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Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 7:25 am
by HAL
A friend found a pair of Infinity Kappa 8 speakers that need the Polydome K's and 12in woofers rebuilt. I picked them up awhile ago. Not going to complain for $80/pair.

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These are the original version 4-way speaker with the bipole EMIT planar tweeters, Polydome K, Polygraph K dome and 12in woofer.
Found out that Miller Sound in PA does the rebuilds, so hope to be dropping them off this weekend.
Will post pictures of the process along the way of replacing the passive crossover with the DSP crossover from measurements.
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 8:20 am
by brombo
Which DSP crossover are you using?
I found this review which might be of interest -
https://www.youtube.com/watch?v=3t4DXio ... haelAndrew
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 8:29 am
by HAL
Using the Danville Signal dspNexus 2x8 DSP processor:
https://www.danvillesignal.com/dspnexus ... -processorThanks for the video! Will give it a look!

Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 2:14 pm
by tomp
Great speaker but the 90 Hz crossover point will put a lot of strain on the 5" lower mid driver. I'd try a 200 Hz crossover with the Nexus which should improve dynamic capabilities. The 12" woofer will still be omni at that frequency.
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 3:43 pm
by HAL
Tom,
Thanks for the suggestion!
Already have a prototype DSP crossover ready, so will update it with the suggested XO for the 12in and 5in drivers.
Rich
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 15th, 2024, 3:53 pm
by HAL
The beginning of the Infinity Kappa 8 DSP crossover design with DSP Concepts Audio Weaver for the dspNexus 2x8.
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 20th, 2024, 9:49 pm
by HAL
Dropped off the two Polydome K mid ranges and two 12in woofers for refoam at Millersound in PA for rebuilds.
They took a look and said they were in great shape for rebuilding, so will be a few weeks before they are shipped back.
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 28th, 2024, 8:51 pm
by HAL
Parts to mod the Kappa 8's are arriving. Going to use Belden 1309A 14awg stranded cable to each driver that is already here.
Hope to hear about the Polydome K midrange and 12in woofer driver repairs by this weekend.
Some Parts-Express binding posts to add enough pairs for each driver in the speakers. Will be paralleling the two EMIT tweeters to make a bipole radiation pattern. The original design seems to be an ambience tweeter in phase with the front driver.
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 29th, 2024, 2:40 pm
by Roscoe Primrose
HAL wrote:Parts to mod the Kappa 8's are arriving. Going to use Belden 1309A 14awg stranded cable to each driver that is already here.
Hope to hear about the Polydome K midrange and 12in woofer driver repairs by this weekend.
Some Parts-Express binding posts to add enough pairs for each driver in the speakers. Will be paralleling the two EMIT tweeters to make a bipole radiation pattern. The original design seems to be an ambience tweeter in phase with the front driver.

Be careful with those if you're using banana plugs, these have to be screwed down tight to get a good connection even with banana plugs...
Roscoe
Re: Infinity Kappa 8 speaker rebuild with DSP crossover
Posted: May 29th, 2024, 3:35 pm
by HAL
Roscoe,
Thanks! Will do!
Rich