Mini Karlsonator (0.53X) with Dual TC9FDs

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Edit Nov 30, 2021: Andrewbee posted plans (that he got somewhere on DIYA, we thank the author whoever you are) for a Karlsonator for the W5-2143. I don’t remember the simulation on this one but I have literally done hundreds so would not surprise me if I forgot. Looks like a taller aspect ratio and that makes sense as this driver has a lower Qts and more powerful motor.
https://www.diyaudio.com/forums/attachment.php?attachmentid=1001541&d=1638274724

Edit Jan 16, 2021: A beautiful example of dual 3FE25-16 Karlsonator by Ripson. He went all out and covered them with repurposed antique pine from a barn and made grill too:
grille.jpg


Edit July 3, 2020: Gecko made a beautiful foamcore 0.53x with PA130-8 and cherry aperture:
ACtC-3f6ji8A5bz2bwQ3vzBA393tRTcgoEh127UDNGDUXxRuCxKEuSOe4z4RlnknWiXWUPFUZAwIMoTdKLX_JF4DIuxHazWWRW4taMOl7-QLGHzb5cwX99X7PJkotFwZm_6--9iDGjRreb5M4OHIhNjhkv34kw=w952-h1171-no


Edit Feb 10, 2020: super 0.4x* build by vox with 3FE22:
815877d1581326429-mini-karlsonator-0-53x-dual-tc9fds-07614d6c-9f99-4751-8276-03a0ec318f40-jpeg

*scale slightly smaller than 0.4x

Edit Feb 6, 2020: just managed to locate nice plans by Skylar88 for dual 3FE25’s:
634541d1504988311-aca-speaker-short-list-capture-jpg


Edit Dec 16, 2019: tips on adding sound dampening foam for wooden mini Karlsonators here
Mini Karlsonator (0.53X) with Dual TC9FD's

Edit June 23, 2019: 0.53x Karlsonator plans in BB plywood by Jhofland here:
Mini Karlsonator (0.53X) with Dual TC9FD's

Edit: Feb25, 2018 - New "Score and Fold" CAD plans of 0.53x Karlsonator by Mudjester in metric and English units! A huge thank you to Mudjester for making this very comprehensive planset - one of the best I have seen ever!. These plans are in 1:4 scale in case you want to print out and use a ruler to measure and scale. Thread discussion here.
Metric:
http://www.diyaudio.com/forums/atta...fds-0-53x-karlsonator-score-fold-plans-mm-pdf

Engish:
http://www.diyaudio.com/forums/atta...tc9fds-0-53x-karlsonator-score-fold-plans-pdf


Edit (Apr 29, 2015): Latest 0.40x K'nator Score-N-Fold Plans by Mudjester available here: https://www.diyaudio.com/community/attachments/0-4x_karlsonator_plans-pdf.1027626/

EDIT (Mar 29, 2015): The Dayton PA130-8 driver ($18) works exceptionally well in a 0.53x scale Karlsonator. Very rich full bass and great sensitivity too.
Mini Karlsonator (0.53X) with Dual TC9FD's - Page 133 - diyAudio

0.53x with PA130-8:
474550d1427659994-mini-karlsonator-0-53x-dual-tc9fds-0.53x-knator-pa130-8-photo-k.png


Here is the measured response of the PA130-8 in the 0.53x (at 0.5m with speaker in 29in high stand) - the red trace. Note that scale is 5dB/division and this is gated to 4ms and 1/48th octave averaging. The performance of about +/- 3.5dB is very good for a K aperture and good for many speakers in general:
474642d1427700312-mini-karlsonator-0-53x-dual-tc9fds-0.53x-knator-pa130-8-phase-0.5m.png


In stereo as a stand-mount speaker the imaging is fantastic and with a wide sweet spot afforded by K aperture:

474781d1427744846-mini-karlsonator-0-53x-dual-tc9fds-foam-core-lab-knator-stereo.jpg



EDIT (12/1/2013): There is a 0.4X single driver version that is only 12 in tall x 6 in wide that works very well. Go to post 160 for details
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-16.html#post3722988

EDIT (1/3/2023): Here is the DXF file for laser cutting a score and fold 0.40X foamcore Karlsonator, file provided generously by member @mudjester.
https://www.diyaudio.com/community/...or-0-53x-with-dual-tc9fds.239338/post-7554841

Here is a photo of the 0.4x

385169d1385877585-mini-karlsonator-0-53x-dual-tc9fds-photo-build-03.png


Here is the predicted response of the 0.4x with a single TC9FD with 2 watts power and listening near field at 24 in (on a desk for example) and a wall located 5 ft away.
385369d1385996783-mini-karlsonator-0-53x-dual-tc9fds-karlsonator-0.4x-tc9fd-freq-24in-reflections.png


Edit: Hot off the press! Sept 17, 2014 - Here is the measured response of the 0.40x with a Faital Pro 3FE25 driver (4ohm):

439061d1411026705-mini-karlsonator-0-53x-dual-tc9fds-karlsonatpr-0.40x-3fe25-avg.png


Here is the sound clip with the 3FE25:
diyAudio

Here is a nice drawing of the 0.4x plans by Bl21de3 (Blaides):
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-56.html#post3880182

Here is the Cut and Fold Razorlab or Ponoko File version of the 0.4x for a smaller Visaton FRS8.
http://www.diyaudio.com/forums/full...onator-0-53x-dual-tc9fds-103.html#post4113372

410245d1396600506-mini-karlsonator-0-53x-dual-tc9fds-karlsonator_04x_print.png


Edit: Sept 18, 2015 - Plans for 0.44x tall x 0.44x deep x 0.55x wide K'nator for FE103SOL or FE103/RS 40-1197: https://plus.google.com/photos/1005...6195254979670171890&oid=100545049816297868412

Here is the post showing details of the build process for a Score & Fold 0.4x:
http://www.diyaudio.com/forums/full...onator-0-53x-dual-tc9fds-115.html#post4139973

Post 198 has a nice CAD drawing of the dual driver 0.53x plans by Tb46.
diyAudio

Edit Mar 8, 2017: Here is a nice plan for a 0.50x & 0.42x wide Karlsonator for a Pluvia 7

http://www.diyaudio.com/forums/atta...or-0-53x-dual-tc9fds-karlsonator-pluvia-7.pdf

http://www.diyaudio.com/forums/atta...onator-pluvia-7-cutting-folding-glue-plan.pdf
----

I started this idea in the Speaker that Kicks Butt thread here:http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-19.html#post3553874 , and found that the speaker I built worked so well, and there has been interest shown by others for plans and construction details that I thought it deserves it own thread. I have to give credit to GregB who designed the Karlsonator (full scale) as this speaker was simply scaled down in size by approximately 0.53X to accomodate the dual drivers on a vertical orientation. The Karlsonator original plan can be found here:
https://lh3.googleusercontent.com/-...ABik/txissf4J4PI/w678-h524-no/Karlsonator.png

This speaker could be built out of plywood certainly, but as a foam core build, it was very easy to make (about 2 hrs) and is a very cost effective great sounding speaker. If you are familiar with my work, you will notice the recurring commonality: the Vifa TC9FD driver. This is a great sounding inexpensive little driver and I was surprised that it works in this type of enclosure given that it is relatively high Qts. I would not have built it had I not simulated it in AkAbak first (http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-19.html#post3553874)

The initial sim shows a nice punchy bass shelf down to about 70 Hz:
358812d1373293761-speaker-kicks-butt-large-spaces-karlsonator-8x-dual-tc9fd-freq-3m.png


I then proceeded to build it in an evening, and it was quite a fun and easy build that can be done with exactly 2 sheets of $1 foam core board from the dollar store.
359932d1373734918t-speaker-kicks-butt-large-spaces-karlsonator-1s.jpg

Here is the finished speaker:
359935d1373734918t-speaker-kicks-butt-large-spaces-karlsonator-6s.jpg


The plan, optimized for standard 20 in x 30 in x 3/16 in thick foam core material looks like this:
360409d1373945528-foam-core-board-speaker-enclosures-karslonator-0.53x-plan-1.png

360410d1373945528-foam-core-board-speaker-enclosures-karslonator-0.53x-plan-2.png


359934d1373734918-speaker-kicks-butt-large-spaces-karlsonator-5s.jpg


And when I plugged it in and turned it on, WOW! Even in pseudo mono (left channel to top driver and right channel to bottom driver) I was just amazed at the clarity, depth, and naturalness of the sound. The bass was tight and punchy, and easy - not strained. The sounds from vocals was just wonderful, and bass guitar and bowed double bass just had a very natural presentation. The other thing I noticed was that the speakers were very efficient (that is quite loud) with very little cone movement compared to some of the other cabinets that these Vifas had been in before. I immediately just loved the rich natural sound. It works very well with classic rock like Dire Straits as well as female vocals, and jazz. So you may wonder how it really sounds, well I recorded some sound clips and zipped them so they can be uploaded here. Check them out and see for yourself, they are recorded with a Zoom H4 with XY mic at 3 meters away and stored on pretty lossy 128 kbit format so that I could fit them into the max file size limit. The full size files sound even more amazing.

I highly recommend this build, as it sounds great, is inexpensive, easy to build, and gives you the unique opportunity to experience what a Karlson type speaker is all about. I would not have gone about doing this had it not been for my extensive modeling and simulation of a Karlson, which led me to see (on paper) the unique capabilities: wide spatial dispersion, high efficiency, natural lifelike sound, punchy bass.

I will continue this thread with a build log of the second speaker box so that I will finally have a stereo pair and I will document the build process for you to follow.

I hope you give it a try - you will be pleasantly surprised, and you will have a unique speaker that can be used for a variety of purposes. It excels as a table radio in pseudo stereo for great background music that fills the room with a rich full lifelike sound.

Below are the sound clips. Enjoy! :)

Regards,
X


Edit (7/24/2017) - I forgot to include this link for a nice min Karlsonator with CHN-70:
Improving the CHN-70

509046d1444878618-improving-chn-70-chn70-knator-photo-1.png



Edit (Sept 13, 2017): Bonjonno reports that the 0.40x Mini Karlsonator kicks butt as a studio monitor. See post #2120.

635194d1505316980-mini-karlsonator-0-53x-dual-tc9fds-sanc-mk-0-4-jpg


Edit (Aug 23, 2018): Skylar made some nice 0.53x dual 3FE25-8 plans here:
http://www.diyaudio.com/forums/full...onator-0-53x-dual-tc9fds-286.html#post5523965

Edit (Dec. 12, 2018): I have figured out how to make the Karlsonators out of wood without sounding boxy. Here is a great example built by Jhofland for me and I finished with boiled linseed oil and hand rubbed wax. Internally lined with melamine foam pads adjacent to driver in rear chamber seems to do the trick. Also added some pads on sidewalls on front chamber and lined backside of aperture with paper faced foamcore. This particular example is fitted with dial 3FE25-16’s.

912196d1610809539-mini-karlsonator-0-53x-dual-tc9fds-5bd64ac4-d2b7-4f39-af60-eea30c1525e2-jpeg


Sketchup plans for above wooden 0.53x by Jhofland here:
Mini Karlsonator (0.53X) with Dual TC9FD's

Tips on how to apply melamine foam pads to break the "wooden box curse" here:
Mini Karlsonator (0.53X) with Dual TC9FD's
 

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Last edited:
Founder of XSA-Labs
Joined 2012
Paid Member
Bob,
Hey glad you are on board! :) I will run a sim of the Aurasound - you will probably only need one, unless you want a larger box for two. This cabinet is very forgiving with a variety of drivers. One thing with the NS525's is that they don't have much of a top end, and you need that to balance out how powerful the bass is on these guys. Although you can do what you did with the DNA Decware horn and add the tweeter on top. That will let you experiment with a K-tube attached to your tweeter, which I have heard sounds really good. Can you send me a couple of those Vifa's while you are at it? :D
 
As reported, I agree the NS525 is an exceptional value but needs help on top. I would lean toward just one of those because I suspect two would require the 1/2" foam to avoid excessive bracing. That's not really a bad thing, but being able to get really good base using the standard thin foam core is what makes all these projects so special.

Watch your mailbox for the free Vifas, and if they don't show - just keep watching.:whazzat: :D
 
Last edited:
Next FC challenge: a 3x3 array of TC9F in a 12:10 Karlsonator scale-down! :D (works out to a ~10" if adding Sd)

Doing a serious build and trying to get a fair balance of bass extension versus cabinet bulk, I'd probably go with GregB's suggestion on the Fullrangedriver.com forum and use a Fostex FF165WK. It would need some help on top though.

IG
 
Founder of XSA-Labs
Joined 2012
Paid Member
0.6X Karlsonator with Single NS525

It looks like it can work if you scale cabinet up to 0.6X (9/15). There are some big dips though as you get farther away from the speaker. Up to you...
First plot is 1 m, second is 3 m, third is impedance (a little high - may be a problem for amp), last is cone displacement - seems well controlled.
Go for it! :)
 

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Did you post a sim of the full-size K'ator yet, I'm looking but can't find, am interested in impedance mostly. The 0.6 scale-down above would ~ work from my TL length guesstimation. As said in other thread, choking the TL a bit more could bring this tuning down if required.

IG
 
Founder of XSA-Labs
Joined 2012
Paid Member
Did you post a sim of the full-size K'ator yet, I'm looking but can't find, am interested in impedance mostly. The 0.6 scale-down above would ~ work from my TL length guesstimation. As said in other thread, choking the TL a bit more could bring this tuning down if required.

IG

Which driver were you looking to run in a full size K'nator? The FE166EN? I have done that (in a scaled down one), a Kappa 12A, and an FF225WK. I can do any driver - just let me know. I finally spent some time consolidating my AkAbak driver database so that I can quickly copy and paste any one of 55 drivers that I have sim'd so far.
 
Which driver were you looking to run in a full size K'nator? The FE166EN? I have done that (in a scaled down one), a Kappa 12A, and an FF225WK. I can do any driver - just let me know. I finally spent some time consolidating my AkAbak driver database so that I can quickly copy and paste any one of 55 drivers that I have sim'd so far.

FF225WK could be fun for me to see in a full-size K'ator, but a 12" with strong motor could be better and in line with what freddi's interested in. I mainly want to see where the impedance valleys land, which should be invariable with choice of driver.

IG
 
Founder of XSA-Labs
Joined 2012
Paid Member
Bob,
If you want some deep bass and want to go with the NS525, scale the top channel by 0.25X (sounds very small) but still manages to produce 90 dB at 40 Hz. And to top it off, the flat bass shelf goes all the way 250 Hz. That is pretty wide bandwidth for any speaker. To hear the low string on a 4 string bass will be pretty cool, all the way to 250 Hz.

Here is the sim.
 

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Hi xrk971,

I have a few drivers on the shelf that might be of interest in a Karlsonator: the Fostex FE206e (8" NOS) and Aurasound NS525-255-8A (5.25" @ Madisound for @3.60 ea.). Would those show any promise in a simulation? Also, could you share the section of your AkAbak script that describes the front chamber/coupling slot? I cannot figure out how to enter that into AkAbak.

Regards,
 
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Joined 2012
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TB46,
The NS525 is posted above. The sims for the FE206E are below. First plot is full size Karlsonator with 1.0X scale on top channel. Next plot is with 0.35X choke factor to bring tuning down - it reaches the 30 Hz range. Fourth plot is impedance and last is displacement of the cone. It looks like it can work but may sound bright or 'shouty' as some people call it.
 

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Founder of XSA-Labs
Joined 2012
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TB46,
I can help you with how the script goes, I just didn't have time. It is described in earlier posts on the Karlson thread here (http://www.diyaudio.com/forums/full-range/213594-karlson-10.html#post3528706). Basically, I fitted the Karlson aperture curve to a non dimensional function as y= f(x) for x[0,1], and y[0,1]. The function 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).
Using that function, I can then apply scaling of any arbitrary K slot final width and length, and also an offset which determines initial gap width. Having this function, use to specify the width and height of a series of rectangular ports (vents) located along the front. The width will be given by f(x)*Y_scale, the width height will equal front panel height/number_vents. I used 9 vents for the front K-aperture. I tried 14 and found negligible difference. So step through the 9 vents and adjust the port width for each successive one according to the equation. You need to model the front chamber as a series of waveguides (following the cross sectional area profile of the front chamber). I chose 9 because that is how many segments were required to model the front chamber to include all the expansions, contractions, vent tubes, etc. The distance of each segment actually determines the height of the vent. At the node connecting each waveguide segment on the front chamber, connect that node to a duct leading to a front radiator associated with that duct. See diagram here
354699d1371437170-karlson-k15-akabak-2.png

354698d1371437170-karlson-k15-akabak-1.png

The tricky part is to code each duct radiator so that it is appropriately physically located in the correct place on the front panel relative to the driver position. Also, you need to specify the extent of the baffle width and height at the position of the duct vent radiator. All this is rather tedious coding and much of it is manually done. I figured out how to link it all together to the non-dimensional X and Y positions of the individual Karlson ducts.
I hope that helps. Think about it some and let me know if you have questions.
Regards,
X
 
Founder of XSA-Labs
Joined 2012
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Steve,
The FRS8 can work very well doubled-up in a 0.47X scale Karlsonator with the vent scaled further by 0.7X. Pretty good bass extension and good impedance curve. First is 0.53X scale, second is 0.47 scale, third is impedance, fourth is cone displacement.
Looks like fun.
:)
 

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