Karlson/Klam directivity question

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Sodacose

Sodacose

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Joined 2006
#1
Has anyone ever tried listening to a Karlson on its back, so that the lens is oriented in roughly the way a Klam would be (ie K aperture on top facing 'up')?

I'm wondering whether loading a small full range with a horizontal K aperture on 'top' of a speaker enclosure is something worth experimenting with. In essence, a small Klam built into the top of a woofer box that can handle everything 150-200hz and under. Based on what I can find on K apertures, the directivity might work if the speaker is kept below ear level.

I ask because I have a unique WAF imposed situation. I can build whatever I want, but it cannot be taller than 26". Seems like a 2 cuft bass box with a Klam has some merit. I'm thinking the outside dimensions could be rectangular with the inner Klam partition oriented so that the top/lens remains parallel to the floor and perpendicular to the sides. Could be a very aesthetically unimposing design.

edit: Also I'm using SETs for amplification, so looking for high sensitivity ideas. And I suppose I could just build a K12, but I want to explore other options as well.
 
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#3
I'm not really considering a Karlson on its back per se, but just how the lens affects directivity. More like a small Klam on top of a bass bin.

I have been looking at all the Karlson designs a lot. Think I might have caught the bug. The Karlsonators all seemed more than 26" high though? The 8 is something like 28", isn't it?
 
#6
Freddi-

Glad you're chiming in. Every time I google Karlson one of your projects pops up.

That second glamor shot with the model is kind of what I have in mind insofar as the orientation of the K aperture. Though the driver would be firing up and out, away from the wall. Not really a Karlson in the bandpass loading sense so much as using the Karlson slot to aid the dispersion of the FR driver (which would be angled up at probably 30-45 degrees).
 
#7
you could also investigate a simple slot aperture and the old dog-bone variant which appears in JBL's Eon

An externally hosted image should be here but it was not working when we last tested it.

JBL_EON_600_610_612_615_speakers_nieuws2.jpg
 
#8
It might be hard to make a Klam sound uncolored. I think you'd be better off with a K-tube and a compression driver on top of your bass box. I've used a PSD 2002 and 7.5x1" tube for this, and it sounds open like a very good dome tweeter but with horn-like dynamics. Crossover was 1200hz 3rd HP/2nd LP, IIRC. Any number of 8", 10" or 12" drivers can play nice that high with no problem at all. An open framework covered with grill cloth should give it good WAF.

Some of these newfangled aluminum drivers can play very cleanly and karlson like even in a simple BR, but maybe something like x's XKi could also be considered.

Or, a simple reflex box with a modernized BBC slot like the JBL freddyi mentioned is a good idea too.
 
#10
A very straight forward way to get better directivity on a fullrange is just to put a simple multicell horn in front of it. Three cells should be enough. Make it out of EVA or cardboard etc.
You don't need top or bottom on it so a reflector might be a better term than horn. But you will still get three (or more) lobes though.

I've never seen a real directivity measurement for the karlson slot (where it matters 5k to 15k).
 
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#11
Squeak said:
A very straight forward way to get better directivity on a fullrange is just to put a simple multicell horn in front of it. Three cells should be enough. Make it out of EVA or cardboard etc.
You don't need top or bottom on it so a reflector might be a better term than horn. But you will still get three (or more) lobes though.

I've never seen a real directivity measurement for the karlson slot (where it matters 5k to 15k).
Click to expand...

A K aperture has a great impact on directivity. This is an XKi for a 4in driver.

461843d1422331652-xki-xs-ab-initio-karlson-6th-order-bandpass-xki-rs100-4-tape-neweq-polar.png
 
#15
By the sketch in post #4, I'd suggest using the Karlson to load the MB unit, instead of HF. Wide and uniform directivity is a strength of Karlson, no doubt. However, subjectively, I feel its MB punch is more charming.

If WAF is a major issue and the cabinet needs to be low (and placed close to the wall), then just make the HF unit up firing. You'll get almost omni, maybe after some helps of EQ...
 
#16
CLS said:
By the sketch in post #4, I'd suggest using the Karlson to load the MB unit, instead of HF. Wide and uniform directivity is a strength of Karlson, no doubt. However, subjectively, I feel its MB punch is more charming.

If WAF is a major issue and the cabinet needs to be low (and placed close to the wall), then just make the HF unit up firing. You'll get almost omni, maybe after some helps of EQ...
Click to expand...

Thanks, CLS. I have been reading a bit on the floor coupled up-firing threads about this as well. That may be an option.

I'd like to try one of the newer Dayton point source drivers and I think they might work well for that kind of arrangement with the rising response and off-axis performance (and for the same reasons I *think* they lend themselves to Karlson enclosures). So it is kind of between:

PS220 in a traditional Karlson/Karsonator
PS180 in a fast-style arrangement, possibly upfiring
PS95, maybe mini Klam style, maybe upfiring, definitely needs help with LF

I'm unsure of the last one because all of my amplification is 5-8W SET (either RH84, SSE, or 6AV5 SET) and PS95 may not have the efficiency.

Freddi, your question is kind of the crux of the issue. Is there a beneficial way of loading a small FR or tweeter with a Karlson aperture to improve directivity in the HFs? Seems like the Karlson Rocket was designed with this in mind, wasn't it?
 
#17
re: ps220 in the 1954 Karlsonette/K12 - here's one impression http://www.diyaudio.com/forums/full-range/191302-dayton-8-fr-ps220-discussion-10.html#post2684506

a Karlsonator8 might be smoother

the klam arrangement with the driver relatively far away may limit horizontal dispersion more than a lens or k-aperture that is closer to the driver - may depend on the angle - i have klam15 and klam12 which are 'nice sounding' -

klam15 with an extended k-tube crammed down the coax's throat
https://www.youtube.com/watch?v=mupb8X6iZ6I

2.5" wide at bottom K-cavity
6LAHuXT.jpg

086oLHT.jpg
 
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#18
the original KR5 Karlson rocket driver did not go very high - i think Carl Neuser used a 5" Polk coax in his little Rocket version below - a K-tube can be used to extend the coax tweeter

I think the taper angles would be 6 and 12 degrees

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


DiyVladimir's PS220 cabinet - Karlson's 1954 K12 aka "Karlsonette"
237044d1314188053-dayton-8-fr-ps220-discussion-k3.jpg
 
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#19
Good to hear the PS220 worked well in a K12. Maybe the larger size with more breathing room helps. I designed a smaller 0.43x scale K15 for it to work above 100Hz with a sub below and the sound was not good. Perhaps something to do with how there is whizzer and how it is influenced by all the air rushing by through the K-aperture. We switched to B&C coaxial and it was much better. The small K cabinet exhibited extreme cone control that allowed some very high SPL's without hitting cone excursion limits. Very few cabinets can control a cone better than a K. It is certainy better than a sealed cabinet.
 
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