Mini Karlsonator (0.53X) with Dual TC9FDs

Dual TC9FD vs PA130-8?

A few questions for the experts.

In 2014 I made some small Karlsonators and bass reflex speakers in foam board with small Fostex speakers driven by a small DIY amp board. Loved them.

I am now looking to do a 3116 amp and some speakers for music (classical, instrumentals and jazz) and TV binge watching (do not need big booming bass for explosions etc.). 12 by 24 living room. I have been reading back thru the threads to prepare. Looking at either a dual TC9FD18-8 or a single PA130-8. But open to other driver suggestions (speaker budget of $200, less is better).

I want to use wood this time, rather than foam board (full wood workshop available).

Questions. Are both options to use the 0.53 Mini Karlsonator? If not, which scales are they to be used in? Will wood require different dampening? Suggestions?

Love the sharing of info and knowledge seen on this thread.
 
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Jack Skip,
The 0.53x works well with dual 3F25-16’s. I would not make them out of all wood. People who have done this say it doesn’t sound as good as foam core. If you must, add thin 3/16in layer of wood over the foam core aperture and foam core driver baffle mounting board. You can be off on the dimensions a little and it’s not a big deal. So you have dual TC9FD (or it’s cousins TG9FD, 3PYMxxx. Also the PA130-8, and now, dual 3FE25.

You can also veneer the foam core. It has something to do with the absorbent nature of the foam.
 
You can also veneer the foam core. It has something to do with the absorbent nature of the foam.

Incidentally, I was considering cladding my foam speaker boxes with the 4mm LitePly that I bought for rebuilding them. I really loathe breaking up such good speakers just to rebuild them from LitePly. Having wood on the exterior will be more durable as well as having a higher WAF.

I think the trick will be to glue the LitePly down all over to avoid rattling panels. Not sure what adhesive to use, since some gap filling is required where the foam board warped and buckled slightly. Gorilla Glue might work, since it's gap filling, but I believe it can expand quite a lot. Have never used the stuff, so will have to experiment.

.
 
Mini Karlsonator 0.4x

Hello X,

My progress so far on 0.4x mini Karlsonator. Still some way to go before I finish one speaker. I used something called sunboard for my build which is pretty strong but can be cut and worked with. It took full day's work to get here.

Can you please let me know if I can use Visaton B80 in these? I have kevlar version of TC9 which I can use as well if B80 is not a good fit.

Thanks
 

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Hello X,

My progress so far on 0.4x mini Karlsonator. Still some way to go before I finish one speaker. I used something called sunboard for my build which is pretty strong but can be cut and worked with. It took full day's work to get here.

Can you please let me know if I can use Visaton B80 in these? I have kevlar version of TC9 which I can use as well if B80 is not a good fit.

Thanks

That looks really good. I think the B80 should work fine - that's about the highest end driver I think anyone as tried in a 0.40x Karlsonator. I haven't done a sim yet but it is close enough to the other 3.5in drivers that do work (TC9FD et al).
 
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Incidentally, I was considering cladding my foam speaker boxes with the 4mm LitePly that I bought for rebuilding them. I really loathe breaking up such good speakers just to rebuild them from LitePly. Having wood on the exterior will be more durable as well as having a higher WAF.

I think the trick will be to glue the LitePly down all over to avoid rattling panels. Not sure what adhesive to use, since some gap filling is required where the foam board warped and buckled slightly. Gorilla Glue might work, since it's gap filling, but I believe it can expand quite a lot. Have never used the stuff, so will have to experiment.

.

I have used construction adhesive that comes in a caulk gun tube. In the US it is called Liquid Nails (non volatile version). I think Loctite PL Premium woul work too. Make sure it is not the volatile verssion as the vapors melt the foam core.

Latex caulking works as well but can be a bit too wet moisture wise. You want something pliable to absorb rattles etc.
 
Completed mini-k 0.4x

Hello X,

I got one mini-k completed. It sounds fine and I can hear some bass but not sure how low it is going.

I need to spend time with it to understand it better. As of now, I am listening it with other speaker being Tabaq and after listening to this speaker, I realize there is some leakage in my tabaq since there is less bass in that.

Anyway, it is good speaker and pretty compact. Lets see how it goes.

Thanks for providing the design like so many others you have done.

Thanks
Balaji
 

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Those look great.


For anybody who cares, my 6SN7 Flea amplifier and single TC9FD Karlsonators will be at Burning Amp fest this month, so if you wanted to check them out, swing on by.


My dual 3FE25-16 .53x K's are still my main system, btw. I run them off of a nice 6CW5/EL86 amplifier. Great all-around speakers :)
 
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For anybody who cares, my 6SN7 Flea amplifier and single TC9FD Karlsonators will be at Burning Amp fest this month, so if you wanted to check them out, swing on by.

Very cool! I hope many more people get to experience this. So even with a TC9FD, you feel that a fleawatt is sufficient to power it - as you must like it a lot to bring to BA to show it off :) It's a great little speaker.
 
One watt is plenty for bedroom or workbench SPL for sure. The .53x with the dual 3FE25 is an even better fit, but the .41x with the single TC9s are still very nice. I usually have the TC9/flea rig going in the garage when doing car stuff, and it's plenty. The amplifier itself could use a tad more gain when used with a cellphone as a source, but that's minor nitpicking really :)
 
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Hello X

Please. I'm still in doubt regarding 10.2/10.3 excursion at 60hz and below. Is that harmful to the drive?
Thanks for help again.

Yes, sorry I missed this. Regarding excursion at low bass frequencies: many drivers will show this behavior when subjected to deep bass (< 60Hz) as experienced on home theater style tracks. Usually it is not a problem as this kind of content is rare and is only for occasional bursts. You need to check what x-damage is and keep your amp drive below that level. xmax is more for where distortion is audible. xdamage is usually 2x xmax (if not more in many cases).

Specs for 10.2 state xmax is 8.5mm (one way):
https://www.markaudio.com/Archive/item/download/97_9f00ab82530203df13abf6fa3cfabbfe

The sim shows displacement of 2.8mm for 2.83v so you should be good for about 8vrms (or 8w) before xmax is a problem. But do check with manufacturer what xdamage is.
 
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Finally making a little more progress. I got sidetracked with restoring my friend’s Sansui AU-717. Finished felt and foam in one speaker last night and glued the side panel on. All that’s left is a few solder connections on the drivers, a few screws, and the K-apetures.

Let me know if you see any issues with any of my work. I’ve left a lot of the foam and stuffing loose for adjustment later if needed.
 

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