Good morning Freddy,
no, we haven't tried to combine a K-tube with baffle. To be honest those K-tubes are going surprisingly deep/low on their own. Till so far the woofer simply added the needed support so we never bothered.
And already with the current 2way system there is already more then enough bas/mid available so again the need is simply not there. Besides that the construction of a K-tube + baffle combo will be significantly larger then the current set up on the construction plate plus frames for the K-tubes.
Still amazed that there are almost no commercial version of that K-tube available. Maybe it looks funny but that's anly because we're accustomed to standard boxes.....soundwise there is nothing wrong with this technique.
Of course you have to pair the K-tube with a appropriate compression driver but that shouldn't be a problem. Just like combining horns with a compression driver: it's the combination that counts.
So with the K-tube we have great result with the FaitalPro HF10AK; and lousy results with the FaitalPro HF104. That doesn't mean those drivers are good or bad.....it's the combination that counts.
Regards,
Reinout
no, we haven't tried to combine a K-tube with baffle. To be honest those K-tubes are going surprisingly deep/low on their own. Till so far the woofer simply added the needed support so we never bothered.
And already with the current 2way system there is already more then enough bas/mid available so again the need is simply not there. Besides that the construction of a K-tube + baffle combo will be significantly larger then the current set up on the construction plate plus frames for the K-tubes.
Still amazed that there are almost no commercial version of that K-tube available. Maybe it looks funny but that's anly because we're accustomed to standard boxes.....soundwise there is nothing wrong with this technique.
Of course you have to pair the K-tube with a appropriate compression driver but that shouldn't be a problem. Just like combining horns with a compression driver: it's the combination that counts.
So with the K-tube we have great result with the FaitalPro HF10AK; and lousy results with the FaitalPro HF104. That doesn't mean those drivers are good or bad.....it's the combination that counts.
Regards,
Reinout
Good morning Reinout
regarding aesthetics, for short tubes which do not project beyond the woofer baffle, those might be hidden in a "cage" - say made of a wood base, four upright wood dowels wrapped with cloth.
One US K-experimenter has laminated maple veneer layers around a 1" diameter rod which he says forms a reasonably inert K-tube.
Your PVC/aluminum structure is a marvel.
It is odd no one makes a commercial K-tube.
Printed tubes, (especially the double-slot K-tube) could use triangular stiffening gussets/braces like on "The Tube".
Best wishes,
Freddy
regarding aesthetics, for short tubes which do not project beyond the woofer baffle, those might be hidden in a "cage" - say made of a wood base, four upright wood dowels wrapped with cloth.
One US K-experimenter has laminated maple veneer layers around a 1" diameter rod which he says forms a reasonably inert K-tube.
Your PVC/aluminum structure is a marvel.
It is odd no one makes a commercial K-tube.
Printed tubes, (especially the double-slot K-tube) could use triangular stiffening gussets/braces like on "The Tube".
Best wishes,
Freddy
has anyone here experimented with a tube shorter (smaller ID too) than "THE TUBE" to see and hear how that behaves as a super or helper tweeter ?
Alan Weiss scaled Karlson's klam as a tweeter lens *. That may have some use and worth a try.
https://i.imgur.com/DHWZgYR.jpg
* here's a 1944 application for a V slot microwave antenna similar - vice versa in form to the klam.
https://i.imgur.com/rYsfNkG.jpg
Alan Weiss scaled Karlson's klam as a tweeter lens *. That may have some use and worth a try.
https://i.imgur.com/DHWZgYR.jpg
* here's a 1944 application for a V slot microwave antenna similar - vice versa in form to the klam.
https://i.imgur.com/rYsfNkG.jpg
Good morning Egellings,
i guess you're right...the turntable weighs around 400 kgs (excluding compressor and associated pneumatics).
In this forum i started a thread with that turntable (Caeles-special; an air-bearing turntable )
Back to K-tubes: nope.....never explored smaller diameters. The 1" drivers are a common standard; going smaller than that leaves you with very very little choice ? Or you have to fit a throat convertor.
Regards,
Reinout
i guess you're right...the turntable weighs around 400 kgs (excluding compressor and associated pneumatics).
In this forum i started a thread with that turntable (Caeles-special; an air-bearing turntable )
Back to K-tubes: nope.....never explored smaller diameters. The 1" drivers are a common standard; going smaller than that leaves you with very very little choice ? Or you have to fit a throat convertor.
Regards,
Reinout
Hi Reinout
I should have just said "shorter". Can tube length shorter than "The Tube" be useful? (We have the mini-klam variant by Alan Weiss} Here's a thinwall pvc tube cut short.
https://i.imgur.com/cQiMaF0.jpg
With large diameter tubes, one could make a diagonal slice, then attach a flat plate. Then a tapered slot can be cut in that plate. That's the way Bose show's it in one patent and perhaps a way to try with some cone drivers. (Bose gives no reference to Karlson)
US8351630B2 - Passive directional acoustical radiating
- Google Patents
https://patentimages.storage.googleapis.com/US8351630B2/US08351630-20130108-D00003.png
For a number of years I've suggested for folks to try a K-tube - but surprisingly, few have done it.
I've never heard a 2 inch tube with proper driver, only with small cone, or 1 inch compression driver w. 1 to 2 inch adapter.
What might you use on that huge looking tube?
Best Wishes,
Freddy
I should have just said "shorter". Can tube length shorter than "The Tube" be useful? (We have the mini-klam variant by Alan Weiss} Here's a thinwall pvc tube cut short.
https://i.imgur.com/cQiMaF0.jpg
With large diameter tubes, one could make a diagonal slice, then attach a flat plate. Then a tapered slot can be cut in that plate. That's the way Bose show's it in one patent and perhaps a way to try with some cone drivers. (Bose gives no reference to Karlson)
US8351630B2 - Passive directional acoustical radiating
- Google Patents
https://patentimages.storage.googleapis.com/US8351630B2/US08351630-20130108-D00003.png
For a number of years I've suggested for folks to try a K-tube - but surprisingly, few have done it.
I've never heard a 2 inch tube with proper driver, only with small cone, or 1 inch compression driver w. 1 to 2 inch adapter.
What might you use on that huge looking tube?
Best Wishes,
Freddy
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Good morning Freddy,
i have a couple of 2" compression drivers available. So i don't need a throat-convertor.
If everything works out allright i should go from 2 to 3 ways this weekend.....
The Fostex D200A has the best chance for good results; we simply have to see.
Pictures included of that D200A (open/closed/next to 1" and 2" K-tubes).
Also a picture where you can see the other 2" drivers.
Looking forward to this weekend !
Regards,
Reinout
i have a couple of 2" compression drivers available. So i don't need a throat-convertor.
If everything works out allright i should go from 2 to 3 ways this weekend.....
The Fostex D200A has the best chance for good results; we simply have to see.
Pictures included of that D200A (open/closed/next to 1" and 2" K-tubes).
Also a picture where you can see the other 2" drivers.
Looking forward to this weekend !
Regards,
Reinout
Attachments
Hurray, the metalwork is finished so i can start assembling the Karlson-frames. And they are needed as the Fostex-driver + 2" K-tube does weigh in at 20 kgs.....
The frames are made from 15 mm aluminium, waterjet-cut so shockingly sharp. It did cost some time to get this stuff more manageble.
From an audio-collegue i could have a tube amp on loan so:
- the Fertin woofer is powerd by my 35TG 8 W amp;
- the Fostex + 2" K-tube is powered by my 6C45 2,6 W amp;
- the Von Langs + 1" K-tube is powered by a 1,1 W E2c amp.
More then enough.
With the use of a Behringer crossover i found out the XO-freqs fast: low/mid in the 500-550 Hz and the mid/high in the 4000-4500 Hz.
That Behringer is a useful toll but not really audio. I'll find another solution for that.
So it's up-and-running and i'm pleased with the result: great soundstage/presentation, oodles of bass and very very direct. There is no hiding possible.
When all crossover-parts are in i'll start with the aligning of the K-tubes.
Regards,
Reinout
The frames are made from 15 mm aluminium, waterjet-cut so shockingly sharp. It did cost some time to get this stuff more manageble.
From an audio-collegue i could have a tube amp on loan so:
- the Fertin woofer is powerd by my 35TG 8 W amp;
- the Fostex + 2" K-tube is powered by my 6C45 2,6 W amp;
- the Von Langs + 1" K-tube is powered by a 1,1 W E2c amp.
More then enough.
With the use of a Behringer crossover i found out the XO-freqs fast: low/mid in the 500-550 Hz and the mid/high in the 4000-4500 Hz.
That Behringer is a useful toll but not really audio. I'll find another solution for that.
So it's up-and-running and i'm pleased with the result: great soundstage/presentation, oodles of bass and very very direct. There is no hiding possible.
When all crossover-parts are in i'll start with the aligning of the K-tubes.
Regards,
Reinout
Attachments
Good morning Freddy,
thanks for the nice words. I will pass it to our audio-group as this is claerly a team-effort. At this level you can not do everything on your own and the help / knowledge / materials of others is essential for that next step.
The K-tubes are simply supersized. Sizewise it is just larger; not different. That being said the current large K-tube is made as a 3" version (to be fitted with a convertor to the 2" driver throat). The reason is very simple: we couldn't find the proper 2" material but did find nice 3" stuff.....
With our experiments we found out that resonances in the K-tube are a nightmare and to be avoided. That means seriously adapting the 3D-print. Simply making it heavier did decrease the resonances but lesser than expected/hoped. The best way for reonance control was stacking different materials so we went on looking for 2 tubes that fit perfectly in each other.
So the inside of my 3" K-tube is made from layered polypropylene and outside is made of aluminium. If you look closely at the picture at the blue plastic you can see the layering inside the plastic.
My audio-collegue doesn't have the original THE TUBE so he made a 1" K-tube himself on the same principle: 2 totally different materials (alu outside, plastic inside) and even the inside plastic is layered. See picture; white plastic.
And to be honest: that K-tube is simply better then my original......
Regards,
Reinout
thanks for the nice words. I will pass it to our audio-group as this is claerly a team-effort. At this level you can not do everything on your own and the help / knowledge / materials of others is essential for that next step.
The K-tubes are simply supersized. Sizewise it is just larger; not different. That being said the current large K-tube is made as a 3" version (to be fitted with a convertor to the 2" driver throat). The reason is very simple: we couldn't find the proper 2" material but did find nice 3" stuff.....
With our experiments we found out that resonances in the K-tube are a nightmare and to be avoided. That means seriously adapting the 3D-print. Simply making it heavier did decrease the resonances but lesser than expected/hoped. The best way for reonance control was stacking different materials so we went on looking for 2 tubes that fit perfectly in each other.
So the inside of my 3" K-tube is made from layered polypropylene and outside is made of aluminium. If you look closely at the picture at the blue plastic you can see the layering inside the plastic.
My audio-collegue doesn't have the original THE TUBE so he made a 1" K-tube himself on the same principle: 2 totally different materials (alu outside, plastic inside) and even the inside plastic is layered. See picture; white plastic.
And to be honest: that K-tube is simply better then my original......
Regards,
Reinout
Attachments
Hi Reinout,
That one inch K-tube looks great. Did your team also investigate the little klam? It would not have much air load but I gave a printed one inch format version a brief listen with Altec "Symbiotic" 808 and thought it could have merit for certain applications,
Best Wishes,
Freddy
HIU's picture of a set of Alan Weiss's klam lenses
https://www.diyaudio.com/forums/att...ers-3326aca9-e1d9-468b-8ec7-96d57dfac207-jpeg
That one inch K-tube looks great. Did your team also investigate the little klam? It would not have much air load but I gave a printed one inch format version a brief listen with Altec "Symbiotic" 808 and thought it could have merit for certain applications,
Best Wishes,
Freddy
HIU's picture of a set of Alan Weiss's klam lenses
https://www.diyaudio.com/forums/att...ers-3326aca9-e1d9-468b-8ec7-96d57dfac207-jpeg
Thank you for reply.
Good to know but hard to imagine that these can be excited by the driver.
Currently I own a commercial K-tube only.
As I understand your large tube is just scaled according to this ?
Freddy asked if somebody is using a shorter version of the "coupler", yes,
I know semi commercial builds in this area, super tweeters with TAD driver.
Good to know but hard to imagine that these can be excited by the driver.
Currently I own a commercial K-tube only.
As I understand your large tube is just scaled according to this ?
Freddy asked if somebody is using a shorter version of the "coupler", yes,
I know semi commercial builds in this area, super tweeters with TAD driver.
Hi as_audio
regarding the shorter coupler, is that in a tube form ? or the mini-"klam" form as with the Weiss & Brown patent below ? I think the mini -klam may work well for above ear level applications as shown in the patent with a 15 foot elevation. A story goes that this lens under evaluation was rejected as "sprayed highs everywhere" vs THX directivity standards. There was another story that "the mob" sabotaged the system back in the days of Ulfman's Karlson forum.
https://patentimages.storage.googleapis.com/6f/f7/f8/6865aa5fd0da26/US5943431.pdf
regarding the shorter coupler, is that in a tube form ? or the mini-"klam" form as with the Weiss & Brown patent below ? I think the mini -klam may work well for above ear level applications as shown in the patent with a 15 foot elevation. A story goes that this lens under evaluation was rejected as "sprayed highs everywhere" vs THX directivity standards. There was another story that "the mob" sabotaged the system back in the days of Ulfman's Karlson forum.
https://patentimages.storage.googleapis.com/6f/f7/f8/6865aa5fd0da26/US5943431.pdf
Thanks. About how long was that short tube and what proportion of it was slotted? One K-experimenter once posted dimensions for a 1.5" ID K-tube which was 4.5" long with 3" length slot. I believe it slipped over the threaded portion of Eminence's APT50 phenolic diaphragm compression driver. IIRC its "nose" was cut "square" - like one would see if they truncated "THE TUBE" going back from its tip.
Here's an ultra low resolution picture of an Acoustic Reality brand lens from years ago. It was used in a small sealed box with Eminence's Beta 8 and the compression driver was an Eminence 1" bolt on. In those says, Eminence's compression driver only extended to around 12.5KHz, and had an aluminum diaphragm. Sometimes those were subjectively preferred to the later titanium diaphragm.
https://i.imgur.com/PYRH9Ig.jpg
A 1944 British microwave patent application is the closest thing I've seen yet for ancestor of the clam/klam. (other than an ancient water sprinkler nozzle). It was referenced in Karlson's Open End Waveguide Antenna patent which relates also to acoustic K-tube.
Here's an ultra low resolution picture of an Acoustic Reality brand lens from years ago. It was used in a small sealed box with Eminence's Beta 8 and the compression driver was an Eminence 1" bolt on. In those says, Eminence's compression driver only extended to around 12.5KHz, and had an aluminum diaphragm. Sometimes those were subjectively preferred to the later titanium diaphragm.
https://i.imgur.com/PYRH9Ig.jpg
A 1944 British microwave patent application is the closest thing I've seen yet for ancestor of the clam/klam. (other than an ancient water sprinkler nozzle
). It was referenced in Karlson's Open End Waveguide Antenna patent which relates also to acoustic K-tube.
Hi ReinoutdV and as_audio
do either of you know of folks experimenting with "K15 style" bass - midbass couplers who might share some findings - or at least give some hints towards what works best for them? Some of my K-type have been very good sounding, some including Karlson's originals, can sound very good to very bad depending upon the speaker chosen. (assuming no EQ applied)
Some couplers measure fairly well, others may exhibit a couple of deep dips.
GregB's "Karlsonator" with its offset driver solved a lot of problems. Transyvania Power Company's X15 box plays well but its not known how it would behave scaled. A stub connected to the top of K15 type can add volume to the front chamber and help tame the first peak.
The curved reflector and cavity shape it can present are another unknowns. One builder said his X15 size cabinet made with a fully curved reflector was an improvement over his earlier builds with several flat panels for the reflector, (all of his builds have the K-tube mounted internally)
I've had several K turn out pretty well - but other than intuition, and messing with them, don't fully know how to design the thing. (IMO they should be listenable without resorting to front cavity damping materials)
Certainly a poor choice in driver can ruin results.
Best,
Freddy
do either of you know of folks experimenting with "K15 style" bass - midbass couplers who might share some findings - or at least give some hints towards what works best for them? Some of my K-type have been very good sounding, some including Karlson's originals, can sound very good to very bad depending upon the speaker chosen. (assuming no EQ applied)
Some couplers measure fairly well, others may exhibit a couple of deep dips.
GregB's "Karlsonator" with its offset driver solved a lot of problems. Transyvania Power Company's X15 box plays well but its not known how it would behave scaled. A stub connected to the top of K15 type can add volume to the front chamber and help tame the first peak.
The curved reflector and cavity shape it can present are another unknowns. One builder said his X15 size cabinet made with a fully curved reflector was an improvement over his earlier builds with several flat panels for the reflector, (all of his builds have the K-tube mounted internally)
I've had several K turn out pretty well - but other than intuition, and messing with them, don't fully know how to design the thing. (IMO they should be listenable without resorting to front cavity damping materials)
Certainly a poor choice in driver can ruin results.
Best,
Freddy