I just picked up a pair of 8 Kappa speakers from my local consignment shop for $50.00. Cabinets and grilles in great shape.
All voice coils check good, but the Polydome mids need need new domes and the 12" woofers are non standard cheepos. All tweeters and mids are very clean.
Anyone know where I can source suitable replacement domes(plastic only)? I fancy my hand at trying to rebuild them before replacing them with non-standard drivers.
I thought maybe a voice coil dust cap if nothing else, might work.
Cheers
Peter
All voice coils check good, but the Polydome mids need need new domes and the 12" woofers are non standard cheepos. All tweeters and mids are very clean.
Anyone know where I can source suitable replacement domes(plastic only)? I fancy my hand at trying to rebuild them before replacing them with non-standard drivers.
I thought maybe a voice coil dust cap if nothing else, might work.
Cheers
Peter
In your instance it would seem you really have just two ways you can go here. 1) Rebuild/Restore you Infinities to original condition.....there are drivers popping up on Ebay all the time to bring your Kappas back to original......however these Infinities and other models are NOTORIOUS for eating amplifiers....drawing immense amounts of current & melting down amps.....even when bi-amped. The funky plastic mid-domes seem to suffer from 'exposure', decompose & crack...there are no simple common or easy repairs possible. The entire units need to be replaced with one that is NOT cracked...but could crack on you two weeks after you spent six months chasing one down..The second choice would be to design a nice three-way within your fixed cabinet volume....it can be done, rather straightforward.
_____________________________________________________Rick......
_____________________________________________________Rick......
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I would only replace drivers with what are supposed to be there if I were you. Kappa's are great speakers! Known to be amp killers though, although the later .1 series (Kappa 8.1) are easier on amps.
I am not 100% positive but I think those Polydomes are fairly rare these days and hard to come by. Check the Infinity forum at Audiokarma.com. I believe there is a thread somewhere there about a guy, I think in China, that sells replacement diaphragms for that mid.
I am not 100% positive but I think those Polydomes are fairly rare these days and hard to come by. Check the Infinity forum at Audiokarma.com. I believe there is a thread somewhere there about a guy, I think in China, that sells replacement diaphragms for that mid.
I have never heard an Infinity Kappa and I bought these to play with and to hear why they are highly regarded(at least, by some). All of my speakers are DIY jobbbies, and this one may wind up having alternative drivers installed, since I have small supply of woofers, etc.
I assume the amp melting problem is associated with the woofer circuit, and I am thinking of bypassing that circuit and use a couple of subwoofer plate amps with Dayton drivers that I already have- just to get them up and running.
The poly midrange replacement may be a problem. I have one Dayton 2" mid to try, but have no idea how it compares sonically to the original polydome- and that is where the essence of the music lies.
Next step - check out the crossovers.
Thanks for the comments.
Peter
I assume the amp melting problem is associated with the woofer circuit, and I am thinking of bypassing that circuit and use a couple of subwoofer plate amps with Dayton drivers that I already have- just to get them up and running.
The poly midrange replacement may be a problem. I have one Dayton 2" mid to try, but have no idea how it compares sonically to the original polydome- and that is where the essence of the music lies.
Next step - check out the crossovers.
Thanks for the comments.
Peter
The Kappa 8s and 9s as well as any of the higher Infinity models were hard on amps that couldn't handle low impedances (as low as 2 ohms).
I personally have powered them with various Haflers, Thresholds and even a Class D amp, and my buddy has Parasound amps that also work well with those.
I still have a set of 8s in Santos, instead of the usual Oak, and they are one of my all time favorite speakers, even more than the 9s (buddy has 8s and 9s).
If you can get oem replacement drivers for them, it would be worth it as they are nice speakers.
Good deal on those, I paid over $3000 Cdn for mine back in the late 80s.
I personally have powered them with various Haflers, Thresholds and even a Class D amp, and my buddy has Parasound amps that also work well with those.
I still have a set of 8s in Santos, instead of the usual Oak, and they are one of my all time favorite speakers, even more than the 9s (buddy has 8s and 9s).
If you can get oem replacement drivers for them, it would be worth it as they are nice speakers.
Good deal on those, I paid over $3000 Cdn for mine back in the late 80s.
Kappa 8 midrange
Anyone know the sensitivity rating of the 3" polydome?
I have a couple of 3 " drivers in my collection to try out to evaluate the Kappas.
One is the Tang Band bamboo cone 86db- the other is Dayton 2" dome 89db.
Still evaluating polydome repair or replacement.
Santa is bringing me the proper woofers.
Peter
Anyone know the sensitivity rating of the 3" polydome?
I have a couple of 3 " drivers in my collection to try out to evaluate the Kappas.
One is the Tang Band bamboo cone 86db- the other is Dayton 2" dome 89db.
Still evaluating polydome repair or replacement.
Santa is bringing me the proper woofers.
Peter
Hi Peter, not sure if you have seen this or not, but here it is in case you haven't.
http://www.infinity-classics.de/technik/manuals/Kappa_8_technical_sheet.pdf
The site has lots of good Infinity speaker specs, photos, schematics etc.
It is German, but it has a lot of english content on it, for everything else, you can use an online German to English translator.
Good Infinity pics as well on (late) Bobby Shreds site and Davids Audio.
http://www.infinity-classics.de/technik/manuals/Kappa_8_technical_sheet.pdf
The site has lots of good Infinity speaker specs, photos, schematics etc.
It is German, but it has a lot of english content on it, for everything else, you can use an online German to English translator.
Good Infinity pics as well on (late) Bobby Shreds site and Davids Audio.
Problem is, with the bamboo cone, you would have to build a sub-enclosure & you'll wind up butchering the larger enclosure to "install" the sub-enclosure. so that's a non-starter. The two inch dome might not reach down far enough (roll off) to match-up with the woofer. There is an exact replacement thru Orange County Speaker for the dome...at $130, then there is the Tang-band 3" mid dome..at $135.....that TB dome runs at 90Db....I'd bet that is a high enough sensitivity.
Try your 2"....listen carefully for any frequency drop-outs, esp on the bottom end as it crosses to your woofer/s.
Thank-you Santa!
____________________________________________________Rick....
Try your 2"....listen carefully for any frequency drop-outs, esp on the bottom end as it crosses to your woofer/s.
Thank-you Santa!
____________________________________________________Rick....
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If you click on the Kappa 8 link, it shows the model in Oak & Santos:
Infinity Kappa Serie
There is a 2 page testing results and review from Hirsch-Houck Labs at the bottom of the page, that may have some information you can use.
Infinity Kappa Serie
There is a 2 page testing results and review from Hirsch-Houck Labs at the bottom of the page, that may have some information you can use.
Thank you Guys....
Some good info there.
Richard, the midrange drivers have separate enclosures already, so the 3" TB may work.
I really like the presentation of them, so I'll give them a try. This to me, is the fun part of DIY. I only wish that I had a decent polydome to compare.
I certainly don't intend to butcher the cabinets.
Peter
Some good info there.
Richard, the midrange drivers have separate enclosures already, so the 3" TB may work.
I really like the presentation of them, so I'll give them a try. This to me, is the fun part of DIY. I only wish that I had a decent polydome to compare.
I certainly don't intend to butcher the cabinets.
Peter
Just installed a bamboo driver in place of the poly on a home made adapter plate made from Masonite on one of the Kappas. With the controls set on Norm, the initial impression using my iPod into a NAP140 clone is very good. Twiddling the midrange controls bring about a surprisingly big change and one of the pots is scratchy when moving it, but seems OK at the norm position.
Wonder if they can be cleaned?
All this in the workshop- I guess 2 of us will have to move them to the music room soon and do some serious testing.
Wonder if they can be cleaned?
All this in the workshop- I guess 2 of us will have to move them to the music room soon and do some serious testing.
Congrats on your fix......I always wondered how these trick FR drivers with their phase-plugs, weird cone materials & all, would do for mid-range duty. One would tend to think they just might outperform so-called dedicated mid drivers.
________________________________________________Rick............
________________________________________________Rick............
Pics to follow....
One of the rear emits is not putting out, so suspect a problem in the crossover.
Installed the TB 3" driver in the second cabinet, lugged them into the music room, which now looks like a second hand hi-fi store.
No woofers yet- may try the 10" Dayton subs that I have in other 3way enclosures.
Connected my Starfish pre to the F5 clone and I must say, these Kappas are sweet.
Can't imagine how they will sound biamped with my Symasym amps, or maybe leave the F5 to run the upper drivers as it is right now.
One of the rear emits is not putting out, so suspect a problem in the crossover.
Installed the TB 3" driver in the second cabinet, lugged them into the music room, which now looks like a second hand hi-fi store.
No woofers yet- may try the 10" Dayton subs that I have in other 3way enclosures.
Connected my Starfish pre to the F5 clone and I must say, these Kappas are sweet.
Can't imagine how they will sound biamped with my Symasym amps, or maybe leave the F5 to run the upper drivers as it is right now.
Happy to hear that, they are too nice for that
Wouldn't mind seeing some crossover pics too if you get a chance.
Considering the woofer crossover mod myself.
I'll have to hear how the woofers are before I pass judgement on the mod.
It's a very simple "fix" - takes more time to pull the crossover through the woofer aperture than to solder one 1" jumper across one of the caps and unsolder one side of the 12mh inductor.
Next time I pull the crossover, I'll take a pic, though you may have it done by then.
Right now I'm busy listening.
It's a very simple "fix" - takes more time to pull the crossover through the woofer aperture than to solder one 1" jumper across one of the caps and unsolder one side of the 12mh inductor.
Next time I pull the crossover, I'll take a pic, though you may have it done by then.
Right now I'm busy listening.
Here are pics of the upper drivers with the 3" bamboo mounted on a masonite adapter. Excuse the dusty polygraph!
Also a poor pic of the solid oak pedastal I made to replace the shoddy originals.
Now have the Dynaco subs hooked up with a minidsp equalizing and getting rid of the room bloom - highly necessary in my room with any woofer. If the stock woofer does better than this I shall be very surprised. Flat down to 30Hz in a 1.2cuft sealed cabinet.
Peter
Also a poor pic of the solid oak pedastal I made to replace the shoddy originals.
Now have the Dynaco subs hooked up with a minidsp equalizing and getting rid of the room bloom - highly necessary in my room with any woofer. If the stock woofer does better than this I shall be very surprised. Flat down to 30Hz in a 1.2cuft sealed cabinet.
Peter
Attachments
Nice work on the replacement driver, and the solid oak bases are a nice upgrade too.
My 8s are across town at my brothers place, was hoping to get a glance at the crossover before I brought what I needed over there to mod them.
Those things are too big and heavy to lug all over the place, plus not willing to risk damaging them in the back of a truck in -30c weather.
My 8s are across town at my brothers place, was hoping to get a glance at the crossover before I brought what I needed over there to mod them.
Those things are too big and heavy to lug all over the place, plus not willing to risk damaging them in the back of a truck in -30c weather.
All you need to do the crossover mod, after the crossover is out, is a 1" long small gauge wire per speaker(a piece of resistor or capacitor lead is fine - I save some of those cut offs just in case),
and an iron and solder, of course. The cap to be jumpered and inductor to be clipped or un soldered are right on top of the board-very accessible.
If you do it, let me know how it turns out. I'm still waiting for Santa to bring my woofers.
PKI...Can you describe the improvements with the Vifa dome? I see Madisound has them in stock.
Peter
and an iron and solder, of course. The cap to be jumpered and inductor to be clipped or un soldered are right on top of the board-very accessible.
If you do it, let me know how it turns out. I'm still waiting for Santa to bring my woofers.
PKI...Can you describe the improvements with the Vifa dome? I see Madisound has them in stock.
Peter