Some notes
Gkh ,
Don't forget to brace the bottom panel...
Also ,the lining must be kept at least 2.5 inches away from the internal end of the duct .... Take a look at the notes i added to your sketch (below) so you can see what i mean 🙂
Being raised a few inches off of the ground should be fine , but if it is on wheels it might try to scoot itself around when the sub is playing at high levels 😛 ... Could be ok on carpet i suppose .... (if you do decide to go with wheels be sure to use some that won't rattle when vibrated)
Having MMJ's approval and a few cups of coffee later, added bracing, stuffing etc:
Gkh ,
Don't forget to brace the bottom panel...
Also ,the lining must be kept at least 2.5 inches away from the internal end of the duct .... Take a look at the notes i added to your sketch (below) so you can see what i mean 🙂
An externally hosted image should be here but it was not working when we last tested it.
I really hope that putting the box on 2" wheels wouldn't affect it's FR too much? 😕
Being raised a few inches off of the ground should be fine , but if it is on wheels it might try to scoot itself around when the sub is playing at high levels 😛 ... Could be ok on carpet i suppose .... (if you do decide to go with wheels be sure to use some that won't rattle when vibrated)
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Hi gkh, the mounting hole is 7 x 9 mm. Looking forward to hear how The Box is doing in the next Karlflex build 🙂
View attachment 628805
Hi, Schlager!
The diameter I need is the "big hole" through which the driver is mounted, not the oter diamerter... 🙂 Thanks anyway 😀
It is a few things rolled into one =)
USRFobiwan,
The Karflex is a Series-Tuned 6th order cabinet .... .. ..... A sort of Karlson coupler inspired OD-ML-QWP(TL)+ Transflex hybrid ..... What Freddi would call a K-Variant ....
It has a rear chamber and a front chamber connected in series by a duct ... There are also two tuned stubs which help to tame the pipe harmonics and flatten the response. 🙂
We painstakingly designed it using Akabak software and then refined it a little further after building the prototype ..
Take a look at the Sketch and details at this link ..
Mattcalf in Australia just built a Karlflex-15 .... Build photos are here and the final product can be seen here .... Not a bad looking cabinet , Mattcalf did a good job 🙂..
The Karlflex was designed to be compact so it doesn't have the extreme efficiency that a huge SUPER PLANAR cabinet or massive horn might have but for it's size the Karlflex can suffice for many situations when loaded with the right drivers (which is key)...
Does this design have 3 different tunings, or do I look at it the wrong way?
USRFobiwan,
The Karflex is a Series-Tuned 6th order cabinet .... .. ..... A sort of Karlson coupler inspired OD-ML-QWP(TL)+ Transflex hybrid ..... What Freddi would call a K-Variant ....
It has a rear chamber and a front chamber connected in series by a duct ... There are also two tuned stubs which help to tame the pipe harmonics and flatten the response. 🙂
We painstakingly designed it using Akabak software and then refined it a little further after building the prototype ..
Take a look at the Sketch and details at this link ..
Mattcalf in Australia just built a Karlflex-15 .... Build photos are here and the final product can be seen here .... Not a bad looking cabinet , Mattcalf did a good job 🙂..
The Karlflex was designed to be compact so it doesn't have the extreme efficiency that a huge SUPER PLANAR cabinet or massive horn might have but for it's size the Karlflex can suffice for many situations when loaded with the right drivers (which is key)...
MMJ,
thanks for your comment - will correct the drawing asap 🙂
My floor is parquet, but these wheels ought to do fine (used them and their larger siblings for years in pro audio).
BTW, the SuperPlanar project hasn't died at all, it's just delayed a bit. Having proper audio in my living room / office again is vital 😀
thanks for your comment - will correct the drawing asap 🙂
My floor is parquet, but these wheels ought to do fine (used them and their larger siblings for years in pro audio).
BTW, the SuperPlanar project hasn't died at all, it's just delayed a bit. Having proper audio in my living room / office again is vital 😀
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Ok, that's why I attached the specs in post 2038 😉 from that you can see that mounting hole is 372 mm, enjoy.
Ok, that's why I attached the specs in post 2038 😉 from that you can see that mounting hole is 372 mm, enjoy.
Schlager,
please blame it on my bad english - what I meant is the CUTOUT diameter

Many thanks!
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You can , no problem
Gkh,
If you wanted to round up the internal width to 490mm, that is totally fine, it won't hurt anything at all 🙂
Keep in mind that the bracing in the tuned stubs (located towards the back of the box in the vertical stub, and also at the top of the cab in the horizontally oriented stub) should be solid panel bracing , no holes .... The bracing in these sections are performing double-duty because they act as both solid dividers as well as braces 😀 (highlighted in green in the most current Karlflex plans/sketch) ................................... ..................................We did this because in the wider versions of the cabinet (100L and 120L) the tuned stub sections ended up being nearly square in their dimensions so we needed something to divide that space to help prevent any unwanted resonances from developing there .... Just a precaution really ... ................................... It is something we thought of when Sebastian Schlager built a variation of this cabinet that used a much larger and much more complicated front chamber.... His complex version definitely produced some strange resonances and colourations that we could not damp out as much as we tried ......................... The good news is that nobody has reported any such weirdness with this current version of the Karlflex cabinet......This up-to-date model uses a simple front chamber with the single stuffed Freddi-Mod tuned stub,. while the rear chamber also only has a single stuffed and tuned stub....This combination seems to do well, but i suggest employing the solid divider style braces anyhow just to keep any potential for undesirable resonant weirdness at an absolute minimum .. 🙂
Drawing corrected, bottom brace added...
View attachment 628892
I wonder with so much bracing, if the internal width shouldn't be a bit larger, let's say 490mm instead of 484mm?
Gkh,
If you wanted to round up the internal width to 490mm, that is totally fine, it won't hurt anything at all 🙂
Keep in mind that the bracing in the tuned stubs (located towards the back of the box in the vertical stub, and also at the top of the cab in the horizontally oriented stub) should be solid panel bracing , no holes .... The bracing in these sections are performing double-duty because they act as both solid dividers as well as braces 😀 (highlighted in green in the most current Karlflex plans/sketch) ................................... ..................................We did this because in the wider versions of the cabinet (100L and 120L) the tuned stub sections ended up being nearly square in their dimensions so we needed something to divide that space to help prevent any unwanted resonances from developing there .... Just a precaution really ... ................................... It is something we thought of when Sebastian Schlager built a variation of this cabinet that used a much larger and much more complicated front chamber.... His complex version definitely produced some strange resonances and colourations that we could not damp out as much as we tried ......................... The good news is that nobody has reported any such weirdness with this current version of the Karlflex cabinet......This up-to-date model uses a simple front chamber with the single stuffed Freddi-Mod tuned stub,. while the rear chamber also only has a single stuffed and tuned stub....This combination seems to do well, but i suggest employing the solid divider style braces anyhow just to keep any potential for undesirable resonant weirdness at an absolute minimum .. 🙂
MMJ,
thanks for pointing my nose to it! I thought the Schlager mod is the "mod du jour" 😀
Makes work certainly easier...
Ikea pillow stuffing is ok? Lining will be 1/2" felt, anyway.
thanks for pointing my nose to it! I thought the Schlager mod is the "mod du jour" 😀
Makes work certainly easier...
Ikea pillow stuffing is ok? Lining will be 1/2" felt, anyway.
I REALLY hate this edit timeout! 😡
Last post's first line should read
And this is what the double board baffle should look like:
Last post's first line should read
And this is what the double board baffle should look like:
I REALLY hate this edit timeout! 😡
Last post's first line should read
And this is what the double board baffle should look like:
Gkh,
We are unable to see the image at your link, perhaps it needs to be made public again? I remember this happened with some of your previous 3D image links ..
I really like your sketch at post #2050 , excellent, well braced 🙂
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Me too
The short edit timeout here in DIYaudio is definitely terrible..... It is one of the very few complaints i have about the way these forums work .... Other than that DIYaudio is mostly fantastic
I REALLY hate this edit timeout! 😡
The short edit timeout here in DIYaudio is definitely terrible..... It is one of the very few complaints i have about the way these forums work .... Other than that DIYaudio is mostly fantastic

Can you now see the 3D?
DIYaudio is certainly fantastic - I learned so much from reading here, and found out how much more I still have to learn...
DIYaudio is certainly fantastic - I learned so much from reading here, and found out how much more I still have to learn...
Falling down the Rabbit Hole
I cannot view the 3D images yet, i will try again in a few minutes
Realizing how much more there is to learn can be such a humbling experience , and it just seems to be a constant process as we spiral out and expand our knowledge .... Not sure if it ever ends, but i am not sure if i would ever want it to end because i am enjoying the journey
This rabbit hole goes deep!
Can you now see the 3D?
I cannot view the 3D images yet, i will try again in a few minutes
DIYaudio is certainly fantastic - I learned so much from reading here, and found out how much more I still have to learn...
Realizing how much more there is to learn can be such a humbling experience , and it just seems to be a constant process as we spiral out and expand our knowledge .... Not sure if it ever ends, but i am not sure if i would ever want it to end because i am enjoying the journey

This rabbit hole goes deep!

I cannot view the 3D images yet, i will try again in a few minutes
I don't understand this - made it public nearly two hours ago, checked now and it was marked as private again 😡 Seems Tinkercad has a slight hiccup. Please try this link.
Realizing how much more there is to learn can be such a humbling experience , and it just seems to be a constant process as we spiral out and expand our knowledge .... Not sure if it ever ends, but i am not sure if i would ever want it to end because i am enjoying the journey
This rabbit hole goes deep!
Neither would I want to stop learning, nor do I mind falling into the rabbit hole 😀
BTW, I've not made the angled sides yet. Have to talk to the CNC guys whether they can router them, first.
Let me know what you mean
Gkh,
Let me know what you mean... All angles in the Karlflex are 90 degrees except for the angle of the baffle, and the arc on the "aperture" (front panel , mouth area) ...
BTW, I've not made the angled sides yet. Have to talk to the CNC guys whether they can router them, first.
Gkh,
Let me know what you mean... All angles in the Karlflex are 90 degrees except for the angle of the baffle, and the arc on the "aperture" (front panel , mouth area) ...
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