Dual Infinity Kappa 120.9w build

[jinjuku]

This is a sub build utilizing the Infinity Kappa 120.9w. The total price is going to end up being $360. This is partially achieved by routinely scouring the likes of Craigslist, Amazon, Guitar Center's used section.

Picked up the Crown XLS 602D for $129 shipped:D and Behringer FBD 1124 for $62. The Amp was from a private seller on Amazon and I consider myself incredibly lucky for having snatched it up. The Behringer was from Guitar Center in El Paso for $39 + $10 for 1 year warranty + $13 to ship. The employee in the El Paso was extremely service oriented. Double checked on the unit and took the order over the phone.

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

The port sides are cut out of a solid piece using the table saw, Rockwell VersaCut (great little handheld circ-saw) and router table.

As you can see the port is mechanically strong. One of sub boxes is already ~45-50 lbs is on top.

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

All edges (besides the baffle facing edge) are dado'd.

Cross brace is .75 X 3 inches with wood glue and 5-6 brads per side. That definitely stiffened up the cabinet.

[Mayhem13]

Re: Dual Infinity Kappa 120.9w build

I hope those drivers sound as good as they look.....That's about the best looking sub i've ever seen.:D

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

I hope those drivers sound as good as they look.....That's about the best looking sub i've ever seen.:D

They are supposed to be a really low distortion, high power handling sub. Here is WmAx on the matter:

The potential output of one of these is so great, that it would be very similar to a PB13 Ultra, except that the PB13 would not have as much output in the lowest range, because the port on Andrew's design offers less compression due to the large cross section area, and the PB13 would potentially offer greater output by some degree, in the higher octaves, because of it's larger cone surface radiation area. But to realize the output potential of the Kappa Perfect cabinet design above, you would need to use a bridged EP2500 to deliver sufficient peak power. However, one does not need this level of capability in actual use. It's overkill. However, stereo units are always going to provide better ability to integrate with the main speakers, even if you don't need the output ability that is possible.

Not that we are driving with dual EP2500's or the like.

[jinjuku]

SPL vs Frequency at 400 watts

The amp that is driving this will have a little more head-room:

This is Andrews (Avaserfi) simulation

[Mayhem13]

Re: Dual Infinity Kappa 120.9w build

I simmed it in Unibox after seeing your thread and my sims look pretty much identical to the WinISD plots you show. I might pick up a pair of these to mess with.

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

You might want to simulate the Infinity Reference 1260w (4ohm) and 1262w (8 or 2 ohm) also.

[johnnyrichards]

Re: Dual Infinity Kappa 120.9w build

So is the Kappa otherwise the same as the Perfect? Looks like an entirely new design from the Perfect and Perfect VQ drivers.

Yes, the Reference subs model really well for home use

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

So is the Kappa otherwise the same as the Perfect? Looks like an entirely new design from the Perfect and Perfect VQ drivers.

Yes, the Reference subs model really well for home use

It's a drop in replacement from what everyone has said. The Reference 1260W is $50-$60... :D

I might have to get one or two in and play around with those. The idea that for ~$360 I can produce in my garage something that will run with or possibly out perform the SVS PB 13 Ultra (the old one)at $2K is just mind boggling. I know one member built the Kappas and just one bested his EP600 Axiom sub that was $1800 at the time. He said two was simply no competition.

I wonder how the Kappa performs against the Titanic MK III 12 in same size enclosure.

[greywarden]

Re: Dual Infinity Kappa 120.9w build

I built 2 sealed boxes for my buddy's car back in the day for (2) 12" Kappa Perfects and Infinity's biggest amplifier, and WOW did it sound amazing.

[johnnyrichards]

Re: Dual Infinity Kappa 120.9w build

It's a drop in replacement from what everyone has said. The Reference 1260W is $50-$60... :D

I might have to get one or two in and play around with those. The idea that for ~$360 I can produce in my garage something that will run with or possibly out perform the SVS PB 13 Ultra (the old one)at $2K is just mind boggling. I know one member built the Kappas and just one bested his EP600 Axiom sub that was $1800 at the time. He said two was simply no competition.

I wonder how the Kappa performs against the Titanic MK III 12 in same size enclosure.

My money would be on the Kappa

I have a pair of Reference 8" in my car, and really like them, all things considered. The drawbacks are related to the 8" diameter, but I rarely turn it up to 7 anymore, much less 11. I used to have a pair of 10" Kappa Perfect with a 400W mono block amp, but that was just too much for me these days. Two 8" with 250 watts is a nice compromise for me.

[fastbike1]

Re: Dual Infinity Kappa 120.9w build

You (and Johnny) are right about that. The 1260 looks crazy good sealed 36Liters, 300 watts 109dB F3/F10 36/23 under xmax all freq.

If you have the power, this is wild for $56.

You might want to simulate the Infinity Reference 1260w (4ohm) and 1262w (8 or 2 ohm) also.

[ROTECH]

Re: Dual Infinity Kappa 120.9w build

+1 for the infinity autosound subs. Having spent close to $100k (retail cost not my cost) in car audio over my years... The best sounding sub I ever ended up using was the 10'' infinity kappa perfect circa 2002. I ran 3-10's sealed with 1200w rms, and wanna talk about musical, clean yet still deep for a rather low xmax sub.

The price point on these cannot be beat. I am eagerly waiting to hear your results. Thanks for this build man....

[jinjuku]

Re: Dual Infinity Kappa 120.9w build

Yep, the 1260 is REALLY starting to get my mouth watering for the price.

Some more build pics. The baffle is 3/4" ply inset and 1 1/8th" MDF. That was a lot of cutting. The spiral up cut bit did a great job but couldn't quite reach. So I had to finish it off with a jigsaw.

These will most likely weigh in at 105 when all is said and done.