Mini Karlsonator (0.53X) with Dual TC9FDs

@elleman - - The "Karlsonator" by GregB had its width and cavity form based on Karlson's 1955 or 56 Karlson Twelve aka "K12" - - mine tune ~37Hz. I think X's scalings are based on it. GregB also published Karlsonator6 and Karlsonator8 plans.

Here's the 2nd K12 from ~1956 as published in the July 1958 issue of Popular Mechanics https://i.imgur.com/Mc684UA.jpg

The first K12 ("Karlsonette") was introduced in the fall of 1954

GregB made estimates of the front chamber effect and IIRC used Martin king's Mathcad sheets for overall response estimates. xrk971 developed an Akabak routine for
the Karlsonator.
 
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Thank you for the explanation Freddi,

Let me run a simulation and see what ideal scaling is for W6-658E.
Thanks for offer to make plans.

Did you get any results Xrk?

I will try to get familiar with Akabak, First hurdle will be to get it running... Im more used to mechanical simulation but i hope to find some synergies.

I have been lurking on this site for some time and have come across a few very incredible scripts created by the community, such as the BIB Calculator, Folded horn Spreadsheets etc. Would it be possible to start working on something similar of the Karlssonator? Using selected driver parameters as base for estimating new Scaling etc. I would be happy to help in such a project.
 
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Sorry, have not had a chance lately. Akabak is very powerful, but is legacy software and requires a 16/32bit virtual machine to run Windows in order to function and when my Win 10 machine got an update, it killed my virtual machine. So the Akabak only works on my other machine which is at home.

The Akabak script for the Karlsonator is quite complex if you want to model the effect of the Karlson aperture. The rest of the speaker is similar to a folded band-pass (like a tapped horn) but TQWT mass loaded TL.

I describe how to model the K aperture in this thread:

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

A Speaker that Kicks Butt in Large Spaces

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


This is the K15 (the Karlsonator is different but uses the same model for the aperture above):
354699d1371437170-karlson-k15-akabak-2-png
 
Has anyone made a larger scale Karlson Rocket or upwards facing Klam? Just interested as I made a mini Karlson cabinet and a Rocket like design using some 130mm Visatons and preferred the Rocket Design.



I'm still contemplating a Karlson design for the old Fostex 208 Sigmas, but the more I read I think they might do better in a backloaded horn.
 
These are my first set, with the TC9 in black foamcore. I was going to bring the .53's with the dual 3FE25 but we were trying to get the kids out the door so last minute I ended up leaving them home. As it is these little guys drew a good bit of attention, and would definitely benefit from having a set of 3FE25 swapped in at some point. The flea amplifier and a pair of 3FE25 would be a killer setup for those on a budget and/or wanting a nice small setup for smaller rooms, as the combination punches beyond its weight for sure.

At the raffle I scored a pair of Fountek FE83 8ohm that could prove useful, and some rather heavy 12" 26 pound(!) full rangers that I'll post some info on to see if you can do a sim for me, I may try to do them in a full size Karlsonator!
 
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Hello, I just build a slightly modified Karlsonator to fit Tb W6-658E out of 12mm (shitty) plywood.

An externally hosted image should be here but it was not working when we last tested it.


X-max:4.10 mm
Vas:28.31 Litr
Qts:0.44
Qms:4.49
Qes:0.49
Complete speaker data here: W6-658I - 6.5" PPM. Woofer - TB SPEAKER CO., LTD.

The dimensions i ended up with was something close to this:

704977d1537623537-mini-karlsonator-0-53x-dual-tc9fds-sk-rmklipp-png


704978d1537623537-mini-karlsonator-0-53x-dual-tc9fds-sk-rmklipp2-png


So far it does its job but i expect a more refined version sound better. The final version will probably be 16mm MDF.

The "original" karlsonator dimensions i have found seems to be this:

Karlsonator.png


And the 6" version has more changes than just scaling:

Karlsonator-6.png


Are the W6-658E suited for a Karlsonator at all and what would be the correct way to scale?

In more general terms, what different options would be usable to be able to scale individually? I am thinking of making an parametrisation/automation where it will generate new plans according to new conditions, so any input regarding what dimensions you would like to modify and i will be happy to automate plans for you.

I just ran a sim for the W6-658I and it has a surprising result. The optimal speaker is quite large (1.0x scale tall and deep x 0.5x scale wide - a skinny tall aspect ratio). This gives the flat and deep response.

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A Karsonator with scale of 0.66xHD and 0.72xW - which is approximately what you built has a predicted response like this (very strong 70Hz overshoot and not very deep bass):

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These are my first set, with the TC9 in black foamcore. I was going to bring the .53's with the dual 3FE25 but we were trying to get the kids out the door so last minute I ended up leaving them home. As it is these little guys drew a good bit of attention, and would definitely benefit from having a set of 3FE25 swapped in at some point. The flea amplifier and a pair of 3FE25 would be a killer setup for those on a budget and/or wanting a nice small setup for smaller rooms, as the combination punches beyond its weight for sure.

At the raffle I scored a pair of Fountek FE83 8ohm that could prove useful, and some rather heavy 12" 26 pound(!) full rangers that I'll post some info on to see if you can do a sim for me, I may try to do them in a full size Karlsonator!

Can I ask you if the dual 3FE25 is a worthwhile upgrade to the single version?
I still don't know if I should bother building the dual version or go with
a BLH like the Frugal.

Klaus
 
My single driver karlsonators use the Vifa TC9FD, and the dual driver version using the Faital Pro 3FE25-16 is a very large improvement (not to say the TC9 versions are bad, because they are still great!) due to overall sensitivity, and the bass response is a little better too. You will find the HF response a little better (or maybe just more prominent?) with the 3FE25. I really like both versions, but the 3FE25 dual is a clear winner if I had to choose.


My bottom-line advice-

On a budget, and want to see what all the fuss is about, with an affordable driver and minimum materials? Go for TC9FD. Also good bookshelf or desktop size. For me a pair of drivers cost ~24USD before shipping. Excellent value.

If cost isn't a large factor go for the 3FE25 dual driver from the get-go. A bit larger, but worth it. A pair of drivers for these cost ~80USD before shipping. More costly, but worth it for sure. Build went a little easier too, due to larger size and spacing between parts for gluing it up.


My TC9 versions live in the garage, and the 3FE25 versions live in my main system. Tube amps on both. 1 watt is all it takes to run the dual version as loud as I could ever want them in the house :)
 
I know its a hassle - expense and once built, something rather large to be laying around but having a K15 could be fun - maybe not for the Aucharm-Feastrex.

Here's mic on the ground for K15 with 40 sq.in. vent with the discontinued Beta15cx which had spec of qts = 0.54, fs- 34Hz, vas - 366.4 liter. It wasn't taut sounding on
Mickey Hart's DAFOS "The Beast" until I tightened the lowpass gap (rear shelf) area. Your pretty Feastrex have qts a lot higher plus tube amp will raise effective qts.

https://i.imgur.com/6xSYTCH.jpg

If I had a 12" close to your speaker in qts, fs and vas, then could add a series resistor and see how it measures in the Karlsonator 12
 
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the 3FE25 versions live in my main system. Tube amps on both. 1 watt is all it takes to run the dual version as loud as I could ever want them in the house

Nice to confirm that the predicted sensitivity is very high. I will soon be the recipient of a pair of 0.53x Karlsonator cabinets for dual 3FE25-16's in 1/2in plywood, through the generosity of a member on DIYA. I will see if I can tame the wooden box curse with appropriate dampening materials on the inside and in the front chamber. I even ordered a 1mH aircore and have some resistors handy to make a BSC, if needed.

I am hoping that my 4w SE Class A headphone amp (the Silicon Harmony, designed by Hugh Dean) can power the new high sensitivity speakers well.

Here's mic on the ground for K15 with 40 sq.in. vent with the discontinued Beta15cx
That is a pretty nice measurement, Freddy. How does it sound with music? I suspect pretty good. If you add a CD tweeter and crossover, you will all set.
 
Thanks Lingwendil
I already got two pairs of 3FE25 but unfortunately in the 4 Ohm version.
I may run them in series configuration or with two of the TDA 3116 amps.

I really don't like to halve cut this thin foam stuff to bend it, do you think
one could just cut the board to size and glue them together with some support
sticks like in the attached picture of my cardboard version?
 

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Nice to confirm that the predicted sensitivity is very high. I will soon be the recipient of a pair of 0.53x Karlsonator cabinets for dual 3FE25-16's in 1/2in plywood, through the generosity of a member on DIYA. I will see if I can tame the wooden box curse with appropriate dampening materials on the inside and in the front chamber. I even ordered a 1mH aircore and have some resistors handy to make a BSC, if needed

That's a really cool thing of them to do! I have no doubt that you can make them sound great, maybe line the inside pretty liberally, and play with different suffing inside. I even read an article a while back about running a layer of adhesive on the interior of a box, and covering it with flocking material, supposedly helped to dampen the boxy sound of rather large cabinets with high Qts drivers. I think some good lining along the back of the K-aperture will help a great deal, and likely along the back wall, baffle, and insides of the rear chamber.

I've personally heard a plywood set that sounded fantastic, but i think the entire inside was lined, in addition to the usual stuffing. I really want to do a full sized Karlsonator at some point in plywood, and plan to do the same.


I am hoping that my 4w SE Class A headphone amp (the Silicon Harmony, designed by Hugh Dean) can power the new high sensitivity speakers well.

I think 4W will be plenty, for average use. Maybe not party SPL unless you cross the low end to a sub, but you should be pretty happy :)

Thanks Lingwendil
I already got two pairs of 3FE25 but unfortunately in the 4 Ohm version.
I may run them in series configuration or with two of the TDA 3116 amps.

I really don't like to halve cut this thin foam stuff to bend it, do you think
one could just cut the board to size and glue them together with some support
sticks like in the attached picture of my cardboard version?


I think that would work fine, you may not even need the support sticks. The glue is much stronger than you think. Follow mudjesters plans and just cut instead of score for the baffle bits, and I think you'll do just fine.
 
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I know its a hassle - expense and once built, something rather large to be laying around but having a K15 could be fun - maybe not for the Aucharm-Feastrex.

Here's mic on the ground for K15 with 40 sq.in. vent with the discontinued Beta15cx which had spec of qts = 0.54, fs- 34Hz, vas - 366.4 liter. It wasn't taut sounding on
Mickey Hart's DAFOS "The Beast" until I tightened the lowpass gap (rear shelf) area. Your pretty Feastrex have qts a lot higher plus tube amp will raise effective qts.

https://i.imgur.com/6xSYTCH.jpg

If I had a 12" close to your speaker in qts, fs and vas, then could add a series resistor and see how it measures in the Karlsonator 12

If I hadn't moved into a small apartment I would build such a beast in a heartbeat. My horn system is collecting dust while I'm fiddling with these
tiny drivers. I must admit though, I am having allot of fun. Especially because there is no endless fiddling with crossovers to get it just right.
Those little Faitals just sound really good in my little office.

Klaus
 
I just ran a sim for the W6-658I and it has a surprising result. The optimal speaker is quite large (1.0x scale tall and deep x 0.5x scale wide - a skinny tall aspect ratio). This gives the flat and deep response.

708069d1538942538-mini-karlsonator-0-53x-dual-tc9fds-karlsonator-w6-658i-1-oxhdx0-50xw-freq-png


A Karsonator with scale of 0.66xHD and 0.72xW - which is approximately what you built has a predicted response like this (very strong 70Hz overshoot and not very deep bass):

Thank you very much XRK!
That will indeed be a funny looking karlssonator.

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The woofer choice is only because i have a i few of them laying around.. (Intended for a cheap pick-nick boombox).

Since the woofer is not full-range, i need to add a tweeter. I have 4 Woofers available which means i could do something like this. Then i also have space for amp and crossover behind the tweeter.

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I currently have this Random Tweeter. Would it make any sense to make a horn for that one?
 

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