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Polydome K

A

aboroth00

Member
I stumbled upon a Infinity Kappa 6.1 Series II which had its polydomes in good condition. I was looking for a midrange replacement for my Kappa 7's and thought those polydomes would be a good deal.

However, I wasn't too sure they were actually the same original polydomes used in the Kappa 7's. Can someone clarify the difference or similarities between the Kappa 7's and the Kappa 6.1's. Are they the same driver? Will the function the same? Will they fit in the Kappa 7's?

Thanks for the help
 
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Okay, so i figured out they have different parts numbers 902-5793 for the Kappa 6.1 and 902-3075 for the RS kappas. I do realize there is a difference, there's a grill behind the domes in the newer domes. Any verification that these are the same drivers? I've searched some threads but no confirmed answers.
 
They will work fine

aboroth00 said:
Okay, so i figured out they have different parts numbers 902-5793 for the Kappa 6.1 and 902-3075 for the RS kappas. I do realize there is a difference, there's a grill behind the domes in the newer domes. Any verification that these are the same drivers? I've searched some threads but no confirmed answers.
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They are somewhat different though, The 6.1 will have a wire mesh under the dome where the original kappa did not, Some say the dome material is different as well but I am not sure of that. they are essentially the same driver other than those differences and will work fine...
 
Sounds good, the domes look very new as a matter of fact which was why i was very happy about the purchase. Very little yellowing and it mostly clear. Now the question is how do I keep it that way. There seems to be so many tricks and solutions I'm not so sure what to do.

As a chemist, I should be looking for something that lubricates that would hold in moisture while it doesn't promote deterioration hmmmm.....
 
The grill behind the domes makes NO discernible sonic difference; it does, however, help keep the domes from being poked in by curious little fingers... Even within the same exact models/series, you'll find some have those grills and some haven't. It was just something Infinity started doing at a certain point, one of those mid-production changes.
 
I am not saying you should do this...

aboroth00 said:
Sounds good, the domes look very new as a matter of fact which was why i was very happy about the purchase. Very little yellowing and it mostly clear. Now the question is how do I keep it that way. There seems to be so many tricks and solutions I'm not so sure what to do.

As a chemist, I should be looking for something that lubricates that would hold in moisture while it doesn't promote deterioration hmmmm.....
Click to expand...

But I have seen and heard of the domes becoming clear again using headlamp anti yellowing lotions made for auto's on the domes. I myself have the willpower to leave well enough alone.Which is very unusual for me!! The color has no effect on sound and is purely cosmetic as long as the material itself is still soft and pliable. I keep my grills on so you don't see them anyway!!
 
Thanks for all the tips. Info was pretty much as I thought. As for the domes, domes on the much newer 6.1 Series II will go nicely into my Kappa 7's but it's too bad I have to piece out a nice speaker to put life into an older speaker.

Hopefully I'll be able to find some K9's to justify my amp purchases in the near future.

Thanks all!
 
Augy said:
But I have seen and heard of the domes becoming clear again using headlamp anti yellowing lotions made for auto's on the domes. I myself have the willpower to leave well enough alone.Which is very unusual for me!! The color has no effect on sound and is purely cosmetic as long as the material itself is still soft and pliable. I keep my grills on so you don't see them anyway!!
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I would disagree. There is more benefit than just cosmetic. Cleaning them with rubber type conditioners will also make them more supple. It is either that, or watch them turn hard and decay over time ;)
But I would also say it should not be done to a polydome that is in to bad a shape to rub it with a soft cloth. Those I would leave alone as they are past the point of help really and would do more damage than good.

I did mine with excellent results. They are much softer and cleaner and should last another 60 years hopefully.
 
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uvafan420 said:
I would disagree. There is more benefit than just cosmetic. Cleaning them with rubber type conditioners will also make them more supple. It is either that, or watch them turn hard and decay over time ;)
But I would also say it should not be done to a polydome that is in to bad a shape to rub it with a soft cloth. Those I would leave alone as they are past the point of help really and would do more damage than good.

I did mine with excellent results. They are much softer and cleaner and should last another 60 years hopefully.
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Uvafan

I have always been told that once they start to sriffen it's all downhill from there. What kind or type of rubber conditioner? Any brand names or recomendations? If this is true this will be a BIGGGGGGGG relief.
Thanks, Martin.
 
MJWPicMan said:
Uvafan

I have always been told that once they start to sriffen it's all downhill from there. What kind or type of rubber conditioner? Any brand names or recomendations? If this is true this will be a BIGGGGGGGG relief.
Thanks, Martin.
Click to expand...

Sent you a response to your pm.
 
kappa7krazy said:
Uvafan, I am interested in this info as well. Would you mind sharing? Thanks, Brian
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I am sure people have used different types of stuff with various success. But I used Meguiars vinyl & rubber cleaner/conditioner. Which is found online or from a auto store as well...
 
uvafan420 said:
I am sure people have used different types of stuff with various success. But I used Meguiars vinyl & rubber cleaner/conditioner. Which is found online or from a auto store as well...
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Might give this a shot...Is it the product which is for boats or autos?
 
speakerex said:
The original Polydome K mid and the diaphragms to repair them have not been available for quite a long time. We found another brand 3" replacement mid that works as a great alternative. You can see the original mid and the replacement option side by side for comparison at http://www.reconingspeakers.com/pro...polydome-k-902-3075-qls-midrange-replacement/. Hope this helps!
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That driver will not work as it is 8 ohms, the original polydome driver is 4 ohms, you would have to do some mods to the crossover to get that driver to cross over properly and even with the mod it probably wouldn't play loud enough as the original was 4 ohm, some people buy that driver and remove the voice coil from it and attach the dome to the original polydomes voice coil and housing with good results..
 
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The originals were 4-6 ohms. The DCR on the replacement is 5.9. We use them ALL the time without crossover mods. They work great and as the original is NLA, we find it to be the best option. To each his own though
 
speakerex said:
The originals were 4-6 ohms. The DCR on the replacement is 5.9. We use them ALL the time without crossover mods. They work great and as the original is NLA, we find it to be the best option. To each his own though
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Actually the impedance is more like 3.7 ohms on average on the polydomes, i have tried the replacements and they don't sound as good as the polydomes to my ears but like you said to each his own.
 
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