hey magnetar - any klam design thoughts?

freddi

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2005-08-16 4:21 pm
Karlson couplers and klam asymmetric projectors can be fun - but theres not a set of rules on design other than to look at originals (Metro has a K-woofer module)

maybe Magnetar has a few observations on picking klam baffle tilt, baffle size, etc. from building and tweaking several larger klams to share,

I've only used a 40 degree wedge and opened nose like Weiss's "Rocket" Karlson for KRC and Jess Oliver used a longer nose with 25 degrees wedge.

MIke's "Roise" klam seemed to be a good performer and kept the front length reasonable.

Freddy
 

freddi

Member
Paid Member
2005-08-16 4:21 pm
hey Moray - - I don't have any foam - maybe Mike can try it - imo Transylvania's k-tube is already near-perfeKt and a very good waveguide.

since U've built so many regular couplers, this thread could use some design rules input from you. I could never quite figure out the size and angle constraints of a coupler's visible volume vs the load or tuning it can do.

I hope you post a thread on the guitar coupler

Freddy

ps one thing I forgot to mention which needs investigation is the sonic effects of the first half of a coupler's flare - a small change in gap will not show on RTA but can make a huge difference in tone - -some couplers (not all) might benefit from larger starting gaps and playing with the first few inches of flare and this would be one means of tuning them to specific application or wants.

CN seems to think lower Xover can allow larger starting gap than using coaxial.

I had one little 18" coupler with 1.2" gap and it sounded great - large gap helped my 18" klam when running 2-way. As the slot is the real external port, system Fb tends to rise as gap is opened.

x15's 3-panel curved reflector made worse ground-plane graphs than a 10 degree slant board. a perpendicular board as in K15 and the first k12 may be pretty good for some regular Karlson type. Front shelf may be useful too. Rear shelf chokes can help.
 
freddi said:
Karlson couplers and klam asymmetric projectors can be fun - but theres not a set of rules on design other than to look at originals (Metro has a K-woofer module)

maybe Magnetar has a few observations on picking klam baffle tilt, baffle size, etc. from building and tweaking several larger klams to share,

I've only used a 40 degree wedge and opened nose like Weiss's "Rocket" Karlson for KRC and Jess Oliver used a longer nose with 25 degrees wedge.

MIke's "Roise" klam seemed to be a good performer and kept the front length reasonable.

Freddy


I only built the Rosie as far as sealed Klams go - others were open not reflex. 'Rosie' is still around but tough to get out of the room seeing the cabinets are like 160 lbs a apiece - A whole lotta Rosie

Foam in the tube is like foam in a horn. A big waste of sensitivity.
 
Hey Mike...

no argument regarding foam and loss of sensitivity. That said a k-Tube ought to be as close to ideal in terms of lauching planar waves (at the throat) and keeping that wave planar along the tube. As far as I understand it that should account for as low as it gets HOM's. There in lies my interest. Should stuffing the tube with appriciate open cell foam result in better sound (putting aside sensitivity issue) then that would be saying a lot about the impact of HOM's. Of course if you could not hear any difference it might just mean that the tube was so free of HOM's that the foam made no noticable difference at all. In any event stuffing a small ID tube is as easy an experiment as it gets so what the heck?
 
Re: Hey Mike...

moray james said:
no argument regarding foam and loss of sensitivity. That said a k-Tube ought to be as close to ideal in terms of lauching planar waves (at the throat) and keeping that wave planar along the tube. As far as I understand it that should account for as low as it gets HOM's. There in lies my interest. Should stuffing the tube with appriciate open cell foam result in better sound (putting aside sensitivity issue) then that would be saying a lot about the impact of HOM's. Of course if you could not hear any difference it might just mean that the tube was so free of HOM's that the foam made no noticable difference at all. In any event stuffing a small ID tube is as easy an experiment as it gets so what the heck?

I jumped to a conclusion making that statement without even trying it- let me actually try it with the tube - please give me a couple days - we all know it will kill some of the output but what else will the foam do? (subjective listen and a fast measurement should indicate something)
Cheers,
Mike
 

freddi

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Paid Member
2005-08-16 4:21 pm
hey Magnetar - one thing we don't fully know is how much we can squeeze a Karlson's front chamber and still get some useful coupled-cavity and spring action --I want to say they don't work but experience says dynamically, Karlson couplers can do well subjectively compared to reflex or some horn.

Karlson wanted a reverb effect and that alone affects the perception of highs saying coming off a coax tweeter. In normal coupler I think the upper half of the device and its aperture in that region affect tonality and some (but not every) couplers/speaker combos might work best with larger gap

Karlson on a good day might be nonsense devices that work well - or "accepted" technology doesn't work (and sound) as well as some scientists might wish to think.

whats your opinion of the Transylvania K-tubes? - still wanna given them to me ? LOL - -I would not part with mine and years previous to those used 1" ID pvc tubes and thought those were fun.

got any ideas on midbass couplers??? - how about a portable K-boombox?

Fred
 

SamL

Member
2004-06-11 4:47 am
Wgtn
Hi Freddi,

Is there a web site about Karlson speaker and its various design? It look very much like an art. Well, I am a newbi in this with Magnetar pointed me to look at Karlson Klam. Doing a search and your name appear on almost all post with Karlson so I guess you are the best person to ask. Not quite sure where to start other than reading endless thread of discussion.

Thanks :D
 
freddi said:
how about a portable K-boombox?

I have been ponding the same for quite some time. The Karlson appeture design with it's ability to make the speaker audibly disappear would be a considerable benefit to my boombox, however I find it extremly difficult to work a design that is based so much on guess work, and also it's damn near impossible to shrink so much that it would fit my design specifications.

Has anyone tried making one where the appeture is divided into several smaller ones? I'm thinking that it might be possible to have an oversized grill (like a 12" grill for a 10" woofer) and cutting out 3 or 4 smaller appetures in the grill. With proper depth and angling behind it might be possible for that to work.
 

freddi

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Paid Member
2005-08-16 4:21 pm
Job Ulfman's "Karlson Speaker Project" site is still up but his forum quit in 2003
http://home.planet.nl/~ulfman/

Karlson's original designs and aspect are the reference with K15 being a logical start. (K15 seems liked by Cogent's designers) "Klam" refers to Karlson's asymmetric projector but the term sometimes used for any Karlson speaker.

a lot of the tonal control is probably in the first (starting) half of the aperture. John Karlson's K15,and K12 used radial arc wings.

Karlson's open-end waveguide HF is interesting - maybe Magnetar will give some impressions of how the Transylvania version sounds

one recent Karlson builder seems happy with Gauss 5181 K18 whihc is around 10 cubic foot external bulk.

John Karlson said they would not "work" without a hard coating in the front chamber which I interpret was needed to preserve a lively HF balance with coaxial and dual-cone speakers, Jess Oliver's Phase III vocal projector (Karlson's 10" klam) had a 0.060" sheet of plexiglass along its top plate.

I had a lot of posts with Karlson's patent references - a Goole patent search would find them quick.

theres some art involved in new couplers and it would be a good idea to have a test coupler with removable wings which can "swivel" on cleats to alter the gap and flare; adjustable area vent; adjustable rear lowpass choke. Moderately low Q seems to be a good idea.

*****************
re:Boombox - you'd basically treat the coupler like a bandpass box to see response - a coupler with 10" (beta 10cx) had a coupled cavivity peak around 210Hz - it needed work as that peak was a bit much for hifi - if the rear chamber had been tuned higher then perhaps the passband would been flatter (with less LF) - Metro truncated the aperture in their T15 and used a fold-back stub to gain the front chamber air-mass.

15" PHL woofer - metro T15
[IMGDEAD]http://img229.imageshack.us/img229/2277/ksub1cu5.gif[/IMGDEAD]

here's a Karlson 8 copy with 3-slit vent and a Sammi 8" with QTs ~0.38 in half space with mic on ground vs K12 with 80oz magnet 70Hz coax and a 15" Silver Iris coax - theres rise in ~ the 3rd Z peak region -- a stock K8 probaby has Fb around 85Hz or so.. Some of the "hit" and reberberatiion is controlled in the first few inches of slot. T15 might not have much of this effect (?) I could put a wad of polyfill in the K*'s first inch and change the impression of its tone.
[IMGDEAD]http://img129.imageshack.us/img129/8781/oldc12cxx15vsk12vsk8samyw8.gif[/IMGDEAD]

here's stuff I posted with impedance graphs
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=115688

Freddy
 
freddi said:
hey Magnetar - one thing we don't fully know is how much we can squeeze a Karlson's front chamber and still get some useful coupled-cavity and spring action --I want to say they don't work but experience says dynamically, Karlson couplers can do well subjectively compared to reflex or some horn.

Karlson wanted a reverb effect and that alone affects the perception of highs saying coming off a coax tweeter. In normal coupler I think the upper half of the device and its aperture in that region affect tonality and some (but not every) couplers/speaker combos might work best with larger gap

Karlson on a good day might be nonsense devices that work well - or "accepted" technology doesn't work (and sound) as well as some scientists might wish to think.

whats your opinion of the Transylvania K-tubes? - still wanna given them to me ? LOL - -I would not part with mine and years previous to those used 1" ID pvc tubes and thought those were fun.

got any ideas on midbass couplers??? - how about a portable K-boombox?

Fred


Fred - I like the tube lots = been listen to them since I got them. I need some time to copy them then they are yours.

I have a pair of PAS 2580CX coaxes here, how would those be in a K15?
 

freddi

Member
Paid Member
2005-08-16 4:21 pm
hey Mag - you should keep your tubes "forever - besides good they are rare audio history - my one pair is good for me - if you come up with a better tube let me know.

here's my x15 copy cut by JL topped with a 5.5" half-ellipse tube I made
[IMGHTTPDEAD]http://img410.imageshack.us/img410/4118/x15toe5.jpg[/IMGHTTPDEAD]

2580 coax - is that a 10"??? CN built x15 size and used martin 1844/15269 - good woofer but a lot of inductance at 4mH. CN's x15 20"W x 16"D x 28" high with 25 degree baffle, 10 degree middle board and a reflector at top to hold and angle a 9" inch tube down 30 degrees from horizontal - his coupler might play smoother than Karlson's with 3 panel ellipse approximation reflector. CN had a rear lowpass choke which is adjustable. The longer X15 style K-tube below measures rougher than Zintz's probably due to diameter transition(s) but sounds pretty darn good -- I think CN used a P=1,Q=1.7 opening which is faster in he second half of travel than the radial wings below - its good to have removable wings to set it for taste. Karlson's X15 had a 7.25"x1.875"ID tube mounted on the reflector panel and about 12 degrees down from horizontal so less HF was firing into the floor than CN's way

CN x15A coupler loaded w. K33E and 9"x1.875"ID tube
[IMGHTTPDEAD]http://img116.imageshack.us/img116/2730/x15a1lm.jpg[/IMGHTTPDEAD]

Zintz squeezed x15 even more assuming Acoustics 115BK was just like the KHYBOE (?) for hifi side vents might be better (I mean not having the middle portion of this 3x9 vent fire into the aperture as its a bit "wooly")

115BK EV15L outdoors -mic on ground I think - baffle angle = 20 degrees
[IMGHTTPDEAD]http://img529.imageshack.us/img529/334/ak6jpgep1.jpg[/IMGHTTPDEAD]


115 side view sans 1.5" lip
http://img490.imageshack.us/img490/5278/115bksidekp5.jpg
 

freddi

Member
Paid Member
2005-08-16 4:21 pm
one more thing Mag - that dude's custom KHYBOE topped with chromed "The Tube" looked real sharp - that might be fun with some good subs - maybe two tapped horn ~7 foot tall? - that oughta play a drumkit pretty well - to thse wings look radial? - is that about 0.75" starting gap?
[IMGDEAD]http://img214.imageshack.us/img214/8149/superk6lv.jpg[/IMGDEAD]

Leech Sound Lasers with "The Tube" and KHYBOE -- (btw -I've seen s sketch to two K-tubes firing into each other - its said thats the way Ted Nugent used them)

The mighty KHYBOE
soundl4.jpg


Leech Sound Lasers
http://home.planet.nl/~ulfman/images/soundl12.jpg
 

freddi

Member
Paid Member
2005-08-16 4:21 pm
it would probably sound good in stock k15 -- but if you were using a sub at 70-80 then x15 size or so might be fun - how about something about like a big k12 20"x30"x16" with 25 degree baffle, 10 degree port board (if angle is used) and a rear lowpass shelf adjacent to the bottom of a K15 style vent?

did U build only 1 12"K? - did it play pretty hard?
 
freddi said:
it would probably sound good in stock k15 -- but if you were using a sub at 70-80 then x15 size or so might be fun - how about something about like a big k12 20"x30"x16" with 25 degree baffle, 10 degree port board (if angle is used) and a rear lowpass shelf adjacent to the bottom of a K15 style vent?

did U build only 1 12"K? - did it play pretty hard?

That's right I did build a 12" K - It;s in the garage = forgot - I didn't really like it much loaded with the PHL 12.

I think I want to use the Koax in a regular 15 cabinet. Why would a big 12 be better? I'd like it to go to 45 HZ strong
 

freddi

Member
Paid Member
2005-08-16 4:21 pm
my apologies -- re:12" -- question was for my benefit as I'd like a different 12K for comparison to the originals (there were 3) - I've got two 12CX brands out of spec and Qts high on each pair.

you need a good size (like K15) 15K if no sub - -CN seems to think going taller helps - that might drop the 3rd Z peak and perhaps seesaw the response a bit (??) - -we can see Metro used a fold-back stub

impressions of tonal balance and reverb seems to depend on: baffle tilt, upper board tilt (if any), upper reflector type and cant, vent position, wings flare, starting gap - -sometimes a "protuberance" in the front is used as with K15 - just a small front shelf extension may alter balance - an dadjustable rear lowpass choke might help on kickdrum transients - -K15 had ~0.3sD - K12 had two boards to choke to 0.5 Sd

a perpendicular middle board might sound more "mellow" than one with 10 degrees forwards cant. K15's shelf partially offset a 250Hx dip and deflected some mids away from he upper half of the coupler.

besides T-S parameters, do you think baffle angle might affect the kick region's rampup?

what 15K scheme are you going to try? what makes sense? - theres been times when I really like K15

Freddy
 

freddi

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Paid Member
2005-08-16 4:21 pm
Magnetar's klams

hey Magnetar - what front chamber and rear chamber did you use for sealed 15" klams with field-coil 15"? Karlson's original klam/asymmetric projectors were vented probably for pressure release as rear chambers were small and this included the first "Rocket" with 4" CTS.

Rosie klam 1 & 2 had vented rear chambers? - -I believe you took the experiments further and would like for you to share some design rules and hints on getting a successful klam project.

after the holidays might you be game to expound a bit? - it was CN's notion that a longer front coupler will lower the cutoff. Alan Weiss wanted 40 degrees making his klam shorter than Karlson's originals and I did one 40 degree klam 18 with about 3 cubic foot rear chamber.

Hope you have a nice Christmas
Fred

ps - one thing missing = midrange couplers or mini klam optimized for mids