XKi - X's ab initio Karlson 6th Order Bandpass

I have a non dimensional curve fit of the K aperture here:

https://www.diyaudio.com/forums/full-range/213594-karlson-10.html#post3528706

The curve fit of the K-slot is quite accurate when I compared it to the prescribed numbers. The fit is given by Y=0.974X^2+0.00874X+0.0207. This is for X=[0,1] and Y=[0,1]. Simply scale function for any slot based on max height and width at Y(X=1).

It’s the function I use in my Akabak model of the slot.
 
Hi all ,

i have a set of W5-2143 in a tabaq and i'm not convinced , that's very good for the money , no doubt buy way behind the FH3 FE126En i made for my son

I plan to have a draft try in Xki karlsonator ( i have a DDRC24 for tuning so i don't worry about the BSC circuit )

Having said that , i have spend 2-3 hours reading about the Xki and the reviews makes me think i must try

Now i can build super fast prototype in draft style
hardware to use ?
Xps 20mm ?
12mm plywood ?
 
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Hi X,

regarding your Akabak model, might you "easily" modify it to toggle between the usual slot vs an "exponential" - slower opening aperture to see if there are cases where the slower might have an advantage ?

I'd expect the slower opening generally to tune a bit lower for system tuning and for front chamber tuning (?)
 
Hi all ,

i have a set of W5-2143 in a tabaq and i'm not convinced , that's very good for the money , no doubt buy way behind the FH3 FE126En i made for my son

I plan to have a draft try in Xki karlsonator ( i have a DDRC24 for tuning so i don't worry about the BSC circuit )

Having said that , i have spend 2-3 hours reading about the Xki and the reviews makes me think i must try

Now i can build super fast prototype in draft style
hardware to use ?
Xps 20mm ?
12mm plywood ?

Speedy build is best with XPS foam construction. Least risk of spending too much time or money on materials.
 
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Just found 12mm construction panels on the way to the house , let's go 🙂

Thanks
 
How does one get a reasonably square edge with XPS foam board? - when scored and snapped, it tends to sometimes curl a bit. -- don't know what would cut if square. Also, what cements work best ?

I've only played with the 25mm thick stuff. It would be fun to make say a Klipsch Belle midbass horn that could be used outdoors without worries - or maybe a 15" driver XKi tuned for "kick".
 
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That’s an ideal material combo. Use a semi pliable adhesive between the XPS and wood and you have a constrained layer damping (CLD) panel with foam damped walls. Really an advanced composite ideal for speaker building. It will best BB plywood in sound quality.

There is special construction adhesive for XPS foam. I think a variant of PL Premium works. As well as Liquid Nails (non VOC). These are in the US. In Europe look for something that doesn’t have VOCs as that melts the foam.
 
Thin plywood would protect the foamboard from dents. What type circular saw blade / tooth # cuts XPS without binding and kick-back?

I cut XPS using a circular saw and it cuts like butter, no concern for kickbacks. It does make a lot of small pink dust particles which sticks to things quite well, maybe due to static electricity.

In the US a less expensive adhesive which remains forever plyable as a constrained layer, is Roberts 3095. It is a carpet adhesive. I don't think that it remains quite as gooy as green glue, but it is a lot cheaper. And if you don't use it all, you can use it for your carpet install.
 
I got some banana plugs off ebay for the amp ends of speaker wire. I am using spring clips on the speaker boxes so I will tin the wires on that end. I am thinking of using Dollar Tree extension cords for wire (cheaper than by the foot at Lowes or Ace). I am getting close to finishing my hybrids (similar to post #7 on page 1).

I am using foam core for the ducts and am going to try electric scissors for cutting the board. I have used them for vinyl tile with good result and think I tried them on a scrap piece of foam core some time back.
 
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