Simple 12" Infinity Kappa VQ MidQ Plans

[avaserfi]

Due to a large amount of requests I have spent some time designing a simple version of my Infinity Kappa VQ Build. These plans would likely be easily completed by someone with wood working experience in less than one day. A novice would probably want to take more time, but shouldn't have much trouble with this design.

The graphs:

Transfer function:


SPL versus frequency at 400 watts:



Cone excursion at 400 watts:


Cone excursion with recommended 20Hz 2nd order highpass at 400 watts:


Port airspeed at 400 watts:


The CAD design:


The cabinet is 22.5" wide x 22.5" deep x 25" tall with a port that measures 12.5" wide x 55" long x 3" tall.

With the top taken off:


Front baffle and top taken off:


Side taken off as well:


One cross brace removed as well:


Cut list (Use 3/4" cabinet grade plywood):

Front baffle: 21" x 24"
Rear baffle: 22.5" x 24"
Sides: 21.75" x 24"
Top/Bottom: 22.5" x 22.5"
Cross brace (large): 16.5" x 21"
Cross brace (small): 6.25" x 21"
Port bottom:
2x 18" x 3"
17.25" x 14"
Port back:
2x 24" x 3"
18" x 14"
Port top:
2x 13.75" x 3"
13" x 14"

You will want to get some OC705 or 8lb Rock wool to place inside the cabinet. Use a 4" piece wrapped in cloth (to eliminate chances of pieces being blown out the port) and glue it (using 3m Spray 77) to the large brace.

Recommended amplifier EP2500.

Thats everything. Optional things you can do to increase sound quality:

1) Round over/cove the port corners with a router. This will decrease air turbulence and minimize chances of port noise/compression at high SPL.

2) Integrate the unit with a DCX2496. This will also allow for equalization of your subwoofer for maximum perceived sound quality.

3) Build 2 and integrate as a stereo pair with the DCX.

**Please note I make no guarantees about actual performance as there are a variety of factors that effect such a unit.***

[Sonnie]

Do you have any pics of the finished product... as well as any measurements you have taken?

[avaserfi]

Sonnie wrote:

Do you have any pics of the finished product... as well as any measurements you have taken?

This design is actually a simplified version of my previous build images are found here. It models exactly the same as previously shown. With an EP2500 bridged into a single woofer corner loaded I was able to produce 120dB at 20Hz in my 13x18x8 foot room. Except for minor (depending on application) differences between the designs they will produce almost exactly the same audible response.

[avaserfi]

There has been one build that has taken place so far a thread here. The user finished his pair today and is extremely happy. The user claims they both sound good and with the pair his is running 20-30Hz sweeps at about 125dB with a single EP2500 powering both subs and no audible distortion. He says there is more to give but is scared to destroy his house. He will be posting a review soon enough and I will quote it here as well.

With my build and a single bridged EP2500 I was able to achieve 120dB with no audible distortion [corner loaded] with a single Kappa VQ of this caliber...

As andrew has stated I am very happy with the performance of these subs. I was not sure what to expect but I have been extremely pleased with what i am getting out of these so far. They play very cleanly and have got more capabilities than I can see myself needing. I was getting 124db at what I think is around 23-20hz and really did not want to turn it up even more to see just how loud I could go because I dont want to find out their limits the hard way. I already could feel the floor flexing and the doors were rattling in the jambs so hard I couldnt make them stop by even holding them so yeah... Thats pretty much passing with flying colors in my book.

Im working on getting this REW software working (feedback issues with both my desktop running an audigy2 and my apple powerbook) and then I can start playing with the crossover a bit more and the EQ on the Behringer DCX2496 and then I can really take full advantage of what these have to offer, as well as the DCX.

These are definetly better than the Axiom EP600 that I have also used in my system and will bring back up here to do a more formal review of these as a comparison as its the only worthy subwoofer I have access to.

[avaserfi]

Haoleb has asked me to post his review here since he has too few posts to post it himself. Please note I have no affiliation with this user he simply the first of which I am aware who followed my detailed plans.

Find the subjective review here: http://forums.audioholics.com/forums/showthread.php?t=46071