Hi freddi,
Thanks for the additional picture. Is the 5.3" length above the flange, and how thick is the flange of the Transylvania K-tubes? Your schedule 40 pvc tube looks good. I make the slotted length 5.5", and left a 3/4" bottom stub to be cut to length during fitting of the tube to a flange.
Post #1760: "...is the tube on the left 1"ID? how did you manage the taper on the other tube?..."
Both were made using the development in Post #1754 (1/2 of an ellipse), the viewing angle makes them look different.
I used the fiberglass tubes I described in Post #1757: "... fiberglass tube that are ~ 1.020"O.D. w/ a .030"nom. wall. Rough measurements confirm that the I.D. is about .960" to .963"..."
I found some 2"I.D. cardboard tubes, those should be fine for the 12" long "von Langa" tubes (?).
Regards,
Thanks for the additional picture. Is the 5.3" length above the flange, and how thick is the flange of the Transylvania K-tubes? Your schedule 40 pvc tube looks good. I make the slotted length 5.5", and left a 3/4" bottom stub to be cut to length during fitting of the tube to a flange.
Post #1760: "...is the tube on the left 1"ID? how did you manage the taper on the other tube?..."
Both were made using the development in Post #1754 (1/2 of an ellipse), the viewing angle makes them look different.
I used the fiberglass tubes I described in Post #1757: "... fiberglass tube that are ~ 1.020"O.D. w/ a .030"nom. wall. Rough measurements confirm that the I.D. is about .960" to .963"..."
I found some 2"I.D. cardboard tubes, those should be fine for the 12" long "von Langa" tubes (?).
Regards,
the Transylvania tube I grabbed is roughly 5 3/16" above the recessed part of the flange - add about 1/8" and a hair to that for its overall length from throat to tip. This tube has a roller pin fitted crosswise (gotta charge my camera) for whatever craziness the makers seemed to think that made a difference. IIRC the late Ernst Beck had some tubes drilled but missing the roller pin so he thought the holes significant 
- once I get a picture, you can poke a little 1/8" diameter dowel piece down in the tube and wonder for yourself.
here's IG's Transylvania tube so you can see the recess on the flange - its a sturdy and reasonably inert affair.
I never had a functioning 2" format driver to try with a diy 2"x11" K-tube - ran it once with a 2.5" tv speaker on a wood adapter.
the flange's perimeter is about 1/4" thick, but the actual base thickness is closer to 1/8" - the widest part of the tube's aperture
is about 7/8"
- once I get a picture, you can poke a little 1/8" diameter dowel piece down in the tube and wonder for yourself.here's IG's Transylvania tube so you can see the recess on the flange - its a sturdy and reasonably inert affair.
I never had a functioning 2" format driver to try with a diy 2"x11" K-tube - ran it once with a 2.5" tv speaker on a wood adapter.
the flange's perimeter is about 1/4" thick, but the actual base thickness is closer to 1/8" - the widest part of the tube's aperture
is about 7/8"
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Hi freddi,
Thanks for the additional data. So we have 5-5/16" (5.3125"nom.) from K-tube throat to tip. Looking forward to your pictures of the roller pin. Maybe to kill some particular resonance peak?
I butchered a piece of 2"I.D. cardboard tube, that was easy enough. I cut the slot on one tube all the way through to the throat, and it's interesting to see, that you can open up the throat, and the section towards the tip does not seem to change. This may be one way to get some slope into the K-tube. I have the development attached in two parts, that way it fits on 8.5x11 paper using 1:1 scale. Again, it's for 2"I.D. and 12" length, 1/2 ellipse.
Regards,
Thanks for the additional data. So we have 5-5/16" (5.3125"nom.) from K-tube throat to tip. Looking forward to your pictures of the roller pin. Maybe to kill some particular resonance peak?
I butchered a piece of 2"I.D. cardboard tube, that was easy enough. I cut the slot on one tube all the way through to the throat, and it's interesting to see, that you can open up the throat, and the section towards the tip does not seem to change. This may be one way to get some slope into the K-tube. I have the development attached in two parts, that way it fits on 8.5x11 paper using 1:1 scale. Again, it's for 2"I.D. and 12" length, 1/2 ellipse.
Regards,
Attachments
Large vintage sectoral horns have such a majestic old-timey appearance
Tb46 ,
I like the look of the Altec 511B sectoral horns
About the slotted tube, your tube project looks like it is coming together well, i am sure that a compression driver which starts off with a flat-ish natural response could work well on a slotted tube with a 3rd order crossover ... Great for home or even out-and-about as instrument cabinet or small DJ PA rig depending on the scenario ....
For guidance on the contour of that slotted K-tube just copy the shape of this woman's cleavage:
She worked for the Transylvania Power Company
Hi MMJ,
Post #1756: "...the tube won't have the gain and consistent dispersion that this big CD horn has ...is a great affordable and easy-to-make combination..."
Thanks for the additional information.
I have a few Altec 511B horns on the shelf, and some of the old Altec 806a (?) drivers as well as the Selenium D220Ti (and some old JBL horn,I think. Too much stuff...). I don't have the time to set something up to make meaningfull comparisons, so I asked.
I see your reasoning for a simple crossover for a quick test; I like 3rd order crossovers for horns in general, also here is a quick reference to CD horn/waveguide EQ (you are probably aware of this, there is also a lot of stuff on audioheritage.com):
http://www.diyaudio.com/forums/mult...170m0-waveguide-experiment-4.html#post1378211
I have some fiberglass tube that are ~ 1.020"O.D. w/ a .030"nom. wall. Rough measurements confirm that the I.D. is about .960" to .963". I think that should be close enough for government work. Maybe I'll get around to butchering one of those.
Regards,
Tb46 ,
I like the look of the Altec 511B sectoral horns
About the slotted tube, your tube project looks like it is coming together well, i am sure that a compression driver which starts off with a flat-ish natural response could work well on a slotted tube with a 3rd order crossover ... Great for home or even out-and-about as instrument cabinet or small DJ PA rig depending on the scenario ....
For guidance on the contour of that slotted K-tube just copy the shape of this woman's cleavage:
She worked for the Transylvania Power Company
Complex Karlflex
Sebastian! ,
I am really looking forward to seeing what you end up with!! I have seen many of your scripts now and i know you were onto something good
That 10khz voicecoil inductance figure of .55mh will likely end up being something in the range of 1.3mh to 1.4mh at 1khz (the figure to plug into Akabak) ...
Hi there, update from Denmark. The Karlflex with multiple Freddi Stubs is taking form. But with everyday life intervening all the time, things progress in a somewhat slow pace
I have measured T/S for the 15LB100 and Le was 0,55 mH at 10k hz. When I simmed in Akabak the FR was up by 2db from 200 hz, comparred with the given specs, so yes I think it has sufficient output in the 1000-2000 hz. But in a near futuretime I'll have a more valid answer
View attachment 514904
Sebastian! ,
I am really looking forward to seeing what you end up with!! I have seen many of your scripts now and i know you were onto something good
That 10khz voicecoil inductance figure of .55mh will likely end up being something in the range of 1.3mh to 1.4mh at 1khz (the figure to plug into Akabak) ...
tb46 - I think someone at Transylvania thought the roller pin improved dispersion (?) The nice thing about a K-tube is that it needs no frequency response compensation at all. The best overall dispersion of its pattern mix is around 30 degrees elevation of the slot is facing "down" and 30 down if the slot is facing up.
MMJ - I see some protuberances in the model's form - JEK would approve
- what kind of contour would it take to make one of his mics ~"flat" ?
Karlson even drew protuberances at the ends of Klam, microphone and IIRC (?) K-tube microwave antenna
Here's a snippet from IG81 and whats left of one of his graphs as all I could find left was a thumbnail
this is just one trace with different smoothing and offsets
on another graph(not shown) comparing The Tube to a Smith Horn and homemade conical WG , IG said:
"Blue trace = Smith
Red trace = Woodhorn
Green trace = K-Tube
Of all three WG's the K-Tube measures best stock, with no comp network or physical tweaks"
MMJ - I see some protuberances in the model's form - JEK would approve
- what kind of contour would it take to make one of his mics ~"flat" ?
Karlson even drew protuberances at the ends of Klam, microphone and IIRC (?) K-tube microwave antenna
Here's a snippet from IG81 and whats left of one of his graphs as all I could find left was a thumbnail
this is just one trace with different smoothing and offsets
on another graph(not shown) comparing The Tube to a Smith Horn and homemade conical WG , IG said:
"Blue trace = Smith
Red trace = Woodhorn
Green trace = K-Tube
Of all three WG's the K-Tube measures best stock, with no comp network or physical tweaks"
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those "Protuberances" from Karlson's "Open End Waveguide Antenna" patent 3445852
"Protuberances 40 as shown in FIG. 9, may be used to improve the dispersion pattern for specific applications where uniform radiation intensity is required over large areas and where pencil beam type radiation would be inadequate at ver close ranges. These protuberances act to reflect energy of suffcient intensity to fill out the voids in the antenna pattern normally occuring at close ranges with narrow beam radiation. The size and placement of these protuberances are most easily located by experimental means"
"Protuberances 40 as shown in FIG. 9, may be used to improve the dispersion pattern for specific applications where uniform radiation intensity is required over large areas and where pencil beam type radiation would be inadequate at ver close ranges. These protuberances act to reflect energy of suffcient intensity to fill out the voids in the antenna pattern normally occuring at close ranges with narrow beam radiation. The size and placement of these protuberances are most easily located by experimental means"
Here's how the roller pin looks in Transylvania Power Company's "The Tube"
I think its a hair "above" tube center when viewed at the throat but my camera angle pretty much made it look ~dead center. A little 3/16" or a it larger hardwood dowel should do about the same effect (whatever that may be). If I can't find a missing plain tube to make a pair then may knock it out and fill the holes with epoxy.
The rear edge of the roller pin is ~5/8" down the tube as measured from the plate which bolts to the compression driver.
The roller pin seems ~3/16" diameter and assume its a standard diameter (?)
Roller pin throat view
Roller pin front of aperture view
Roller pin side of tube view
I think its a hair "above" tube center when viewed at the throat but my camera angle pretty much made it look ~dead center. A little 3/16" or a it larger hardwood dowel should do about the same effect (whatever that may be). If I can't find a missing plain tube to make a pair then may knock it out and fill the holes with epoxy.
The rear edge of the roller pin is ~5/8" down the tube as measured from the plate which bolts to the compression driver.
The roller pin seems ~3/16" diameter and assume its a standard diameter (?)
Roller pin throat view
Roller pin front of aperture view
Roller pin side of tube view
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If you want to try sometihng real short - make a mini klam like this one which Alan Weiss used for a theater speaker - it mounted to the old Eminence CD8 1" compression driver - I think the klam aperture angle is ~40 degrees up from horizontal
An externally hosted image should be here but it was not working when we last tested it.
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Hi freddi,
Great pictures of the roller pin and the Transylvania K-tube. Thanks. That should be measurable; but that will have to wait. Somewhere on the shelf should be a Stanford Acoustic SM3202 2" compression driver w/ horn. If I can find it, that should be a good test driver for the 2" K-tube. Maybe I can set something up this weekend, or over Thanksgiving.
Regards,
Great pictures of the roller pin and the Transylvania K-tube. Thanks. That should be measurable; but that will have to wait. Somewhere on the shelf should be a Stanford Acoustic SM3202 2" compression driver w/ horn. If I can find it, that should be a good test driver for the 2" K-tube. Maybe I can set something up this weekend, or over Thanksgiving.
Regards,
Hi MMJ,
Thanks for the technical derivation of the curves.
As to the 511B horns, they have to be properly mounted to reduce the bell-like ringing of the mouth/mounting flange. I still like the sound, I have usually tried to stay away from the 500Hz range, 700-800 sounds better to me. Once upon a time somebody in the El Paso area made fiberglass copies of the 811 horn w/o the ribs, and a much heavier wall; these sounded quite nice w/ JBL LE85 drivers. I've always threatened to give it a try on the 511s, but the stars just never lined up right.
Regards,
Thanks for the technical derivation of the curves.
As to the 511B horns, they have to be properly mounted to reduce the bell-like ringing of the mouth/mounting flange. I still like the sound, I have usually tried to stay away from the 500Hz range, 700-800 sounds better to me. Once upon a time somebody in the El Paso area made fiberglass copies of the 811 horn w/o the ribs, and a much heavier wall; these sounded quite nice w/ JBL LE85 drivers. I've always threatened to give it a try on the 511s, but the stars just never lined up right.
Regards,
hi tb46 - here's a comment from David A. Young on Karlsons and a homemade 2" tube lifted from Job Ulfman's old K-forum
RE: Whittling K-Tubes - freddyi - High Efficiency Speaker Asylum
RE: Whittling K-Tubes - freddyi - High Efficiency Speaker Asylum
fwiw I liked Atlas/Klipsch K55V and old University drivers on 511 with Klipsch sized caps using Klipsch/Crites autoformer attenuation - used to have on-axis measurements online vs other horns but think they're gone - might still be in an old pc - I liked the phenolic 1" driver as a mid better than running 511 mid-treble with 806a - think the pea-shooter dispersion at the top was too narrow to sound as natural as it should up close (?) 511 with a decent phenolic driver should make a good headbanger for stuff like AC/DC (my last tweeter was an Eminence APT150) - I remember it sounding pretty good too with Jack Sheldon's great old M&K cd "Playin' It Straight" which was mixed by Ken Kessel and Scott Simon - that's one of the best jazz trumpet playing albums I've heard - Sheldon had great ideas and chops in those days. Most of the band was from Carson's Tonight show.
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Would an Eminence Beta 15 work OKish in a 120liters enclosure?
I know it has a weak motor.
Specs: Eminence Beta-15A 15" Driver
I want to use it in 40-500Hz range - active XO. I will not push it hard. I know it has limited Xmax..
At the moment i have the Betas in H frame OB. But in H frame, they get muddy above 150Hz LR4 cut.
Above they will match a Tractrix frnt horn (Fc=220Hz) and a K-tube with D220Ti.
I know it has a weak motor.
Specs: Eminence Beta-15A 15" Driver
I want to use it in 40-500Hz range - active XO. I will not push it hard. I know it has limited Xmax..
At the moment i have the Betas in H frame OB. But in H frame, they get muddy above 150Hz LR4 cut.
Above they will match a Tractrix frnt horn (Fc=220Hz) and a K-tube with D220Ti.
I'm guessing Beta15A may just work in a 120 liter Karlflex - someone will have to simulate it.
here's approximate ground-plane of my Beta15cx which had similar specs to 15A in the old Karlson enclosure with a 40 square inch port - I think I made the rear shelf gap pretty small to subjectively tighten the bass so it would not "boom" on Mickey Hart's DAFOS track "Beast" drop. K15 is tuned higher than MMJ's Karlflex. Beta15a has a pretty big peak in tb46's little 74 liter cabinet.
here's approximate ground-plane of my Beta15cx which had similar specs to 15A in the old Karlson enclosure with a 40 square inch port - I think I made the rear shelf gap pretty small to subjectively tighten the bass so it would not "boom" on Mickey Hart's DAFOS track "Beast" drop. K15 is tuned higher than MMJ's Karlflex. Beta15a has a pretty big peak in tb46's little 74 liter cabinet.
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Fashion and function brought to you by the Transylvania Power Company
Ahh yes, no problem at all.
It is a little known fact that the slotted K-tube design was inspired by the aesthetically pleasing "PLUNGING NECKLINE" fashion worn by many female employees at the Transylvania Power Company.
another example:
and
and here (below) are some of the fine folks at TPC doing some very serious listening tests:
Hi MMJ,
Thanks for the technical derivation of the curves.
Regards,
Ahh yes, no problem at all.
It is a little known fact that the slotted K-tube design was inspired by the aesthetically pleasing "PLUNGING NECKLINE" fashion worn by many female employees at the Transylvania Power Company.
another example:
and
and here (below) are some of the fine folks at TPC doing some very serious listening tests:
Beta15
Arcgotic,
Unfortunately The Beta 15a is not a good choice if you strive for 40hz extension in a small cabinet because it lacks the motor strength to accomplish that, however the Beta15a does have an extraordinary rising upper-mid response so it can be used with K-wings for superior dispersion up to 2khz, and that driver's parameters are very suitable for strong midbass response in a small cabinet (just not subbass) ...... So it does seem like a fantastic candidate for a classic Karlson 15 cab as in Freddi's example of the "Karlson 15 copy" from #1775 ...
In my 120L Karlflex virtual model (tuned to 40hz) the Beta 15a has a bump in the response between 60hz and 80hz (-3db @ 55hz , -10db @40hz) , so it looks like a great midbass or midhorn+kickbin range cab effectively covering the 60hz to 2khz part of the spectrum... My Karlflex-12 prototype measures with very coherent phase response through this range and you can (and should) install a classic Karlson slot and wings on this design when using the Beta15a in the 120L Karlflex.......
You would probably want to employ a separate subwoofer in your system to handle the subbass frequencies in this case ..
Arcgotic,
Unfortunately The Beta 15a is not a good choice if you strive for 40hz extension in a small cabinet because it lacks the motor strength to accomplish that, however the Beta15a does have an extraordinary rising upper-mid response so it can be used with K-wings for superior dispersion up to 2khz, and that driver's parameters are very suitable for strong midbass response in a small cabinet (just not subbass) ...... So it does seem like a fantastic candidate for a classic Karlson 15 cab as in Freddi's example of the "Karlson 15 copy" from #1775 ...
In my 120L Karlflex virtual model (tuned to 40hz) the Beta 15a has a bump in the response between 60hz and 80hz (-3db @ 55hz , -10db @40hz) , so it looks like a great midbass or midhorn+kickbin range cab effectively covering the 60hz to 2khz part of the spectrum... My Karlflex-12 prototype measures with very coherent phase response through this range and you can (and should) install a classic Karlson slot and wings on this design when using the Beta15a in the 120L Karlflex.......
You would probably want to employ a separate subwoofer in your system to handle the subbass frequencies in this case ..
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Hi Matthew,
freddi has started a new K-tube thread here:
http://www.diyaudio.com/forums/multi-way/282456-nice-k-tube-tweeter.html
It should be primarily about the 2"I.D. K-tubes, but-as always-is drifting about a bit.
Partsexpress has the GRS PZ1188 on sale, do you think they would be suitable for the 1"I.D. K-tubes? Thought I ask the piezo expert. GRS PZ1188 Piezo Horn Driver Similar to KSN1188A
Regards,
freddi has started a new K-tube thread here:
http://www.diyaudio.com/forums/multi-way/282456-nice-k-tube-tweeter.html
It should be primarily about the 2"I.D. K-tubes, but-as always-is drifting about a bit.
Partsexpress has the GRS PZ1188 on sale, do you think they would be suitable for the 1"I.D. K-tubes? Thought I ask the piezo expert.
GRS PZ1188 Piezo Horn Driver Similar to KSN1188ARegards,