Mini Karlsonator (0.53X) with Dual TC9FDs

[Mr Baldingfast]

Yes, they sound great. Going to build them up in Baltic birch ply.

 

[Simonism]

Mini Karlsonator (0.53X) with TC9FD and 3FE22

With much gratitude to xrk971 for the design and thread, and to Skylar88 for 12mm plywood plans, I'm now able to show you my 0.53x Karlsonators, each with one 8 ohm TC9FD and one 8 ohm 3FE22 in parallel, giving 4 ohms ... in beta format.

I built them using those particular drivers - because I had them! But I think they work well together - the TC9 is below the 3FE22. I used melamine pads in the box exactly as per X's recommendation, and silver foil/bitumen on the back of the front K-aperture - again because I had it, and didn't have foam core.

I will now finalise the construction and give the boxes some kind of finish.

Please ignore the sound quality in my recording - they sound good!

have fun!
Simon

 

[xrk971]

Nice work, Simon!

The use of different drivers is a great idea. Erik777 did that once in a Karlsonator as I recall. Putting the one with more treble on the lower position might allow you to adjust the balance if you like more treble.

Thanks for the video. More people should post videos of their speakers.

 

[Karlsonate]

G'day to all the lovely folks of Diyaudio
I'm looking forward to building my first pair of Mini Karlsonators (and actually, DIY anything) for desktop listening, mostly music of a wide variety, sorta 80-90s stuffs, with the occasional TV shows and films (no further than 3-4 feet away from the speakers), so perhaps the 0.4x version. Unfortunately, there's only a number of reputable, public TS parameter-available drivers around where I live (the rest are just dubious Chinese imports whose specs are practically shots in the dark). Perhaps XRK or someone here in their spare time could lend me a hand in choosing the best driver for the job (even simulations)? Or am I going to need larger sizes (>4 inch, 0.53x scale)? Here they are:

Drivers	Visaton F8 SC	Visaton SL 713 (*)	Tectonic TEBM65C20F-8 (**)
Sd	30cm2	50cm2	37.2cm2
Fs	125hz	180Hz	104Hz
Mms	2g	1.7g	5.6g
Qms	2.94	8.2	6.65
Qes	1.29	2.2	1.11
Qts	0.9	1.7	0.95
Re	7.9 Ohms	3.6 Ohms	7.1 Ohms
Le	0.3mH	0.2mH	0.05mH
Vas	1L	1.5L	1.1L

(*) It's probably the most unsuitable of the bunch.
(**) Uses BMR technology, I've seen a request for it before but no replies sadly. Also it's apparently regarded as being "bass-heavy for the size".

Many thanks,
K.

 

[xrk971]

The 3FE25-8 works well I know. It has TS params close to Visaton F8. The cabinet is fairly tolerant to variations.

https://www.parts-express.com/pedocs/specs/294-1104-faitalpro-3fe25-8-specifications.pdf

Ultimately, the frequency response in the cabinet will depend on driver and cabinet. We can’t simulate that too well here. Just try it and see. It’s diy.

 

[xrk971]

Plans for 0.4x Karlsonator by Mudjester here:
https://www.diyaudio.com/community/attachments/0-4x_karlsonator_plans-pdf.1027626/

 

[sumeshak]

For the Karlsson aperture, should we have a sharp ending or a slotted ending?
Which one will have a good bass performance?
Regards,
Sumesh

 

[moray james]

depends upon the band you want the taper to start radiating at, small gap radiates high frequency large gap radiates lower frequency. So on a woofer you would not require high frequency so start with a larger gap. I go by ear and do a simple cut and try system it does not take long to decide what sounds best. Sorry but I don't have a technical method for you to follow.

 

[sumeshak]

Thank you!
My plan is to use a single TC9 driver in 0.4x Karlsonator.
Thanks and regards,
Sumesh

 

[xrk971]

TC9 and 0.4x is an excellent speaker. You will enjoy it. Easy to build and high bang:buck payoff ratio.

 

[sdsddsd1]

I am thinking about building a Mini Karlsonator. Its purpose would be to listen mainly to Hardtek and Jungle music. So a good punch in the lower notes is what I am looking for. This would probably 0.53 Karlsonator, or even the Xki?
What drivers would you suggest, the Vifa TC9 oder Faital ones?
I was not yet able to find general starting points for BSC network for each Mini Karlsonator setup.

 

[Skylar88]

Instead of BSC, I would look at the EQ for Full Range Drivers. It's now available in the diyAudioStore. I didn't have much success with baffle steps on my 0.53x with Faital drivers.

 

[xrk971]

Hi Skylar,
I have had good luck with 1mH and 4.7ohm to 6.8ohm in parallel for a 8ohm speaker BSC. Use 0.5mH for 4ohm speaker. Adjust the resistor to taste. Even iron core works pretty well.

 

[Skylar88]

Hi X, I have tried various combinations of inductors and resistors and never liked the sound with the BSC. After a while I resorted to using software EQ and that solved the problem. But I'm quite eager to try the FR EQ of NP in a day or so when the last components arrive, although it will mainly be used for my big 12" bass reflex FR speakers. Now I'm using the 0.53X in my home office in near field and I'm pretty sure that the Faital drivers "matured" as they are not as harsh as when they were new, almost six years ago. Still love them and listen to them every day.

 

[xrk971]

I still use my 0.53x with dual 3FE25-16’s everyday as my main kitchen speakers. After 4 or 5 years now they still sound great and do so many things well.

 

[Rxdroid]

Hello everyone, I have finally decided to manufacture a 0.53x with the Faital 3FE25-16, I see that the frame is stamped creating a significant thickness on the front, the question is, is it convenient to lower the board to accommodate the profile? or that will not affect the diffractions of the speaker by having that foam ring that sticks out more. Thanks for reading.

All the best

 

[xrk971]

You can rebate the front bezel. It will look nicer and may allow easier fit for the basket. It won’t affect diffraction.

 

[henrylarsen]

Hi XRK and others. Is there a file for laser cutting the 0.40 Karlsonator that can be shared? I have handmade Bothe the 0.40 and the .53, but I believe that the finish can improve and I have access to a lasercutter.

 

[xrk971]

Here is the 0.40X DXF file that @mudjester created. It has 3 sheets and was designed for the paper faced foamcore (3/16in thick) with some edges using the score and fold technique. To use with wood you may need to modify to account for thickness changes etc.

 

[henrylarsen]

Thank you very much xrk. Very much appreciated.