Bradmich
New Member
Hello fellow audio heads! - thought you might enjoy seeing my latest project. I think I might make a whopping $6/hour rebuilding these....Labor of love 
Kappa 9’s 2019 - They look, sound and perform way better than new, within significant improvements on both the crossover design and cabinet construction. See pics.
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” including removing what I call the rounded “wooden heat-sinks” altogether. The original cabinets were not air tight whatsoever- requiring that literally every seam required filling, chalking and sealing. (If you have a pair- don't bother just sealing the drivers- they leak like the Titanic- everywhere). Next, the cabinets were 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. 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 – As I understand it, 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 crosstalk. 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 crossover materials ALONE were over $1,000.00 and required 60+ hours of meticulous effort.
The sound:
OMG! For a FACT, you’ve never heard Kappas 9s EVER sound this good AND just about any amp can now drive them - it's a mind bender. If you’re a Kappa fanatic, these are nirvana. For me, it’s onto a new project and am selling them.
Enjoy!
Kappa 9’s 2019 - They look, sound and perform way better than new, within significant improvements on both the crossover design and cabinet construction. See pics.
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” including removing what I call the rounded “wooden heat-sinks” altogether. The original cabinets were not air tight whatsoever- requiring that literally every seam required filling, chalking and sealing. (If you have a pair- don't bother just sealing the drivers- they leak like the Titanic- everywhere). Next, the cabinets were 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. 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 – As I understand it, 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 crosstalk. 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 crossover materials ALONE were over $1,000.00 and required 60+ hours of meticulous effort.
The sound:
OMG! For a FACT, you’ve never heard Kappas 9s EVER sound this good AND just about any amp can now drive them - it's a mind bender. If you’re a Kappa fanatic, these are nirvana. For me, it’s onto a new project and am selling them.
Enjoy!
You d'man. Simply beautiful. 
