Karlson resonator -how do they work?

Karlson resonator are a very controversial old type and I don't have much other than funky graphs, some observations and impressions - some favorable - some not.  due to diffusion/ "whatever", upper highs may be less loud than direct radiator.

initial slot gap seems to affect midrnage and highs and a frined graphs this with mic on floor/

subjectively with certain motors, cone motion on strong transients seems reduced  (K15 is excellent rap box)- this observation is somewhat complicated in some smaller original models which only had ~30-33 cubic inches rear chamber per square inch cone of cone area giving high cutoff and tight rear chamber air-spring for starters.

K could be looked at as a tone chamber device - its inventor described them in 1950 as having "controlled reverbration" and impedance tranformation

maybe when done right, they live up to some original claims including reduced Doppler distortion.

one dude who built K-couplers had the following views and noted distortion in a B36 size diy coupler:

Dave Young - snippet:

"-As a low frequency cabinet, the Karlson is usable to 35hz with
low harmonic distortion. Like any enclosure that depends on porting to augment the bass output, Theile-Small parameters have
to be taken into consideration. I have yet to measure anything of
comparitive size that came close. They get ugly above 175 hz. and require a crossover set from 100-150 hz. The key to its low freq.
performance is the coupled front chamber. The increased air pressure loads the cone and dampens it.

A front loaded woofer and a horn loaded woofer operating below cutoff doesn't have that advantage.

Twice I've measured the 3rd harmonic of 40hz(120 hz) louder than the fundamental with 100 watts feeding the speaker.

The Peavey FH-1 and a Yorkville 2-18 with RCF's. When the 1504-4
Black Widow was tested in a 12 cu. ft. Karlson, the 3rd harmonic
distortion went from 103% to 8%. I didn't have the Yorkville long
enough to switch speakers."
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assuming K's really "work" - how does the front slotted wedge provide damping of cone overshoot?  - are there HF & beat-tone components in cone overshoot?

tonight I'm running a Beyma 12cX in a 4.3cu.ft. coupler with ~2cu.ft. rear chamber and 1cu.ft. front  - on Shelley Manne's drums solos the pyschoacoustic effect is one of  good transients with maybe 1mm peak to peak on kickdrum.

maybe its all just an illusion/ FR - balance thing?

Contour used K15 with Beyma 15 and Craaft 18  - perhaps he has a few thoughts at this point.

Freddy

not quite the same thing - got ~3M t-lines  for 10" driver - OK for wimpy home subs if highpassed as some  cds must have 8Hz content of osme sort. 

Karlson at LF corner generaly don't go lower than rellew equal to rear chamber - cone seems to move less (might be moot in home use)-

since some of their sound may be energy storage and difference between sounds emanating from a choked cavity vs flat front box where things wrap around cabinet sides sooner

K's R fun (if you like em) with rock and rap -my double 15" JBLL's sit

original 1951 model used a shelf up front which pushed a null higher, acts as bondary for port and in rear, a cnoke/lowpass.

had a shelfless K play pretty nice with Ozzy's early recordings - by sticking board in - could emulate sound of original = konvertable haha

original K with good 15" coax sounds fab IMO with bowed bass - have run Altec 604 and big mo Eminence with serires and both are fun   - -stuff on top is bit tougher  do to driver separation and agnles in dispersion

the elusive Carl Neuser who builds/studies K's thinks they exhibit better dyanmics than horns - think his only horn reference in house with K are 4 S9 University  - I'd like to know how Saul White & Abraham Cohen's S9 would fare with something like 2220H  (S9 drawings aer over at loudspeakerguru  =Jeff Robinson)

I don't even know if K's "work"  -  kinda like questioning "God"  & ultmate purpose of mankind  

onto horns-

if can get throat section decent,  then a simple bassrhorn should rattle up to 500 to meet midhorn - Fitz may have advantage with DR/Orthophonic-revival (doesn't have hi-res graoh) but not sure as Bruce (Edgar) does OK with "old ways" and flat panels   - if lucky a single triangle with ramps placed in box with a few reflectors should be "bearable"   - maybe splaying sidewalls would help- straight horns are Ok but 100Hz trumcated to ~440 sq.in. mouth/80 sq.in. throat with back chamber  come in ~30 inches deep - half octave lower and get kick horn (hows that coming along folks?)

for home use Dr. Edgar seems to separate horn things at around 70-100hz to sub .- think this is partly to improve imaging - a 50-55hz  1/4 size horn is getting kinda bulky to place - my 1st horns  were k-horn copies. although by no means perfect and running woofer mush-motor,  clones were head turner in little room with spankling new chrome Dyna MKIII's   - still got one real K-horn bass section buried in mess.