A Speaker that Kicks Butt in Large Spaces

FE206EN is great in K12 - think it will work well in the upcoming 0.65X K15. Here - it may sound pretty
good but have no low bass. I'm surprised as to how nicely it rear mounts.


1960's Karlson Eight/"K8" - they were produced from 1955 to Karlson's death and remained
the same size on the outside.
FyAVJCf.jpg


0.65 K15 awaiting clear coat from TheJessMan for Beta10cx and 8" fullrange
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two K8's a little eq on a Lepai cheap amp and a sub with the FE206en would be fun - - I love FE206EN in Ks :D - cohesive - lots of detail and energy - Karlson are the best way to play Johnny Cash. FE206EN in a K12 with "Get Rhythm" sounds very "live". K8's small rear chamber and high tuning would probably need the sub coming in close to 100Hz.

interesting - on the American Folk Blues Festival live '69 "Going Up And Down" with Earl Hooker, Mac Thompson's
bass has some deep sound and and kick drum can be felt. Maybe the 0.65 K will really kick hard (?)

I wish Fostex would make a 10 inch version of FE206EN - lol

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maybe an EV 15TRX coax - Stephens 206AX coax, Stromberg-Carlson RF-475 or Altec 604? - University? Carl N. said at one time, K15 were being used in some movie theaters. Compared to 1772 and AN8, I almost always prefer FE206EN for K-work.

there are a few recommended drivers in this plan excerpt from the January 1954 issue of Radio and Television
News K-article. There was a more extensive list in several of the Karlson brochures.

note the info on the plan image - it indicates Karlson was not happy with a 12/15 scaled K15 for 12"" - the 12 inch
Karlson which was a bit smaller than 12/15 and deleted the front shelf, made its debut in October of 1954 and was
nicknamed the "Karlsonette" - I think the eight inch bookshelf K8 came in around 1955.

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and it seems a lot of old Karlson were loaded with those classics = great bargains sometimes at thrift shops to get Jensen or Tannoy pairs valued in the thousands for $30. I have no mobility so get the non-bargains. A pair of empty K15 with asking price of $100 (often homemade K) can sit forever on Ebay. My first set is rough and needs a new shelf - might be the end of it to try to disassemble as I re-glued it pretty well long ago.

regarding LC1A - I heard that Hans Dietze said the Karlson enclosure gave better loading than Olson's cabinets.
 
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think these 0.65 scale K15 came out nicely sonically - I have one loaded with a stamped frame Nirvana Super 8. the other with the current Beta10cx and old APT50 - the coax with generic Eminence 3K5 network and no HF attenuation is smearing decays in comparison to the fullrange flattening out "depth" - but CX10's bass is quite good for such a little speaker and supports to around 60Hz - some crossover mucking and the coax should improve - fwiw an ADS1001S CD would probably sound pretty good even with the old 3K5 network (which usually really crossovers around 2K8)
 
sounds somewhat incoherent as Beta 1cx and the first series of APT50 are running the old Eminence 3K5 textbook value network - a more suitable network should improve things - a Breeze TPA3116 kicks it hard enough - its mate is currently loaded with he old stamped frame Nirvana Super 8. 15mm Baltic birch seems adequate for a little speaker (I think that's what RCA-Fan uses for most everything
 
hey XRK971 - the Karlson has been described as loading both sides of the cone - what does Akabak show for pressure distribution vs F in K15's front chamber, particularly from top to center to bottom of the cone? can those points be easily accessed in your model?
 
hi X - what happens in a K15 simulation in general if the front chamber is reduced in size to that of the X15? - X15 had around a one cubic foot chamber, a final aperture width of around 18" and aperture height of ~26.5"

the K-tube mounted internally works well - this was a reasonably close copy but my builder accidentally
raised the woofer cutout 7/8" from original spec. If I had a space or could drag outside, I would add rear chamber
and adjust its port to approximate K15's rear section.

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What is the reduction of the chamber volume? To first order using the XKi model for 6th order bandpass sub will tell you what happens easier than full model. Full model is not so easy to change volume of front chamber as it is tied to actual dimensions of 9 segments of front chamber as divided by imaginary lines. My guess is a smaller front chamber gives less bass extension and probably gives more cone motion control for higher ultimate SPL.