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Infinity Kappa 8 modification
Infinity Kappa 8 modification
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Old 25th February 2012, 09:16 PM   #1
grapple is offline grapple
diyAudio Member
Join Date: Jul 2011
Default Infinity Kappa 8 modification

Have had some excellent Infinity Kappa 8's for some time now and they sound great but are so hard to drive its killing me. I have driven them with an Adcom 555, a Carver M1.0t, and also biamped them with these amps as well. On tracks on Jesse Cooks "Freefall" album (tracks 4, 6, 8) there are some powerful lows that will test any amp driving these Kappas.

Enter my new Emotiva XPA-2 rated at 500w into 4 ohms. It drives these speakers very well but on Jesse Cooks "Freefall" song on the Freefall album, the amp shuts down into protection mode at high volumes. I have heard that on some low frequencies, the Kappas will fall to 1 ohm. This particular track has very powerful lows and would probably test any amp on these Kappas. The question is.... can the Kappas be helped?

I am posting this because I know there are many very savvy techies on this forum. I came across a suggested Kappa 8 modification on another forum and wanted to runn it by you experts. I am sooo not an electronics guy but want to know if this would be a suggestion. The quote on the mod is as follows:

"As a long time Kappa 8 owner I can strongly recommend a simple bypass modification to the crossover that makes the speaker easy to drive and actually better with a more natural and full bass response. Simply unsolder or cut one side of the 12.5 mh coil from the crossover and solder in a shorting bridge across any one of the three 500uf (1500uf total) capacitors that are the first thing after the woofer binding posts. This takes the 'reactor' out of the woofer circuit. Now your amp will just see a common 4 ohm load and the bass will be very natural without the 'thump' where that cap and coil reactor stores a charge and throws it at the woofer while melting your amp in the process. I listened carefully using the famous Hok-Man Yim Poem of Chinese drum CD and it actually hits harder with better decay after the mod and the amp doesn't overheat in the slightest. The Kappa 8's punch that track harder than anything I have owned with just one 12 per side. If you want to keep protection against a DC short from your amp, ignore shorting out the (series) capacitor, but by all means get that evil 12.5 mh (shunt) coil out of the woofer circuit."

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Old 8th May 2016, 09:59 AM   #2
markolino72 is offline markolino72
Join Date: Jun 2015
Default kappa 8 amplification

THRESHOLD vintage amp
is the key
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Old 8th May 2016, 10:00 AM   #3
markolino72 is offline markolino72
Join Date: Jun 2015
find a threshold vintage amp...
such as a 400a or a stasis 3 or 2 etc...
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