New plastic domes for POLYDOME K

Augy

Well-Known Member
Looking at the bay the other day and I noticed a seller selling new plastic domes for the polydome k. Clear very flexible plastic domes to repair polydomes with. There is also that guy gluing new black paper domes on your old polydome for $85 too much IMO but the new plastic domes seem to be the best fix out there. I'm glad to see someone manufactured these new plastic domes..
 
I just sent him several questions since his description seemed a bit lacking.

Like; what are they made of, are they original infinity, do you make them yourself, etc.

I would think he would do alright if he had come up with a way to make them and they worked without too much install trouble.
 
Agreed

Just stumbled across them and since there are many threads on the issue decided to post for all akers to see. Seems like the best option I have seen to revive and old decayed dome.
 
I saw those too, but I wondered what they were made of, and maybe more importantly, was tying to figure out what the installation would be like. I've taken apart several Polydome mids, and the dome diaphragm has to be glued to the voice coil. It's not at all clear to me from his picture of the domes that this would be a simple procedure: In fact, I think it would be quite a challenge to do correctly, although maybe I am over-thinking it.

And if he is manufacturing them himself, if would be nice if he would sell them BIN, and with much more information about them, than in an auction which makes it seem like what he has are NOS Infinity domes (which I am certain is not the case, since they would come with he voice coil attached).
 
Here is his reply:

"Hi,no they are not original they are made by me and the material that they are made of is a very strong silicon.Thank you!"
 
If I'm not mistaken i think silicon is much heavier than the original poly diaphragm's, also... i spoke with my brother who has been selling for a friend that makes silicon super tires for slot cars for over 20 years and he said that no glue will stick/bond to silicon, so you will not be able to attach the voice coil to that diaphragm if it is made out of silicon.
 
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I have a feeling the winner of that auction will not be happy upon finding out that you cannot just pop in that "new" dome and make the driver work again. Gluing a voice coil to a dome in such a way that the driver will work properly wouldn't be easy even assuming that the new dome would be easily bonded by glue.
 
If I'm not mistaken i think silicon is much heavier than the original poly diaphragm's, also... i spoke with my brother who has been selling for a friend that makes silicon super tires for slot cars for over 20 years and he said that no glue will stick/bond to silicon, so you will not be able to attach the voice coil to that diaphragm if it is made out of silicon.

Not trying to be a smart ass but maybe just use silicon caulk. That stuff sticks to everything.
 
Not trying to be a smart ass but maybe just use silicon caulk. That stuff sticks to everything.
Silicon is not a glue it's caulk and does not have the bonding strength like glue has, unfortunately silicon caulk does not stick to it's self once it is fully cured, we have been trying to find a glue that will bond to silicon for over 20 years, nothing sticks to it.
 
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So I asked;

"Yes but what type of glue. I don't know of any glue that will stick to silicone."


To which he replies;

"aquarium glue"
 
Not only do you have to glue the voice coil on (or attempt to), you apparently have to remove the original dome from it's frame and attempt to glue the new dome to the frame. This means, of, course, if you make a slight mis-alignment in attaching the whole new assembly together, you have probably just destroyed a driver. There likely won't be any reattaching the original dome after that.

Additionally, if there is a successful glue, there will be a wide variation in workmanship. Invariably, some attempts won't be successful. Like post #9 Skylab said. And, how will various levels of workmanship affect the performance of the driver?

I wonder if these have been engineered and tested to align the T/S values and sound characteristics with the original. This is the first time I've heard of someone making a dome or diaphragm out of silicone. I looked at the picture of the dome being (what appeared to be freely) twisted, and it seems odd that a material with such a lack of rigidity would be successful at the crossover frequencies in question, like 5000Hz for some of the Kappa's. This has to do with the center of the dome decoupling from the driven edge portion and essentially acting out of phase with the driven portion at high frequencies. I'd be really curious about that. Equally as curious about the low crossover frequencies, too, regarding the rigidity of the dome.

Just a couple thoughts.
 
I Agree with the last post, looks like the guy who made them did a good job making the mold but should have used a different material for the dome so that it would be a little more rigid plus and most important so that glue would Bond to it, as i said before silicon caulk is a caulk/sealer not a glue it has poor bonding strength, Genesis speakers use to make what looks like to be the same exact mid range driver as the polydome with the only difference being it had a titanium dome.
 

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The only way this wouldn't end up in angry buyers would be if the guy offered a whole service, to install his new domes on the existing drivers of a buyer. Make you wonder if he has even successfully tried to do it once himself!
 
The only way this wouldn't end up in angry buyers would be if the guy offered a whole service, to install his new domes on the existing drivers of a buyer. Make you wonder if he has even successfully tried to do it once himself!

I believe that is what I'd ask. If he can install them in your driver for a fee. The est is speculation and valid. I'd have to hear them. Perhaps they are better than nothing regardless. I'd buy a pair of used drivers in good shape myself.
 
Given how high the price is going, I can almost guarantee that there is a train wreck a-comin'.
 
Given how high the price is going, I can almost guarantee that there is a train wreck a-comin'.

Ended up selling for nearly what a decent set of used complete Polydomes cost. Almost as much fun to watch as the used Polydomes with the domes missing that are claimed to still sound good by the sellers.
 
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