InfinityKappa 9usedInfinity Kappa 9Infinity Kappa 9 Speakers – Fully restored, updated and WAY, WAY better than new! With 200+ hours invested, these Kappa 9s were rebuilt and restored by a veteran 30-year audio engineer and woodwor...7950.00

Infinity Kappa 9 [Expired]

no longer for sale

Infinity Kappa 9 Speakers – Fully restored, updated and WAY, WAY better than new!

With 200+ hours invested, these Kappa 9s were rebuilt and restored by a veteran 30-year audio engineer and woodworker. They look, sound and perform way better than new, within significant improvements in both crossover design and cabinet construction. Please refer to the pics for more detail.  

The Cabinetry

Purchased by me new in 1991 and in storage for the last 25 years, the project began by taking the cabinets down to “bare metal” including removing rounded edge “wooden heatsinks” altogether. The original cabinets were not air tight whatsoever- requiring that literally every seam required filling, chalking and sealing. Next, the cabinets were carefully veneered in Bubinga wood, then applying 4 layers of professional satin conversion lacquer. Though not required for use, new black base plates were created and are removable. Note that during the process, there are 2 minor flaws (Shown in Photo) however they are at the very backside bottom of the cabinets. The grill cloth was upgraded and replaced as well.

The Drivers

The Poly Domes were completely rebuilt by Miller Sound and the woofers were re-foamed with new dust caps applied. The Mid-bass, Semits and Emits are factory original and perform perfectly. All of the drivers had foam sealing material applied to ensure a true air-tight (tight bass control) cabinet.

The Crossovers

The heart of any speaker system. Kappa 9s are well known for being inefficient and loads dipping below 1 ohm, which will toast most amplifiers. This was due to the fact that Infinity original design had an inexpensive 20 gauge, 15mh transformer type coil directly across the low pass connection (See pics).

In addition to stress on the amplifier, loads this low also reduce the amplifier’s damping factor which can muddy the bass.  My guess was they took this approach to better control the woofers to compensate for the massively air-leaking cabinet construction – they eventually abandoned this approach in later designs.  The bass crossover component is now a 6db/Oct 12ga., 13mh coil.  The remaining crossover design was faithfully recreated utilizing only high-grade Audyn German capacitors. The original capacitors were incredibly low-grade. (In addition to the poor quality, most all capacitors deteriorate over time, so any speaker of this age would absolutely require replacement).

The original crossover coils were either 20ga wire wound or iron core which can saturate/distort the audio signal, plus their placement was also extremely close which can introduce audio cross-talk. All of the coils were upgraded to air core and increased wire gauge for improved efficiency and sound resolution. They were also properly distanced and placed on different dimensional planes. The speaker plugs posts were upgraded to high quality, 5-way binding posts. The crossover materials ALONE were $1,000.00+ and required 60+ hours of meticulous effort.  

The sound:

You’ve never heard Kappas 9s EVER sound this good AND just about any amp can now drive them. The bass is simply incredible, with the mids and highs transparent without fatiguing. If you’re a Kappa fanatic, these are nirvana. 

With over $5000.00 of hard costs and 200+ painstaking hours invested, they compare to speakers in the $25k range.  


USA ONLY! – Flat $500. Will be shipped in custom-built crates/boxed via FedEx Ground. These are heavy; each weighs approximately 130 lbs./each


bradmich member since February 2018

Last 12 months
Items from this seller