with regard to using two FF225WKs together in a Karlson, rather than having them side by side as Freddi drew, could they be mounted one behind the other in an enclosure sized more for a 15"or 18"speaker in depth but narrower, like the small karlson with the single FF225WH and how would you estimate the need volumes and therefore the height of the enclosure? If I recall correctly Moray James once did one with a transmission line behind the driver, vented at the top into the front enclosure.
jamikl
jamikl
Personally, I would limit low-frequency drivers to one per cabinet, aside from whimsical experimentation, especially for a fullrange driver. The SK8's general form-factor is pretty decent for FF225WK. If I were to do it again, I might give it a couple more inches in height and reduce front chamber volume by a few liters. I think I prefer the vent as it is, close to the driver. I'm still working on some tweaks on this box and will likely give the wings a round-over on both sides and add some bracing. A super-tweeter is definitely needed here and I've had luck with FT17H and even the old Foster phenolic-dome plastic horns. You can see these below with a small wooden "extension" bezel:
I've found that a larger vent area is better for the lower-midrange, as it minimizes the dips that are pretty much un-avoidable, but too long a vent will also cause problems at some point, yet you want to retain a sensible Fb. There are a lot of things to balance-out in the design of a Karlson. GregB, who mostly came up with the SK8 I believe, nailed a lot of things right off the bat.
IG
An externally hosted image should be here but it was not working when we last tested it.
I've found that a larger vent area is better for the lower-midrange, as it minimizes the dips that are pretty much un-avoidable, but too long a vent will also cause problems at some point, yet you want to retain a sensible Fb. There are a lot of things to balance-out in the design of a Karlson. GregB, who mostly came up with the SK8 I believe, nailed a lot of things right off the bat.
IG
Hello IG, nice to read you again. I am missing the K forum.
From what I noticed working on my XK4 all the above seem right, the X being taller, the front chamber not as deep, the wing closed at the top and down a bit and being more like a tractrix.
IG
I had a large vent, the HF were ringing, while reducing it progressively, the ring tone disappear, the bass get deeper but could get boxy if too closed.
Now all this is with an inside vertical separation parallel to the back side which is my own modification of the XK, it could be different without it.
BTW the XK4 have a good 100 hours now and are very enjoyable, they force me to listen, I just cannot do anything else while they play. They would certainly float the boat of 90% of music listeners. When I think I made them just like that without any particular care, to see what a Karlson was about.....
I know but I can't join, Owen was looking at the matter but don't know what's happen now.
hey Tooppy -- sure hope Owen can tell you how to get into Fullranger.com
SK8 came from a guesstimate of the smallest size coupler for an 8-inch driver which would sound good without help of a subwoofer. Carl made some "hints" which were vague and did not happen til Marinus made a HAK6.5 based on one of Carl's test-boxes. Greg B tied it together with his great drafting ability. John Lapaire was commissioned by me to make the prototype. IMO there can be a fair amount of leeway in sizing Karlson-type couplers vs the rather worthless bass reflex "alignments"
here's a Super 8 stamped frame fullrange in the little SK8 - I had to raise it off the floor as there was a distinct resonance if the cabinet sat directly on the floor. It sounded nice with W8-1772, FE206EN and BetsyK -- BetsyK tends to sound "dark"partly due to relatively high qts and Vas - that driver may prefer more rear chamber volume - but a helper tweeter could shift its balance.
hey IG81 - what can we do to move forwards on learning what works best in new Karlson type? The originals including K12 can musically beat my Klipschorns. (sorry PWK)
if this image looks "squat" - please click to enlarge it and get the correct aspect ratio.
SK8 came from a guesstimate of the smallest size coupler for an 8-inch driver which would sound good without help of a subwoofer. Carl made some "hints" which were vague and did not happen til Marinus made a HAK6.5 based on one of Carl's test-boxes. Greg B tied it together with his great drafting ability. John Lapaire was commissioned by me to make the prototype. IMO there can be a fair amount of leeway in sizing Karlson-type couplers vs the rather worthless bass reflex "alignments"
here's a Super 8 stamped frame fullrange in the little SK8 - I had to raise it off the floor as there was a distinct resonance if the cabinet sat directly on the floor. It sounded nice with W8-1772, FE206EN and BetsyK -- BetsyK tends to sound "dark"partly due to relatively high qts and Vas - that driver may prefer more rear chamber volume - but a helper tweeter could shift its balance.
hey IG81 - what can we do to move forwards on learning what works best in new Karlson type? The originals including K12 can musically beat my Klipschorns. (sorry PWK)
if this image looks "squat" - please click to enlarge it and get the correct aspect ratio.
An externally hosted image should be here but it was not working when we last tested it.
The standard radial K-slot does well overall. freddi's SK8 above with the more open slot should help relieve pressure and reduce apparent front chamber volume for drivers that don't require it. I suspect it might be a touch better for my FF225WK, but I've yet to try it. It does well with radial wings and does not exhibit peaking in its upper-bandwidth. One could go to the other extreme and do a tractrix slot as well.
IG
Freddi,
When you say expansions that emulate tractrix, do you mean mathematical expansions? If mathematical, the parabola is very close to a tractrix and for all intents and purposes of the accuracy or ability of someone cutting a profile in plywood and relative scale of soundwaves of interest. Also, a parabola (or even a circular arc) would be indistinguishable from a tractrix. For high freq horn design where wavlengths are smaller, the tractrix profile is more critical.
X
When you say expansions that emulate tractrix, do you mean mathematical expansions? If mathematical, the parabola is very close to a tractrix and for all intents and purposes of the accuracy or ability of someone cutting a profile in plywood and relative scale of soundwaves of interest. Also, a parabola (or even a circular arc) would be indistinguishable from a tractrix. For high freq horn design where wavlengths are smaller, the tractrix profile is more critical.
X
Hi,
What is the cross over freq to tweeter ?
Do you experience the sound is coming from the floor for such a low driver placement ?
- Elias
With either the above Foster plastic horn or the Fostex FT17H, I used around 1µF only and it worked well enough. As pictured, the SK8's were sitting on some random stuff to give a bit of elevation. Since then, I have put them on proper stands, which elevate them about 8", with a few degrees of back-tilt. The sound does not seem to come from down there too much this way and it helps prevent a bit of upper-bass over-emphasis.
I have also successfuly integrated small DIY 90° conical waveguides at ~3kHz, a mini Smith horn, also ~3kHz (see video link) and the Transylvania Power Company "The Tube" slotted waveguide, which does best overall, both sonically and conceptually!
http://www.youtube.com/watch?v=Wp0GRv3Kf28
IG
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some years ago KenL had a spreadsheet with tractrix-like K-apertures - I think the final expansion could be varied with a "60" or "90" (degrees?)
here's Ken's K-8 test coupler with an Eclipse W0838R polycone/rubber surround woofer - it went to 30Hz and had a front chamber profile as seen in some of CarlN's K-couplers. Look at its top -there was a removable plate and an extra downwardly tapered chamber could be added. That chamber made the coupler graph smoothly.
I tried a simple rectangular cross-section add on chamber with a "little" K18 which has only 80 liters rear chamber for its 18" woofer - that smoothed response
although that particular coupler was pretty smooth graph-wise from the beginning.
in a test box it should be easy to experiment with an added chamber -I would cant the inside board
cross section of my small K-18 to show the added chamber
here's Ken's K-8 test coupler with an Eclipse W0838R polycone/rubber surround woofer - it went to 30Hz and had a front chamber profile as seen in some of CarlN's K-couplers. Look at its top -there was a removable plate and an extra downwardly tapered chamber could be added. That chamber made the coupler graph smoothly.
An externally hosted image should be here but it was not working when we last tested it.
I tried a simple rectangular cross-section add on chamber with a "little" K18 which has only 80 liters rear chamber for its 18" woofer - that smoothed response
although that particular coupler was pretty smooth graph-wise from the beginning.
in a test box it should be easy to experiment with an added chamber -I would cant the inside board
cross section of my small K-18 to show the added chamber
An externally hosted image should be here but it was not working when we last tested it.
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Barely hanging on (to life
) it is heartwarming to have one of my creations being refered to. The HAK 6.5 is my favourite "small Karlson" and the "Dutch" 12" Karlson is my favourite large Karlson. I turn these on when I want to play Uriah Heap, Led Zeppelin etc. I like the K12 mounted upside down against the ceiling with a small gap above them and the HAK 6.5 sitting on a small stand, about 8" off the floor.For delicate vocal at (much) lower SPL levels I prefer the FF105WK and the FF125WK metronomes playing together where the 105's are facing the listener and the 125's are facing each other and standing just outside the 105's with the voicecoil aligned to the dome of the 105.
Best of both worlds.
Barely hanging on (to life
For delicate vocal at (much) lower SPL levels I prefer the FF105WK and the FF125WK metronomes playing together where the 105's are facing the listener and the 125's are facing each other and standing just outside the 105's with the voicecoil aligned to the dome of the 105.
Best of both worlds.
Hi there,
Hope you're doing alright! Here is a picture of said HAK6.5, if that's OK with you. It deserves to be seen!
It's the only one I have and not sure what happened to the rest, since the K-forum went down.
IG
I may have to put some factory K12 upside down just to make room for them. FWIW with better quality coaxial such as the large magnet cast frame 12" Eminence with inexpensive compression driver, sound quality overall is at least as good as a good 8" fullrange plus sensitivity and power handling are improved.
I follow the discusion on the Karlson cabinet with much interest.
In my younger days (1970..80) I was a big fan and after experiments with cabinets having speakers ranging from a small 2" to 15" I was amazed by the output it delivered.
I constructed a model consisting of two 12" cabinets, one on top of the other in such a way that the lower cabinet was set upside down and the other above as usual.
That way I created a sort of checkered opening made by the four wings of the two cabinets.
In the mean time I had a contract with a carpenter who could build them and I ordered a dozen.
The cabinets were equipped with the Philips ad12100 and others with RCF, type I forgot.
The horn was a piezzo and as filter a very simple cap.
No high tech; plenty of volume.
At that time I had a client who used several JBL cabinets, the type I do not remember. These were commonly used for sound reinforment at that time.
Disco was very popular in his bar and he managed to blow one.
So he needed a replacement unit until I had a new speaker.
I used my Double Karlson.
The karlson was a bit higher and slimmer and had the same power capability.
I mounted a smal horn tweeter in the narrow opening on the top.
Finally the replacement speaker came in (after 6 weeks) and I had a hard time to get my Karlson back as the sound was more defined and a lot louder. Price wise it cost about the same as the JBL's.
Later on (about 20 years) I heard from a diso owner who didn't know that I was responsible for these double karlsons, that he regrets to have them sold.
The sound was very loud and clear and that over a huge distance.
I therefore wonder if the checkered opening had something to do with that effect.
Any how, they stil sound good with a deep bass in my ears; but maybe I'm a bit over biased...
And as music is a personal issue, I like them.
In my younger days (1970..80) I was a big fan and after experiments with cabinets having speakers ranging from a small 2" to 15" I was amazed by the output it delivered.
I constructed a model consisting of two 12" cabinets, one on top of the other in such a way that the lower cabinet was set upside down and the other above as usual.
That way I created a sort of checkered opening made by the four wings of the two cabinets.
In the mean time I had a contract with a carpenter who could build them and I ordered a dozen.
The cabinets were equipped with the Philips ad12100 and others with RCF, type I forgot.
The horn was a piezzo and as filter a very simple cap.
No high tech; plenty of volume.
At that time I had a client who used several JBL cabinets, the type I do not remember. These were commonly used for sound reinforment at that time.
Disco was very popular in his bar and he managed to blow one.
So he needed a replacement unit until I had a new speaker.
I used my Double Karlson.
The karlson was a bit higher and slimmer and had the same power capability.
I mounted a smal horn tweeter in the narrow opening on the top.
Finally the replacement speaker came in (after 6 weeks) and I had a hard time to get my Karlson back as the sound was more defined and a lot louder. Price wise it cost about the same as the JBL's.
Later on (about 20 years) I heard from a diso owner who didn't know that I was responsible for these double karlsons, that he regrets to have them sold.
The sound was very loud and clear and that over a huge distance.
I therefore wonder if the checkered opening had something to do with that effect.
Any how, they stil sound good with a deep bass in my ears; but maybe I'm a bit over biased...
And as music is a personal issue, I like them.
Tarzan you have set me thinking, bet its not often that Tarzan did that!!!!
I have 4 x Fostex FF225wk. Now if I put them in four Karlson enclosures, with the bottom one each side upside down and the other two on top as you have suggested Then mounted a Fostex horn tweeter inside each upper one or on top if the the two boxes were not too high and perhaps ran them as 2.5 with the bottem boxes rolling off well before the upper boxes would it work?
I listen mainly to jazz of all types, 70s/80s rock and some from the mid/late sixties, a little classical and a little opera. Particularly like some thing with a bit of punch for drum solos and bass solos, but no boominess. The rock type music I listen to would be the likes of Pink Floyd, Santana, the Animals, Ten Years After, Bowls of Fire and some Joe Satriani.
jamikl
I have 4 x Fostex FF225wk. Now if I put them in four Karlson enclosures, with the bottom one each side upside down and the other two on top as you have suggested Then mounted a Fostex horn tweeter inside each upper one or on top if the the two boxes were not too high and perhaps ran them as 2.5 with the bottem boxes rolling off well before the upper boxes would it work?
I listen mainly to jazz of all types, 70s/80s rock and some from the mid/late sixties, a little classical and a little opera. Particularly like some thing with a bit of punch for drum solos and bass solos, but no boominess. The rock type music I listen to would be the likes of Pink Floyd, Santana, the Animals, Ten Years After, Bowls of Fire and some Joe Satriani.
jamikl
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