since Karlson's reflector quesion didn't gain traction - how might it be "focused"?
(can't see how to delete - my typing isn't helped by numb fingers)
when using Karlson's "Fig.6" reflector, is there a way beforehand to roughly determine how to focus it for best result ? (which assume is to get some of the bounced energy out of the aperture)
I do have a curved upper reflector in my tall K18 and its sound quality is very good for the rather bizarre complement of H-coupled 18 plus 1-inch compression driver on a slotted pipe.
(Karlson did ray tracing)
from my limited experience, if the cavity is too deep relative to
its other dimensions, response problems may arise. K15 used a front "shelf" feature to offset that problem.
Auto putty such as Bondo might be used to curve sidewall to baffle and upper reflector junctions. I think the effect would be audible.
(can't see how to delete - my typing isn't helped by numb fingers)
when using Karlson's "Fig.6" reflector, is there a way beforehand to roughly determine how to focus it for best result ? (which assume is to get some of the bounced energy out of the aperture)
I do have a curved upper reflector in my tall K18 and its sound quality is very good for the rather bizarre complement of H-coupled 18 plus 1-inch compression driver on a slotted pipe.
(Karlson did ray tracing)
from my limited experience, if the cavity is too deep relative to
its other dimensions, response problems may arise. K15 used a front "shelf" feature to offset that problem.
Auto putty such as Bondo might be used to curve sidewall to baffle and upper reflector junctions. I think the effect would be audible.
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my favorite sounding K-Line hybrid Karlson's had a five step curve not unlike what your drawing shows with the line entering the front chamber at the top front of the cabinet. These ran a Fostex FE126. They were capable of simply astounding stage and image especially when laid on their sides at ear level with the open end of the cabinets facing toward the side walls. The recordings presentation it seemed was pasted over the room you were in and you felt that with each different recording you were listening in a different room. I took those to the 2004 Rocky Mountian Audio Show and demonstrated them.
Hi Moray - - I think these days one might be able to simulate the low frequency response of your K-T-Line with Hornresp and perhaps Circlomanen with his "ROAR" cabinet could help as think is somewhat similar.
What do you think the curved reflector should look like for a 10" K using regular technique which is to say would only be around 22" tall and perhaps 14-15" wide?
We mustn't let the K be forgotten as when implemented well, can be an excellent performer
with perhaps psycho-acoustic attributes which made them more realistic sounding than direct-radiator.
What do you think the curved reflector should look like for a 10" K using regular technique which is to say would only be around 22" tall and perhaps 14-15" wide?
We mustn't let the K be forgotten as when implemented well, can be an excellent performer
with perhaps psycho-acoustic attributes which made them more realistic sounding than direct-radiator.
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Yes you found the drawing! I built a second set of the first version you showed where the vent that coupled was at the top of the cabinet rather than just above the woofer. Both worked well but I liked the second version a little bit better because the line measured a little longer but we are only talking inches. So my preference may have been a simple bias, as I said bot versions were very good. I will have to down load my old drawing thanks for posting Fred. In other builds after these I would stop the tapers and curl them out just above the woofer which got rid of that cupped resonance that could sometimes occur with tapers which extended to the bottom of the cabinet.
There's the question of whether to use absorbent materials in the front chamber. Wish some drivers and original Karlson, its fine to have nothing in the front chamber, and some users such as Carl, app;lied many coats of shellac or varnish in the front chamber per John Karlson's instructions. I suspect a sealant on the wood is ok for the reflector/baffle. Perhaps Karlson was taking into account that most owners would have grill cloth.
Did you try any damping material on the inside of the wings?
When re-reading Karlson's 1961 letter to the late Martin C. Poppe (which I linked in the subwoofer form), Karlson discussed the difficulties of getting the chambers and shelves right to minimize destructive interference. Also, the K12 was said at that time to have a parabolic front chamber shape, so I assume that meant the K12 introduced sometime in 1956 then published as a construction article in he July 1958 issue of Popular Mechanics.
Its interesting that someone created the "Dutch K12" which went agaiinst Karlson's 2nd Acoustic Transducers patent installment with a perpendicular port panel rather than Karlson's curved panels. Perhaps the perpendicular panel may give a smoother response (?)
BTW, although X15 with a typical high efficiency 15" rolls off below ~80Hz like a K12 with similar 12", cone excursion is about half
with a 15" vs 12 and its a nice size to use with real subwoofers which nowdays are easy to design and can extend deep.
I assume TB46 has passed away - the X16 size sketch with K12 style panels is probably his.
Did you try any damping material on the inside of the wings?
When re-reading Karlson's 1961 letter to the late Martin C. Poppe (which I linked in the subwoofer form), Karlson discussed the difficulties of getting the chambers and shelves right to minimize destructive interference. Also, the K12 was said at that time to have a parabolic front chamber shape, so I assume that meant the K12 introduced sometime in 1956 then published as a construction article in he July 1958 issue of Popular Mechanics.
Its interesting that someone created the "Dutch K12" which went agaiinst Karlson's 2nd Acoustic Transducers patent installment with a perpendicular port panel rather than Karlson's curved panels. Perhaps the perpendicular panel may give a smoother response (?)
BTW, although X15 with a typical high efficiency 15" rolls off below ~80Hz like a K12 with similar 12", cone excursion is about half
with a 15" vs 12 and its a nice size to use with real subwoofers which nowdays are easy to design and can extend deep.
I assume TB46 has passed away - the X16 size sketch with K12 style panels is probably his.
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I know how you [don't] feel.
Right, he knew that parabolic lens are used for high intensity lighting, radar, etc., so for simple WGs these lens can work well if properly sized for the driver's polar response, so if you can angle cut these metal 'cans' to add a K-baffle you could experiment with different angles to find the optimum.
GM
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(so sorry on the "feeling" - it puts any notions of guitar playing to rest and probably bad for holding on to handlebars ). I guess at low levels, maybe a couple of layers of posterboard could make a reflector which might bend a little. That thin sign material seen for political signs ("coroplast"??), another.
). I guess at low levels, maybe a couple of layers of posterboard could make a reflector which might bend a little. That thin sign material seen for political signs ("coroplast"??), another.
Carl N. is the godfather of high aspect K, curved reflectors, cavity shape analysis, etc. but unfortunately, everything is a sekret. I could use a test enclosure with adjustable and removable details to examine things.
For my personal toy, I'd like a really good and fun "K10" which can punch at live levels, sound clear without obvious artifacts plus make reasonably good graphs. That may be doable with a higher aspect - or certainly with a small stub at the cabinet's top to smooth response and trap some reflections. An internal K-tube would keep things tidy. I get the idea that Beta10cx would be a difficult thing to coax really good sound from - at least in a K. Michael Chua worked with quite a bit with crossovers to get acceptable vocals. BEta10C with Eminence's suggested CX xover values sounded very dreary and dull in my Karlsonator 12. 12LTA was ok but I will never love that thing unless Eminence slaps another pound of ferrite onto its back. I wish Fostex made a 10" version of 206 - do you think such a thing would be doable? - it would not take a lot to beat an AN10 standard.
A K12 might sometimes be the best compromise for a 10 inch speaker. I've got a beat-up old homemade Karlsonette with port moved to K15 position, and with Kappa12A and K-tube on top, it sounds more powerful and immediate than my Klipschorn with a cut by the late and great Rudy Rosa.
For my personal toy, I'd like a really good and fun "K10" which can punch at live levels, sound clear without obvious artifacts plus make reasonably good graphs. That may be doable with a higher aspect - or certainly with a small stub at the cabinet's top to smooth response and trap some reflections. An internal K-tube would keep things tidy. I get the idea that Beta10cx would be a difficult thing to coax really good sound from - at least in a K. Michael Chua worked with quite a bit with crossovers to get acceptable vocals. BEta10C with Eminence's suggested CX xover values sounded very dreary and dull in my Karlsonator 12. 12LTA was ok but I will never love that thing unless Eminence slaps another pound of ferrite onto its back. I wish Fostex made a 10" version of 206 - do you think such a thing would be doable? - it would not take a lot to beat an AN10 standard.
A K12 might sometimes be the best compromise for a 10 inch speaker. I've got a beat-up old homemade Karlsonette with port moved to K15 position, and with Kappa12A and K-tube on top, it sounds more powerful and immediate than my Klipschorn with a cut by the late and great Rudy Rosa.
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Carl is going on 80 years of age - perhaps his son Wayne would have ideas.
Here's an extended length version of an X15 aluminum K-tube by Carl vs a plastic tube with short stub by me. The Karlson tube had a "pre-wave" guide piece in it.
You could PM me and I'll give you Carl's contact info. FWIW, he's not answered my emails for a long time.
Here's an extended length version of an X15 aluminum K-tube by Carl vs a plastic tube with short stub by me. The Karlson tube had a "pre-wave" guide piece in it.
You could PM me and I'll give you Carl's contact info. FWIW, he's not answered my emails for a long time.
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