Thanks. Would scaling GregB's Karlsonator 8's height be all that's needed to tune it better to FE206EN? What would be the effect of blocking off the stub right above the woofer? (other than worsening overall response)
I was hoping X would answer so I could learn more from him. I learnt a lot from his models on Kcoupler speakers. We classify speakers as bass-reflex, DCR ,transmission line,etc when we recognise what is the important property that determines the character of the speaker.
for instance a bass-reflex is determined by its volume and the air in the tube coupling the volume to the outside. Martin King has a paper explaining why a ML- TQWT is different from bass-reflex.
The karlsonator is a ML-TQWT with a Kcoupler. if you block off the stub of a karlsonator you are changing it into an XKi. As X mentioned scaling appears to work well for karsonators. I think this is because quarter-wave resonance is dominant and that is defined by its length. Karlsonators like bass-reflex have a helmholtz resonator. Scaling is less suitable because volume is proportional to L-cubed. I hope this makes sense
for instance a bass-reflex is determined by its volume and the air in the tube coupling the volume to the outside. Martin King has a paper explaining why a ML- TQWT is different from bass-reflex.
The karlsonator is a ML-TQWT with a Kcoupler. if you block off the stub of a karlsonator you are changing it into an XKi. As X mentioned scaling appears to work well for karsonators. I think this is because quarter-wave resonance is dominant and that is defined by its length. Karlsonators like bass-reflex have a helmholtz resonator. Scaling is less suitable because volume is proportional to L-cubed. I hope this makes sense
that makes sense and pretty well illustrates the limitations of (down) scaling a conventional Karlson cabinet. Also, like most other designs, there are practical limits as to how large to make a regular style K and keep it competitive.
one thing I've noticed about K15 - if one is playing and another K15 sitting in the room, and not connected (and coil not shunted) - the K not hooked up will play bass over a wide range - not just one note (even some lower mids) - does that happen with a reflex box?
(maybe X will eventually comment on scaling Karlsontor8's height and tuning ? - blocking off the stub and tuning ?)
one thing I've noticed about K15 - if one is playing and another K15 sitting in the room, and not connected (and coil not shunted) - the K not hooked up will play bass over a wide range - not just one note (even some lower mids) - does that happen with a reflex box?
(maybe X will eventually comment on scaling Karlsontor8's height and tuning ? - blocking off the stub and tuning ?)
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- of course, when we use higher Qts drivers, a regular K with sealed back chamber would allow some smaller couplers to work.
Hi there,
I've been trying to read up on all the Karlson based threads as I have some TC9FD's coming to experiment with and found the Mini-Karlsonator thread when searching.
However, I have a couple of 8" drivers to play with that I've used for OB but wanted to try something else with. Can I just use the 8" plans on post #1 or do I need a modified enclosure?
Visaton B200
T/S params here: B 200 - 6 Ohm | Visaton
and the Betsy WoW (without whizzer): Wild Burro Audio Labs - Fullrange Speakers - The Betsy & Betsy-K Drivers
I have a Beyma TPL-150 to experiment with too. Would either of these 8" drivers be suitable?
I've been trying to read up on all the Karlson based threads as I have some TC9FD's coming to experiment with and found the Mini-Karlsonator thread when searching.
However, I have a couple of 8" drivers to play with that I've used for OB but wanted to try something else with. Can I just use the 8" plans on post #1 or do I need a modified enclosure?
Visaton B200
T/S params here: B 200 - 6 Ohm | Visaton
and the Betsy WoW (without whizzer): Wild Burro Audio Labs - Fullrange Speakers - The Betsy & Betsy-K Drivers
I have a Beyma TPL-150 to experiment with too. Would either of these 8" drivers be suitable?
those qts figures are pushing it for any vented enclosure -but probably not so bad in practice. Transient response will be sacrificed vs lower qts. My L.Cao F6 has Qts ~0.7 and plays subjectively pretty well in a Karlsonator6 size as its quite efficient in the mids and highs. (louder than an Eminence Delta Pro8A rated 97.8dB) You can play with the damping material to some degree. xrk971 may have some opinions on your drivers regarding use in the Karlsonator type.
You can make regular Karlson type with aperiodic venting or sealed for some cases of drivers.
You can make regular Karlson type with aperiodic venting or sealed for some cases of drivers.
Thanks Freddi, but I was looking at the TC9FD which has a Qts of 0.89 so I was confused by the comments of low/medium Q being preferred.
Super Kurvy Karlsonator idea from GregB
with GB's Karlsonator 6 as an example - - (I'm not sure what the curved aperture might do overall)
with GB's Karlsonator 6 as an example - - (I'm not sure what the curved aperture might do overall)

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Figured this would be a good place to ask, so here goes!
I just managed to grab a pair of these feastrex clones at the Burning Amp 2018 raffle- UR330B8-11F.
A poor man Feastrex !
From what I gather they are made by Soucharm. Little other info appears to be available on them.
And here are the only listed parameters-
Impedance : 8 Ohm
Minimum Frequency Response
: 34 Hz
Reproduction Frequency Response
: Fo~18K
S.P.L. : 92.806 dB/W(m)
Rated Input : 30W
Music Power : 45W
Equivalent Diaghram Radius
: 132mm
Equivalent Mass : 26.419 g
Magnet Weight : 1100g
Net Weight : 11900 g
Fs : 34.942 Hz
Re : 7.2 Ohm
Mms : 32.964 g
BL : 8.135 TM
Qts : 0.691
Qms : 5.647
Qes : 0.787
Vas : 228.816 Ltr
I really, really hope these would work in a Karlsonator 12 or similar size cabinet, and have also attached the PDF of the frequency response.
My only concern is that due to the large magnet/rear assembly, some modifications may need to be made to the overall design, possibly stretching the area behind the driver to accommodate it. Maybe the volume of the magnet would need to be taken into account anyway, and the cabinet made correspondingly larger?
Hey XRK971, you mind doing a sim? I'm almost thinking a Karlsonator 12 scaled larger in depth, and maybe height would work for these?
I just managed to grab a pair of these feastrex clones at the Burning Amp 2018 raffle- UR330B8-11F.
A poor man Feastrex !
From what I gather they are made by Soucharm. Little other info appears to be available on them.
And here are the only listed parameters-
Impedance : 8 Ohm
Minimum Frequency Response
: 34 Hz
Reproduction Frequency Response
: Fo~18K
S.P.L. : 92.806 dB/W(m)
Rated Input : 30W
Music Power : 45W
Equivalent Diaghram Radius
: 132mm
Equivalent Mass : 26.419 g
Magnet Weight : 1100g
Net Weight : 11900 g
Fs : 34.942 Hz
Re : 7.2 Ohm
Mms : 32.964 g
BL : 8.135 TM
Qts : 0.691
Qms : 5.647
Qes : 0.787
Vas : 228.816 Ltr
I really, really hope these would work in a Karlsonator 12 or similar size cabinet, and have also attached the PDF of the frequency response.
My only concern is that due to the large magnet/rear assembly, some modifications may need to be made to the overall design, possibly stretching the area behind the driver to accommodate it. Maybe the volume of the magnet would need to be taken into account anyway, and the cabinet made correspondingly larger?
Hey XRK971, you mind doing a sim? I'm almost thinking a Karlsonator 12 scaled larger in depth, and maybe height would work for these?
Attachments
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That’s a great raffle prize! The Vas seems large - but give me a few days to do sim. I don’t have Akabak anymore on my work computer.
Thanks 🙂
For anybody interested in how they look, here's a listing for them-
Aucharm聲韻發燒8寸全頻喇叭鋼磁真正鈷磁全頻HIFIEND寬頻揚聲器
They seem pretty expensive!
For anybody interested in how they look, here's a listing for them-
Aucharm聲韻發燒8寸全頻喇叭鋼磁真正鈷磁全頻HIFIEND寬頻揚聲器
They seem pretty expensive!
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Disregard last post, that's the 8" version. These are the 12" version that I have-
声韵12寸全频钴磁喇叭hifi发烧钢磁铝镍钴扬声器超古董全频非同轴
声韵12寸全频钴磁喇叭hifi发烧钢磁铝镍钴扬声器超古董全频非同轴
So, I couldn't help myself, and felt like testing out these drivers (12" UR330B8-11F) so I hooked them up on the workbench, no baffle, no nothing.
They sound absolutely wonderful, lack of bass from being open air of course taken into account. The shadowed areas of the off-white cone show an eery sage/greenish tinge, that is quite pleasant too. Very natural sound from a whizzer cone. Aluminum phase plug.
I can't wait to build these up into a huge K if they will work!
Posting some pics. I have a ubiquitous Vifa TC9FD for size comparison.
They sound absolutely wonderful, lack of bass from being open air of course taken into account. The shadowed areas of the off-white cone show an eery sage/greenish tinge, that is quite pleasant too. Very natural sound from a whizzer cone. Aluminum phase plug.
I can't wait to build these up into a huge K if they will work!
Posting some pics. I have a ubiquitous Vifa TC9FD for size comparison.
Attachments
Figured this would be a good place to ask, so here goes!
I just managed to grab a pair of these feastrex clones at the Burning Amp 2018 raffle- UR330B8-11F.
A poor man Feastrex !
From what I gather they are made by Soucharm. Little other info appears to be available on them.
And here are the only listed parameters-
Impedance : 8 Ohm
Minimum Frequency Response
: 34 Hz
Reproduction Frequency Response
: Fo~18K
S.P.L. : 92.806 dB/W(m)
Rated Input : 30W
Music Power : 45W
Equivalent Diaghram Radius
: 132mm
Equivalent Mass : 26.419 g
Magnet Weight : 1100g
Net Weight : 11900 g
Fs : 34.942 Hz
Re : 7.2 Ohm
Mms : 32.964 g
BL : 8.135 TM
Qts : 0.691
Qms : 5.647
Qes : 0.787
Vas : 228.816 Ltr
I really, really hope these would work in a Karlsonator 12 or similar size cabinet, and have also attached the PDF of the frequency response.
My only concern is that due to the large magnet/rear assembly, some modifications may need to be made to the overall design, possibly stretching the area behind the driver to accommodate it. Maybe the volume of the magnet would need to be taken into account anyway, and the cabinet made correspondingly larger?
Hey XRK971, you mind doing a sim? I'm almost thinking a Karlsonator 12 scaled larger in depth, and maybe height would work for these?
I just ran the simulations for this driver and it is not really suited for a Karlsonator, as I suspected. In a normal 1.0x scale (standard 12in Karlsonator as designed by GregB) the volume is too small and there is a huge bass overshoot around 50Hz and a big dip at 150Hz. As you scale up to a rather large 1.5x scale cabinet, it still doesn't look great. If I make it 2.0x scale in height and depth and 1.5x in width, it is a bit better but still not the best. These are terribly huge cabinets and I would not recommend it. I would use these for their intended purpose in maybe something like the cabinet used in a Saba Greencone (tear shaped cross section largish volume - make same as Vas at 229L and open bottom with a 2in gap from floor) or Rondo.
Here are the predicted frequency responses at various scales:
Here is a Rondo (open bottom):

Maybe 16in W x 24in deep x 60 in tall... 4in gap on floor.
Attachments
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Well, darn 🙁
I figured it was a bit high Qts and would be large, but that response graph looks pretty funky and would likely need lots of EQ (which I'm not really set up for, or too hot on other than BSC or analog solutions) and it would be prohibitively large for sure.
Maybe I'll make a new thread for them and see what the groupthink ideas will come up with for any other possible box designs. I like those Rondo styles, but I'm not set up to do anything advanced in woodworking, like bent panels and curves.
Hmmm. Thanks for taking the time to check it out for me!
I figured it was a bit high Qts and would be large, but that response graph looks pretty funky and would likely need lots of EQ (which I'm not really set up for, or too hot on other than BSC or analog solutions) and it would be prohibitively large for sure.
Maybe I'll make a new thread for them and see what the groupthink ideas will come up with for any other possible box designs. I like those Rondo styles, but I'm not set up to do anything advanced in woodworking, like bent panels and curves.
Hmmm. Thanks for taking the time to check it out for me!
You can Rondo as a rectangular prism and no one will think it for the worse... But perhaps an OB is the best fit for these?
Hmmm. Maybe a folded rondo type may work? Would have to get creative to keep the internal shapes correct...
Well, to not clutter up this thread I went ahead and started another specifically for these drivers-
Aucharm UR330B8-11F full range 12" cabinet ideas?
We now return to your regularly scheduled programming 🙂
Well, to not clutter up this thread I went ahead and started another specifically for these drivers-
Aucharm UR330B8-11F full range 12" cabinet ideas?
We now return to your regularly scheduled programming 🙂
....Vas at 229L and open bottom with a 2in gap from floor) Maybe 16in W x 24in deep x 60 in tall... 4in gap on floor.
Call me old fashioned, but vintage type drivers seem to work well in vintage spec cabs with best overall power handling short of a BLH, especially if tube driven, so thinking a Vb = Vas/1.44 tuned with a vent area [Av] = [Sd] and damped to 'taste'. Worst case is one winds up stuffing it enough to be a 'Pensil' type alignment.
Assuming a ~38" seated ear height minus 1.5" thick base = ~63.37" x ~153.14"^2 WxD, ~547.39"2 vent x 0.75" baffle thickness with driver, vent offset = ~26.87", ~53.74" from top. All dims inside [i.d.].
GM
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you could poke one in a sealed box - for the cap to work, amp output Z needs to be low
a semi open back box (one patent showed a "K" slot)- maybe aperiodic
I think it would work in a sealed - aperiodic vent back chamber K - my Fane 12FR didn't have any noticeable peaking (nor bass) in a K12 with slit vents damped
GM's idea sounds good - lots of wood - What would G.A. Briggs done for this speaker?
a semi open back box (one patent showed a "K" slot)- maybe aperiodic
I think it would work in a sealed - aperiodic vent back chamber K - my Fane 12FR didn't have any noticeable peaking (nor bass) in a K12 with slit vents damped
GM's idea sounds good - lots of wood - What would G.A. Briggs done for this speaker?

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