I think you've gotten the answers to that already, but just to elaborate:
The dotted line in the center divider shows a simplified/easier construction option for the center divider. Since you are CNC equipped, go for the solid line... Smoother expansion and the center divider will be stiffer.
Though it may be worth playing around with, I'd recommend the 'standard' 39" radius K-aperture. The dotted lines show an experimenters' option. It think it would be too laid back with the FE167.
I'm looking forward to seeing this build!
BTW, years ago, Gregg Baker (eeehaah) had a prototype CNC'ed Karlson made. He was hoping to offer it as a flat pak kit, but there wasn't any demand at the time.
Must be nice to have your own CNC
Looking forward to this build and your listening impressions.
I'd like to try this with the coaxial CD, but I'm not sure how to go about increasing the top channel by 1.3x. Raise the roof or lower the inside bit?
Thanks
If you lower the inside a bit, that is least disruptive to everything else and should work well. Are you going to try the Beta 10CX?
I'll certainly consider cutting some of these for the folks here. Let me take a step back and 3D model the K-6 in Sketchup to be sure I don't miss anything. I've done this before with other items I have built and then I know all fits once I get done machining the parts.
Once the K-6 is done, I can do the K-8 and K-12 also. Mods to these (especially width) would be easy...
So in the next few days when I get a chance I'll do a 3D sketchup with exploded parts of the K-6... and post it here.
A Beta 10CX should be used in a full size Karlsonator (15 in). It will work in a 10/15 scaled one but at the expense of bass extension. Although you gain some efficiency. These sims are with a wall far away so you are not getting the added bass extension from a back wall.
Full Size
10/12 Scale
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F10 `50Hz for the 10/12 Karlsonator seems an acceptable tradeoff - how about Beta 10CX versus Kappa 12A in GB's Karlsonator 12? - a pair of Karlsonator 8s should be nice too - dunno if the stock Karlsonator8 would match a Tangband 1772 - ? (also have Beta8cx and Nirvana stamped frame Super 8s) FE206EN had the most punch/attack for an 8" FR in a regular Karlson K12. Beta 10cx is a good high-value driver.
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Yes. Beta 10CX w/ Selenium DT220Ti and the 2k5 crossover. Is the "full sized version" the "Karlsonator" from post #1?
Karlsonator 6 3D sketchup model done. Note "discontinuities" circled in red. Those are because I can't undercut on the CNC nor do I want to (although it can be done carefully) flip the piece to machine it from the other side. I could manually (gasp) sand off the protruding part I guess...
Next step, lay out the pieces in 2D for cutting. Also cut holes for speaker and terminal as well as drill mounting holes for those also. I *hate* having to cut holes after-the-fact.
Next step, lay out the pieces in 2D for cutting. Also cut holes for speaker and terminal as well as drill mounting holes for those also. I *hate* having to cut holes after-the-fact.
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You could try a small hand plane (if you have one) or even a rasp/file for faster removal of edges such as that.
btw - the picture in the link below is one of Carl's test K's - I think as its assembled, its 28"H x 13.5"W x 11 7/8" deep. All parts remove so it can be flat packed. At this size it functions well as a K10 and its vent is a full width slot above the elliptical reflector. Carl is an engineer who did early FEA work - says it would take a lot of code to describe a Karlson. There's modern microwave work which can be applied. For one like myself, its empirical with guesstimates.
Karlson enclosures in general give a better presentation for their size than horn and direct radiator. Its amazing that few give them serious consideration. XRK971's akabak recent investigations should give general directions.
it would be good to get a feel from akabak of the impact of cavity aspect - such as comparing GB's "Karlsonator" forward's cant reflector vs one which initially tilts backwards such as Ken Lehman's 8 inch K-coupler experiment. (KenL's cabinet had the feature of adding an extra chamber to the K-coupler section)
testbox by Carl
http://imageshack.us/a/img844/6743/hak8.jpg
KenL's basic 8K
one of my XT8 - essentially a tall K8 and about the size of Carl's coupler but the upper board is canted forwards like the Karlsonator
Karlson enclosures in general give a better presentation for their size than horn and direct radiator. Its amazing that few give them serious consideration. XRK971's akabak recent investigations should give general directions.
it would be good to get a feel from akabak of the impact of cavity aspect - such as comparing GB's "Karlsonator" forward's cant reflector vs one which initially tilts backwards such as Ken Lehman's 8 inch K-coupler experiment. (KenL's cabinet had the feature of adding an extra chamber to the K-coupler section)
testbox by Carl
http://imageshack.us/a/img844/6743/hak8.jpg
KenL's basic 8K
An externally hosted image should be here but it was not working when we last tested it.
one of my XT8 - essentially a tall K8 and about the size of Carl's coupler but the upper board is canted forwards like the Karlsonator
An externally hosted image should be here but it was not working when we last tested it.
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XRK971 can give an educated guess based upon aKaBak - a firend who built a rough Kalrsonator 8/XK8 form factor, preferred the Karlsonator 8 configuration to the XK8 venting.
All K12 from 1954 to Karlson's death in Jan. 1973 had the same outside dimensions and seem suitable for FE206EN. The Karlsonette/K12 probably would exhibit more "hit" (output in the 110Hz to 220Hz octave) than a Karlsonator 8. I measured 2dB to 5dB more output in that octave from the Karlsonette than my XK8 using the Tangband W8-1772.
FWIW, I liked FE206EN better than Tangband's W8-1772 when each was mounted in the Karlsonette. I did not run FE206EN in my XK8
long enough to form a solid impression.
W8-1772 sounded better in a K-coupler smaller than K12 than in the Karlsonette (1954 K12).
the "Karlsonator" was suggested for 12" drivers and seems rather large for an 8" driver.
below is a comparison of the XK8 full width vent tuning versus the Karlsonator 8 venting in the same box
- you can see the TQW venting tunes lower for similar vent arear. In practice, I had to truncate XK8's vent area.
John Lapaire's impedance plots - John's prototype was a bit smaller in depth than the official Karlsonator 8
the xk8/Karlsonator 8 prototype got pretty good marks with FE206EN
All K12 from 1954 to Karlson's death in Jan. 1973 had the same outside dimensions and seem suitable for FE206EN. The Karlsonette/K12 probably would exhibit more "hit" (output in the 110Hz to 220Hz octave) than a Karlsonator 8. I measured 2dB to 5dB more output in that octave from the Karlsonette than my XK8 using the Tangband W8-1772.
FWIW, I liked FE206EN better than Tangband's W8-1772 when each was mounted in the Karlsonette. I did not run FE206EN in my XK8
long enough to form a solid impression.
W8-1772 sounded better in a K-coupler smaller than K12 than in the Karlsonette (1954 K12).
the "Karlsonator" was suggested for 12" drivers and seems rather large for an 8" driver.
below is a comparison of the XK8 full width vent tuning versus the Karlsonator 8 venting in the same box
- you can see the TQW venting tunes lower for similar vent arear. In practice, I had to truncate XK8's vent area.
John Lapaire's impedance plots - John's prototype was a bit smaller in depth than the official Karlsonator 8
An externally hosted image should be here but it was not working when we last tested it.
the xk8/Karlsonator 8 prototype got pretty good marks with FE206EN
An externally hosted image should be here but it was not working when we last tested it.
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