that looks quite good and not too far off from what John Karlson published in the January 1954 Radio & Television News Karlson speaker article with the 4.5" wide by 9 inch tall port.
That was a cool issue as also had Bob Moog's Theremin article.
https://www.americanradiohistory.com/Archive-Radio-News/50s/Radio-News-1954-01.pdf
Note Karlson warned against directly scaling K15 by 0.8 to get a 12 inch cabinet. In the fall of 1954 the first K12 (aka "Karlsonette") made its debut and the front shelf feature deleted. IMO its ok to scale K15 and its port. That shelf may segregate some highs from the upper front chamber area.
That was a cool issue as also had Bob Moog's Theremin article.
https://www.americanradiohistory.com/Archive-Radio-News/50s/Radio-News-1954-01.pdf
Note Karlson warned against directly scaling K15 by 0.8 to get a 12 inch cabinet. In the fall of 1954 the first K12 (aka "Karlsonette") made its debut and the front shelf feature deleted. IMO its ok to scale K15 and its port. That shelf may segregate some highs from the upper front chamber area.
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That is good to hear! It is a pity I do not have two cabinets. I will play around with it in mono. I am really interested into its polar measurements. If there will be another nice and sunny weekend soon, I'll take it out and measure.
regarding one speaker, you could do like I often do and play one channel at the time - that can be quite dramatic with recordings from the days when things were either centered, or fully panned to left or right 😀
or sum via resistors (EDCOR makes a little transformer summing box so there may be similar in your parts)
or sum via resistors (EDCOR makes a little transformer summing box so there may be similar in your parts)
let us not forget - the Karlson enclosure did a lot of hit records
- Owen Bradley in his earlier Quonset Hut studio.
K15 was used in 3-channel control room and other parts
- Owen Bradley in his earlier Quonset Hut studio.
K15 was used in 3-channel control room and other parts
I moved the K15 to the main room, on top of it there is now the UICW box to try the UICW with a Karlson as the (mid)bass unit. And a variety of K-Tubes to be tried as well, including the ones inside the mid horn. Sadly, no time for measurements or listening.
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Hi pelanj, when you eventually get time, would you check your K15's front chamber depth and driver cutout position against the official Karlson plan published in January 1954?
apparently whomever operated mixing console was sitting down - the coaxial's high frequency lobe could be pretty much on center axis and K15's baffle tilt is ~30 degrees
Well, I have to admit that I had never seen or imagined it....
You always learn something new, thanks freddi 🙂
Finally I will try the Karlson outdoors - next month at my birthday party as a "subwoofer". The "satellites" will be my 90l Fane 12-250TC closed boxes (their premiere was last year🙂 - but in smaller boxes).
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Happy Upcoming Birthday !
K15 hopefully will add some kick to your 12-250TC.
It might be interesting sometime to try an oval or that JBL shape
slot in front of the Fane FR.
K15 hopefully will add some kick to your 12-250TC.
It might be interesting sometime to try an oval or that JBL shape
slot in front of the Fane FR.
Thanks! And thanks for the suggestion - that might help with the narrowing dispersion - and maybe some balance could be found between dispersion and loss of HF. My large 3D printer is idle at the moment, so I could actually try to print one and fit it instead of the round protective grill I have there at the moment. Just scaling up the one I have for 8PE21 and making it round should work for the first test.
Unfortunately it does not fit the hot bed. Because it is round, it would have to be printed in four pieces. I am not sure I am brave enough to try :-/
cardboard and a steak knife would work - not pretty (maybe if painted flat blavk). Even an oval "lens" should be good.
Recovering from the party at the moment. The K15 clone worked really well with two coaxial Beymas both outside and inside. Played at low level not to annoy neighbors.