I did repair the original polydomes using a 3" doped paper dust cap and they worked well, but I have no idea how they compare to unspoiled polydomes. The TBs are the best so far and with my minidsp I can readily correct anomalies in FR, but strangely the little bamboo drivers blend right in with the stock crossover adjustment.
The Kappas are the first "big sounding" speakers I have had and something like double basses sound very convincing, but they handle delicate stuff well, too.
You are right about choosing between trade-offs.
I have at the moment, three sets of speakers and I could listen to any of them for a long time.
Kappa 8
Apogee Centaurs(modified ported enclosure-diy)
Diy waveguideTMM using Peerless nomex woofers and XT25 tweeters.
All have their benefits and drawbacks and all sound different even though the FRs are much the same.
Isn't it a fun hobby? Maybe a bit like playing golf. Exacting and frustrating.
Peter
The Kappas are the first "big sounding" speakers I have had and something like double basses sound very convincing, but they handle delicate stuff well, too.
You are right about choosing between trade-offs.
I have at the moment, three sets of speakers and I could listen to any of them for a long time.
Kappa 8
Apogee Centaurs(modified ported enclosure-diy)
Diy waveguideTMM using Peerless nomex woofers and XT25 tweeters.
All have their benefits and drawbacks and all sound different even though the FRs are much the same.
Isn't it a fun hobby? Maybe a bit like playing golf. Exacting and frustrating.
Peter
I´m trying to rescue my Kappa 8 too.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Infinity Reference Standart Series RS-8 Kappa
Because high distortion and weak bass transmission of most amplifiers I have check the schematic from low pass section of the crossover network - go to the attachment.
I can't understand how to choose such a design.
1.400µF NP capacitor (composed of two blue 700µF ones in very small sizes) and inductors in transformer design. A desaster for most amplifier models, extremly low impedance minimun - go to attachment and post #4 under
https://www.diyaudio.com/forums/full-range/207548-infinity-kappa-8-modification.html#post6108665
and often exploded caps is the consequence.
I cut the rail between the "+" input terminal and the input of low pass filter (pins of 2x700µF) and desolder the "+" cable of bass transducer from low pass filter output for connection directly to the "+" terminal
Because a bi-amping mode was already present only an active crossover was introduced. I choose this version from Behringer (cut-off range between 90-900Hz):
Behringer CX2300 replace caps (values change)
Together with NAD's power amplifier 208 under
Spezialanfertigung für meine Neue NAD 208 THX, Verstärker/Receiver - HIFI-FORUM
and
NAD 208 POWER AMPLIFIER Service Manual download, schematics, eeprom, repair info for electronics experts
now excellent sonic results.
Because high distortion and weak bass transmission of most amplifiers I have check the schematic from low pass section of the crossover network - go to the attachment.
I can't understand how to choose such a design.
1.400µF NP capacitor (composed of two blue 700µF ones in very small sizes) and inductors in transformer design. A desaster for most amplifier models, extremly low impedance minimun - go to attachment and post #4 under
https://www.diyaudio.com/forums/full-range/207548-infinity-kappa-8-modification.html#post6108665
and often exploded caps is the consequence.
I cut the rail between the "+" input terminal and the input of low pass filter (pins of 2x700µF) and desolder the "+" cable of bass transducer from low pass filter output for connection directly to the "+" terminal
Because a bi-amping mode was already present only an active crossover was introduced. I choose this version from Behringer (cut-off range between 90-900Hz):
Behringer CX2300 replace caps (values change)
Together with NAD's power amplifier 208 under
Spezialanfertigung für meine Neue NAD 208 THX, Verstärker/Receiver - HIFI-FORUM
and
NAD 208 POWER AMPLIFIER Service Manual download, schematics, eeprom, repair info for electronics experts
now excellent sonic results.
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in the attachment the associated images:
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I know this is an old thread, but I’m curious did this work for you? I’m purchasing a used pair of K8’s in a couple weeks and this is a concern of mine. Many up years ago I had a pair of K9’s, brand new and I had a rough time driving them. In fact, they were a total pia to set up as well. Do to the headaches, I traded them shortly after. It may have been the equipment but if this mod worked, I may do it right off the bat. Also, if it worked, did it affect bass performance at all?
I wanted to do it, but just dont have time at the moment. Can you please install VituixCAD or another XO sim software and make the speaker XO in there. After you do that can you please post the filter gain curves here. We can suggest you how to do something with the XO without altering the response to much, but hopefully can help to improve the impedance. You can of course can play with the simulations yourself and see what you can come up with.
that what I used to drive them with 
