Infinity Kappa 6.1 Polydome repair

chevydan6

Member
So I'm looking into this Polydome situation and my polydomes have this metal matrix under them and the silicone material on top. 1 is good the other has a crack in the silicone. The Polydome with the crack breaks up at higher levels by sounds fine at lower levels. So the question is, is the voice coil attach to the silicone dome or the metal matrix underneath and the silicone just dampens? Is the breakup because of the cracked silicone or is the driver just completely shot?
 
The voice coil is attached to the dome. The metal underneath is just to offer some protection so the domes don't get fully pushed in when touched.
 
Hope you get it resolved . The dome is not silicone .. They are Polypropylene ( Whole different animal ) A eb seller offers silicone domes that I believe have been tested and rejected .. If the polydome were made of silicone it would be called a "Sillydome " :rflmao: Don't know if you are familiar with Millersound polydome repair .. It would prob mean youd have to have them both re done as Millers is a grey dome .. but very good reports from those who have had mids re done there ..:music:
 
I believe they would sound dead ( and Silly ) Ever hear of a speaker maker featuring Silcone drivers ? They are good for breast implants ( but not sure how those would sound ) Probably a bit "Squishy "
 
To get back on topic, as polydomes age, they get stiff. When they get stiff enough, they crack.

I don't understand the desire to have a replacement with the dome and surround the same material.
A stiffer dome can actually play clearer at louder levels than a stock dome. However, the surround being stiffer results in a frequency response shift and the polydome becomes more strident. Original polydomes tend to do this as they age and stiffen, even if not cracked.

To me, and your opinion may be different, the ideal polydome fix is to use different materials: a stiff dome for lower distortion, and an appropriately compliant surround to make the driver match the response of an original, yet with lower distortion. And there is someone that does just that, and the repair to your dome usually costs less than buying a replacement driver.

Send them to Bill LeGall and be done with it.
http://www.millersound.net/infinity-kappa-polydome-repair.html

I am not affiliated with Millersound, I'm just happy with my rebuilt polydomes after trying a pair of undamaged, used (but too strident) , originals.
 
Thank You Brian !!! :rflmao::rflmao::rflmao: I needed a great laugh ! Breast Implant Stereo .. ! o_O :music::music::music: Sounds good to me .
Also thanks for the informative post ! Glad to hear from someone who has had domes redone by Bill . Are you saying that the replacements ( I assume they are the ones w inf logo ) sound better than stock ? or at least better than an older pair that has discolored but not yet cracked ? Mine are original and while yellowed still sound wonderful . ( Things are always so recording dependant its hard for me to attribute any sound character to polydome degredation vs recording .) Wondering if Bill may have selected that particular "dome " for being a bit stiffer than Polypropylene ? I recall way back when Infinity started advertising the New lines that used Polypropylene drivres that there was attention payed to sonic properties of Polypropylene s a selling point .. Hard to believe it would be irrelevant what material is used .. So many misses and only one apparent hit ( Millersound repair replace ) :angel:
 
I don't think that Infinity considered the material to be irrelevant, it was probably the best solution that they found at the amount of money that they wanted to spend. However, it's worth noting that they also made the RSDS polydome for the automotive market, with IMG domes and a cloth surround, which has no such deterioration issues, and can be used as pretty much a drop-in replacement for a Kappa polydome, assuming you can find them, which is almost impossible.
 
Thank You Brian !!! :rflmao::rflmao::rflmao: I needed a great laugh ! Breast Implant Stereo .. ! o_O :music::music::music: Sounds good to me .
Also thanks for the informative post ! Glad to hear from someone who has had domes redone by Bill . Are you saying that the replacements ( I assume they are the ones w inf logo ) sound better than stock ? or at least better than an older pair that has discolored but not yet cracked ? Mine are original and while yellowed still sound wonderful . ( Things are always so recording dependant its hard for me to attribute any sound character to polydome degredation vs recording .) Wondering if Bill may have selected that particular "dome " for being a bit stiffer than Polypropylene ? I recall way back when Infinity started advertising the New lines that used Polypropylene drivres that there was attention payed to sonic properties of Polypropylene s a selling point .. Hard to believe it would be irrelevant what material is used .. So many misses and only one apparent hit ( Millersound repair replace ) :angel:

I bought yellowed but not cracked original Infinity polydomes to replace a damaged orange colored pair, and adjusted my level controls until the Kappa 9 sounded close to a Monitor Audio RX6. I had to jack the mid-bass coupler way up, and turn the tweeters way down. The polydome level was set in between the extremes. I sent the orange pair to Millersound for a rebuild, and after reducing and fluffing up the stuffing behind the polydome, and installing the rebuilds, I could set all controls near the midpoint for good balance.

I have never heard a stock original in its new, clear, state.

The one thing I didn't try, but would be a good experiment, is to put the yellowed pair back in and listen with the reduced stuffing.
 
"RSDS polydome for the automotive market, with IMG domes "... I have seen those RDS "Polydome " but never realized they are IMG Domes . Wonder if in a blind test anyone could tell difference between RDS and original .( And blind test between Millersound re do and original ) :idea:
 
I have the RSDS polydomes so I can tell you they are not IMG, they are a stiffer poly than the originals with an accordion edge that will last a lifetime.
Here is my take on their sound:
They do sound a little more forward than the original because they're slightly louder, if you turn the L pad down 3 to 4 notches which really isn't all that much in sound output, they give the same forwardness as the original.

Being that the RSDS dome is stiffer than the original... to me guitar strings sound fuller, you can hear them actually coming from the RSDS polydome if you put your ear to it where as with the original polydome it sounds like it absorbs the strings and you hear more of the sound or detail of the strings coming from the EMIT's.

Piano also sounds better on the RSDS, the keys hit harder and are more natural than that of the original polydome, the RSDS reminds me more of the way my epsilons play piano, with the original polydome you hear the piano more in the EMIT's and the lower mids of the polydome, I think the polydome absorbs up a lot of sound being that it's so soft/absorbent and forgiving.

To me the original polydome is very warm sounding and some people might like that because it makes the speaker more forgiving of the recording.

I also believe that the caps in the polydomes crossover section were chosen to compensate/inhance the sound of the original polydome, the RSDS is a very good replacement if the originals were all gone, the original was designed for the speaker and gives the speaker it's trademark sound, I did a few mods to mine that make it sound even better, Ill post a pic of it, I replaced the super hard flat piece of plastic that was glued on the dome with a soft rigid grey foam and glued it in place with simply speakers speaker glue, I also glued to the magnet behind the dome some of the fill that is behind the polydome in the speaker cabinet to absorb up any reflections that might bounce back through the polydome, my mod makes it sound so much better, very close to the original but better. I still think someone needs to make the originals.
1.JPGUntitled.png IMG_0100.JPG
 
Last edited:
Thanks for that, I actually have two pairs of the RSDS polydomes but I've never looked that closely at them or even removed the grills.
 
Thanks for that, I actually have two pairs of the RSDS polydomes but I've never looked that closely at them or even removed the grills.
I removed the grills just because I felt they looked nicer with them off, don't know how much the grill effects the sound.
 
rsds? I'm unclear on that particular model

oh nevermind, they're the auto midranges.. back in the day My brother had them and the auto emits. I seem to remember they didn't last long as drivers for my hip hop loving brother, I'd suspect he blew them all (mids and tweets) by overdriving them.

Boy, I wish I could go back in time and buy a few sets of them!
 
Thanks for clarification and bonus info ! :thumbsup: I remember now that the rsds comes with that perforated " grill " .( Moot point as they seem unobtanium ). Hopefully mine will last a lot longer as they are but the yellowing progresses .. Sure hope Millerrsound repair service is still there if/when I need it . Hopefully Mr Legall has trained some apprentices that can carry on should he be unable to //:( Maybe at some point it would be a good move to pickup a pair of Cs 3007 or similar( While Im awaiting "My Pair "of Ren 80s ! ) :angel: Greg I found your review enlightening ty . ( Just curious .. Have you ever heard any kappa speakers w mids restored by Millersund ? ) My impression is that if he did it and sat down to compare sound of his placement with orignal and gave it :thumbsup: that's plenty good enough for me ! The one area of the 6.1 that to me sounds not quite as magical is the low midrange .( Although it so completely dependant on the recording ) ( When a really great recording is playing I pretty much want for nothing - Except to keep them just as they are )
 
Thanks for clarification and bonus info ! :thumbsup: I remember now that the rsds comes with that perforated " grill " .( Moot point as they seem unobtanium ). Hopefully mine will last a lot longer as they are but the yellowing progresses .. Sure hope Millerrsound repair service is still there if/when I need it . Hopefully Mr Legall has trained some apprentices that can carry on should he be unable to //:( Maybe at some point it would be a good move to pickup a pair of Cs 3007 or similar( While Im awaiting "My Pair "of Ren 80s ! ) :angel: Greg I found your review enlightening ty . ( Just curious .. Have you ever heard any kappa speakers w mids restored by Millersund ? ) My impression is that if he did it and sat down to compare sound of his placement with orignal and gave it :thumbsup: that's plenty good enough for me ! The one area of the 6.1 that to me sounds not quite as magical is the low midrange .( Although it so completely dependant on the recording ) ( When a really great recording is playing I pretty much want for nothing - Except to keep them just as they are )
I never heard the millersound repaired polydomes, If I had a pair I would surely put them to the test to see how they stack up to the originals
 
Just curious .. Since you have the rsds and (seem) to prefer the sound is there a reason you have not replaced mids in your K9s w them ?? ( Ive heard them in your video think it was a male vocal and ... WOW ! ) Amazing but even though Im listening through K6.1 ..When listening to youtube videos ( with much "better" speakers ) I can actually hear the difference .. They sound like the speakers they are playing :crazy: .> :idea: > :) So much so that when I listen to the Youtube video that Compares Infinity Betas to JM Lab Utopia I can clearly hear the difference and Imo clear superiority of the whole upper range w the betas .
Just realized what a highjack this is .. Sorry OP ..
 
Last edited:
Back
Top Bottom