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

he built two in one day and now a finish
 

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Here's my XKi speaker. I used PE's sale 6.5" speakers and a small mylar tweeter. I don't have them connected right now, due to the way the room is set up. They're made of formcore, like XRK971 did. They're 12x7.25x8.75". I don't have any test equipment, so don't know how smooth the freq response is, but they sound really good to me.
 

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I was a bit surprised at your suggestion (to remove the grill) as I would have thought that an open grill would have limited impact (though I cannot see with xetail exactly how tight this mesh grill is) on the speakers performance and wonder. I never use them myself so I have little to no experience with them. Could you elaborate on the impact upon the sound a grill like this will make? I am sure there are many who thought just as I did. Thanks very much.
 
Gee jaxboy - those are really nice and a great size (I like the looks of the grill).

My buddy fired up one of the XKi-8 loaded with Eminence Alpha 8 and topped with a piezo for quick evaluation and gave it several good remarks (and none "bad" )

It was tuned with a 6" deep by 10" side x 0..75" port - I'm guessing. roughly 70Hz.

It could stand alone and play quite loudly with the Alpha8.
 

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Nice work. I would remove the perforated grill if possible. Are these the 6.5in polycone $5 drivers? I have used those before and they sound very smooth. They do need a tweeter though.
Yes, they are. I also used them in my Nautiloss speakers. I had already bought the grill (anti-kid poke insurance), but would not put them on were I able to do it again. As you can see by one of the pictures, I did include a tweeter, but my freq range is about the same as those speakers, so I would not include the tweeters if I were to do it over. Again, thank you so much for the designs and for all of your advice. You are my guru for cone-type speakers, and it was you that also got me into DMLs.
 
I used a 12x16" Walmart artist canvas panel. Some people used 16x20" ones, or even larger. I painted it with 4:1 diluted acrylic paint, 1 coat on the back, 2 on the front. I rounded the corners of a 4x6" 3-ply paneling piece that I sanded on both sides until just the center ply was left. I used full-strength pva glue (Titebond) to glue it to the center of the back, and used the glue ring that came with DAEX25FHE4-4 exciters. I attached a 12x1" strip of wood across the frame centered over the exciter, with a thin piece of foam between it and the strip to keep the exciter from vibrating too excessively. You will need to put spacers between the frame and the strip so that it is just above the back of the exciter, allowing enough room to put the foam in between. Some people glue the exciter back directly to the strip. Mine goes down to 40 Hz, but don't play heavy bass or very loud music through them, as they will vibrate too much. I put a 1kmf capacitor in line with it to cut off the music at 60 Hz when playing it loudly. Don't play thumping music through them as they will hit the strap with the vibration. I really enjoy mine. Total cost, including shipping, was less than $40. There is "A study of DMLs as a full-range speaker" forum on diyAudio. Spedge is the guru to look up on it.
 
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Wow - that's lots of detail - Is it also featured at Parts Express? a picture of the rear would help - I like percussion and if can get away with it - at good levels.

On the XKi front I've about got my buddy talked into making one 10" driver box (~18"x13"x13") to compare to XRK 971's 8 inch cabinet. - might not be any real point - ha.
 
Wow - that's lots of detail - Is it also featured at Parts Express? a picture of the rear would help - I like percussion and if can get away with it - at good levels.
You really should use a subwoofer for the pounding deep bass, as a DML will rattle if you hit it with loud heavy bass. I do, and that is the easiest way to get it. Use that 8" or 10" to make one.
 

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sorry to derail the discussion - thanks jaxboy - very helpful pix.

Regarding double XKi where drivers are vertically stacked, is the following
sensible enough without extending the shelf vent forwards to make it closer to the top of the aperture ?
 

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Looking through this thread, XKi needs low Vas and low Qts. Wouldnt Markaudio CHP-90 be also a good candidate? From my noobish view the parameters are pretty similar. Would it be a drop in replacement for 2143 XKi?
FS 48.53 Hz
VAS 20.05 L
RE 6.2000 Ohm
QMS 2.2008
QES 0.4354
QTS 0.3635
BxL 4.8444 Txm
SPL 89.2353
SD 0.0085 m2
CMS 1.9898 mm/N
MMS 5.4051 g
RMS 0.7489 WM
MMD 4.9619 g
L1kHz 0.2642mH
L10kHz 0.0880 mH
PWR 40 watts (Nom)
X MAX (Mech) +/- 7mm
Data from Markaudio website.
 
Founder of XSA-Labs
Joined 2012
Paid Member
461843d1422331652-xki-xs-ab-initio-karlson-6th-order-bandpass-xki-rs100-4-tape-neweq-polar.png


This was made in my usual spot inside my lab on top of a 30in tall stool about 3.5ft away from back wall. Mix was about 36in high off the floor. So there are walls for sure but mix is 0.5m away so helps to reduce ceiling and floor bounce.

It’s been a while but I think the above is with EQ applied. Here is difference between raw (red) with high pass filter (green) and with EQ (blue):
461175d1422071148-xki-xs-ab-initio-karlson-6th-order-bandpass-xki-rs100p-effect-hpf-eq.png


Here is typical photos of the setup (different speaker but similar setup).

IMG_5710.jpeg
 
I guess my "Kube12" qualifies as an "XKi". It and larger are something I visualize as midbass modules in a multi-way K-system. 3fe25-4 in a tiny K is something I wish to get going for little 2-way toys.

Kappa 12a/BC PL21/PRV260 ring radiator. Response usable to 60Hz (sounds greater)
 

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