These designs are fascinating. Just from looking at them, I would think that the mids and especially the highs must sound muffled, radiating from behind that partially open baffle board.
Not at all. Very nice, especially with the faital pro drivers. The whole response sounds fantastic, and other than increasing bass response and dispersion, running without the front baffle makes no other real discernible differences really.
I've been actively interested in audio since the early 70's, yet, somehow, managed to not have heard of the Karlsons.
So, I've been doing alot of reading up on Karlson's designs, and have a question you might be able to address.I'm curious as to whether you've experimented with driver mounting position within the coupler mouth? In other words, is there any significant difference in the sound due to the position of the driver relative to the tapered slot flare? For example, with your tandem driver Karlsonators, have you listened with only the upper driver (the one located most directly behind the narrow portion of the coupler slot) powered, versus having only the lower driver powered? Is the sound character consistent? More specifically, I'm wondering whether the highs remain equally present and dispersed from the driver located directly behind the narrow slot?
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I haven't, but you might want to ask xrk971, he's built a whole herd of them over the last few years
Okay, thanks for the suggestion.
John E. Karlson's famous 15 inch enclosure had its testing in the summer of 1951 and commercial debut, the fall of 1952 at The Hotel New Yorker hi-fi show. The 12 inch model was introduced in the fall of 1954 -i think the eight inch model came in 1955. There was a Karlson 18 inch speaker model shown in on brochure. The 15 inch model, loaded with Electro-Voice 15TRX, provided sound for many of the 1964-65 World's Fair exhibits. Karlson also made a line of "asymmetric" projector speakers and those were also branded and sold by his friend Jess Oliver. Those ranged in size from the little Karlson "Rocket" (KR-5) to the 15 inch Altec loaded AP100 / Oliver "Magna-Clam".
Karlson's Open Ended Waveguide patent was concurrent with the release of his "X15" 2-way speaker of about 4.5 cubic foot external bulk which employed a 41Hz fs CTS 15 inch speaker and first, a mini-asymmetric projector tweeter made of plywood and driven by a 3 inch cone speaker. That was replaced by a slotted tube tweeter with compression driver.
with the right speaker, a Karlson cabinet sounds quite natural and they
often good substitute for horn systems.
The Karlsonator variant comes from Diyaudio member GregB. I have Karlsonator12s and a little foam core set.
although I've been an audio "purist" at times I very much like spatial enhancers, dynamic expanders and the Aphex aural exciter and find they are worthwhile with a lot of classic rock cds and homemade tapes.
a K-tube tweeter can sound very good in its range. For a one inch compression driver, tape a 1" diameter pipe about 5.5" long. Start the slot at 1/8" gap using a half ellipse template. A quick POC tweeter can be made by rolling up paper and cutting the slot with scissors.
Karlson's Open Ended Waveguide patent was concurrent with the release of his "X15" 2-way speaker of about 4.5 cubic foot external bulk which employed a 41Hz fs CTS 15 inch speaker and first, a mini-asymmetric projector tweeter made of plywood and driven by a 3 inch cone speaker. That was replaced by a slotted tube tweeter with compression driver.
with the right speaker, a Karlson cabinet sounds quite natural and they
often good substitute for horn systems.
The Karlsonator variant comes from Diyaudio member GregB. I have Karlsonator12s and a little foam core set.
although I've been an audio "purist" at times I very much like spatial enhancers, dynamic expanders and the Aphex aural exciter and find they are worthwhile with a lot of classic rock cds and homemade tapes.
a K-tube tweeter can sound very good in its range. For a one inch compression driver, tape a 1" diameter pipe about 5.5" long. Start the slot at 1/8" gap using a half ellipse template. A quick POC tweeter can be made by rolling up paper and cutting the slot with scissors.
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freddi, thanks, for your very informative post. I've read online some of Karlson's papers from the 50's or 60's about his unique acoustic coupler design. It's advantages appear so compelling that I wonder why it has remained relatively obscure since then. I can only think that maybe the application falls short of the theory? Perhaps, you might be able to shed light on why the evident commercial failure of the design occured. What are the practical drawbacks as you see them?
Also, perhaps, you know the answer to the question I asked a few posts back. In the box 8", 12", 15" etc. Karlson designs, the driver is positioned within the flared slot of the k-coupler. This leads me to wonder whether the driver front is actually coupled to the k-coupler in these designs. In other words, is the driver's high-frequency dispersion actually significantly broadened by the slot located rather openly in front of it?
Thanks, again.
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