents?id=4KdBAAA...dq=2059929

[rfeenstra]

Interesting! I suspect that the dried out paper of the cones and the deteriorated dampers significantly change the resonant frequency of the clarifier. I may have to play with one to determine the resonant frequency of the clarifiers on my 37 and 38-116's. If they can be brought back into the designed frequency, they may be more effective in reducing cabinet boominess. Thank you for the link to the original patent!

[rfeenstra]

Wow! I just realized how old this thread is!

[fenbach]

whatever is the "resonant frequency of the clarifier?" and how would you find it??

[rfeenstra]

The resonant frequency is the frequency that the cone will want to vibrate at most easily. All speakers have a resonant frequency . it would have to be determined experimentally. The patent gives the desired/designed frequency. It would be interesting to compare actual "aged" frequency with original designed frequency. If the current resonant frequency is far away from the original, it may explain why some have said they are not very effective at reducing the boominess of the cabinet.

[fenbach]

And what would be the experiment to determine the resonant frequency of a speaker?? Are the patents with the designed frequency available somewhere?

[Eliot Ness]

A link to the patent is listed in post #6 above. Just glancing through it looked like they were dampening frequencies 70 - 150 for one size of the clarifier.

[rfeenstra]

Normally tapping the cone will make it resonate. You could then measure the frequency from the voice coil. Since these have no voice coil, one can't do that. Perhaps, put it next to a speaker driven by an audio generator and sweep the frequency until the clarifier cone moves the most. that would be its resonate frequency. There are probably better ways, though.

[Brad Winder]

I recently purchased a Canadian 3116X, and the "Viscoloid" is all but gone. But the Clarifiers in my U.S. 116X are all intact. Id like to get both sets working, and compare the two...

If replacing the rubber with silicone bands will work, I'm all for it. But if it won't make them resonate at the appropriate frequency, I'd too like to replace the rubber with a more appropriate material.

[Brad Winder]

https://en.wikipedia.org/wiki/Dupont_Viscoloid_Company

Very interesting...