Infinity Kappa 9s Questions

Namikis

A local seller is offering a pair of these for $1000. The polydomes look milky white so I am aware they will need replaced. The rest looks and sounds good. I am aware that these speakers are tough to drive and have an amp that is 2 ohm stable to handle them.

The questions, for those of you that have experience with them:

1. I am hopeful that with new domes and maybe recapping the cross-overs these speakers will image very well and maybe approach what good modern speakers do in that key are. Is that a fair expectation?
2. Factory polydomes are no longer made, but Vifa appears to make a drop-in replacement. Any experience here using those instead of the originals (I know this is a Polk forum, but checking anyway)
3. Is the price reasonable?

Thanks,

P

Phasewolf

Just because the dome changed color does not mean it's bad unless it does not work leave it alone.

As for the caps they are a costly speaker to recap but are well worth it and those caps are most likely well past there service life.

What amp do you have to drive them because there are places where it can drop to less then a ohm 2 ohms stable may not cut it.

Namikis

Thank you, planning on using an Aragon 2004 if I do get them. I understand this amp can handle them. Other available amps are an Onkyo M-504 and a Sunfire 400x5.

P

halo71

Would love to get a hold of some Kappa 9's! I am not sure about those other amps of yours. But I don't think I would use the M504 on those speakers.

11tsteve

I just rebuilt a set of RSb's. New inductors and caps. Because of the size of the new components, the original crossover boards became useless very quickly, and so I started fresh with new sheets of plastic, a schematic, and learned some point to point wiring. Very fun, and the imaging, pin-point placement, and 3D depth of these littler Infinity's is pretty cool. I have to imaging the Kappa 9s would be very satisfying.
As to the price... I can't really say. What are they worth to you? And tak into account new caps for those extensive cross overs will get pricey....
I found a schematic if you haven't looked.... wowza!

BKphoto

nice grab....they are known as "the amp killers"

Phasewolf

My god if they made a poly cap for the 2000uf if would be the size of a house.

11tsteve

Just the 100 uF for my RSb was bigger than a can of tomatoes... and the low pass coil must have weighed 3 or 4 pounds.... it was a challenge.

bugsnt

Holy Cow - the size of those things are amazing !!

Namikis

11tsteve wrote: »

I just rebuilt a set of RSb's. New inductors and caps. Because of the size of the new components, the original crossover boards became useless very quickly, and so I started fresh with new sheets of plastic, a schematic, and learned some point to point wiring. Very fun, and the imaging, pin-point placement, and 3D depth of these littler Infinity's is pretty cool. I have to imaging the Kappa 9s would be very satisfying.
As to the price... I can't really say. What are they worth to you? And tak into account new caps for those extensive cross overs will get pricey....
I found a schematic if you haven't looked.... wowza!

Holy molly, that is a lot of expensive recapping right there. And that many caps makes you worry about phase issues, even if Arnie is trained as a rocket scientist.

Namikis

Anyone know what the expected life of those pads/pots is? Will they also need replacing? (or bypassing)? Looks like a money-pit!

11tsteve

there were two different designs for my RSb crossovers... the later, simpler one my speaks came with, and the earlier original with a phase shift in the design. I tried the later one first, then re-did them with the original design, which has produced a much more pleasing result.
Originally I tried to bypass the Lpads, using many,many differing values of both Mundorf MOX and Mills 12W. And, to my ears, I could not get them to sound right. I disassembled the Lpads, cleaned them thoroughly, and dropped them back in amongst all of those expensive, beautiful components, and it just seemed right.
However, plenty of people have had good success using resistors... I just couldn't make it happen.
There is no doubt the complexity of these crossovers for the Kappa 9's won't be cheap, but I guess it's up to you to decide the value of such an undertaking.
And maybe it might be worth running past Trey at VR3 mods. There is a possibility he might be interested in such a thing if you don't want to take on the work. If nothing else, he was a big help to me in both knowledge and acquiring materials.

aboroth00

I have owned the Kappa 9's and have recapped them. In extended mode, they reach ~1ohm at <100hz, however in normal mode they're a tad bit easier to drive at ~1.5ohms. There should be a impedance graph somewhere out there. As for the schematics, the caps in the diagram are not always the caps, Infinity used. They would sometimes add caps in parallel or series to get the value they needed.

As for as the midrange goes, the Vifa is not a direct replacement for the Polydome. The Vifa is different in sensitivity and impedance 8ohm vs 4 ohm. The only real replacement for the polydome is another polydome. As far as the appearance goes, as long as its not rigid and still flexible then it has life. If it is opaque and rigid, then it's going to shatter shortly.

If you have the space, money for amps, money for caps, money for the polydomes then its worth it, but buying the Kappa 9's is an investment beyond the actual speakers. The reason they go cheap nowadays is not because they're bad speakers, it's because they require the investment of time and money into amps. I know guys who scrapped the passive crossover, and used an active one instead and a 5ch amp to drive the speakers.

As for as more info the K9's there's much more over on audiokarma where all the old Infinity guys dwell.

aboroth00

Namikis wrote: »

Anyone know what the expected life of those pads/pots is? Will they also need replacing? (or bypassing)? Looks like a money-pit!

Just clean them out.

NJPOLKER

pictures??

KLapinas

I used to sell them and they are a bear to drive. Your best bet is to biamp.

I have a pair of the 8's and they are considerably easier to drive. I run an Aragon 4004 mkii and it definitely does the job. With that said I may be selling them shortly as I have too many toys and I like my Legacy Classics better. I also have a pair of VMPS Supertower/R's that I want to finish rebuilding.