I'm interested in playing with a Karlson, K-15.
I do not however wish to go fullrange, or coaxial.
I'm curious to experiment with this either loved or maligned enclosure.
This has to be done on a strict budget, I can't afford to spend $500 on a single bass driver. My budget runs to more like $100 per bass driver.
Can someone help me with some T-S parameters suitable for this enclosure, so I can select a driver that is within my budget.
My plan is to combine the K-15 with a Horn Mid/High driver for a 2 way.
I am totally and completely open to encouragement, help, or constructive criticism. Naysayers will be cheerfully ignored. If, when I'm done, I don't like what I built, I'll recycle the drivers and barbeque the cabinets.
John
I do not however wish to go fullrange, or coaxial.
I'm curious to experiment with this either loved or maligned enclosure.
This has to be done on a strict budget, I can't afford to spend $500 on a single bass driver. My budget runs to more like $100 per bass driver.
Can someone help me with some T-S parameters suitable for this enclosure, so I can select a driver that is within my budget.
My plan is to combine the K-15 with a Horn Mid/High driver for a 2 way.
I am totally and completely open to encouragement, help, or constructive criticism. Naysayers will be cheerfully ignored. If, when I'm done, I don't like what I built, I'll recycle the drivers and barbeque the cabinets.
John
I am under the impression that with a Karlson, you don't need a whole lot of x-max but you need a woofer whose response doesn't "sag" in the bottom end like modern low-Q prosound woofers do. The old Altecs were good in that respect.
If this is true, then I think the Selenium WPU-1509 is a good candidate for a Karlson. In a 3 to 6 cubic foot box, with appropriate tuning, there's less than 1 dB sag (and no peak) in the bottom end - it holds up fine until it starts to roll off (no "shelving" or early rolloff).
Here are the parameters; try modelling in 3-6 cubic feet tuned 42-39 Hz:
Fs = 36 Hz
Qes = .35
Qms = 14.7(!)
Qts = .35
Vas = 164 liters
And, here's a link:
http://www.selenium.com.br/site2004/catalogo/pdf/pro_woofer_wpu1509-wpu1509-slf_new.pdf
Now from what I understand a Karlson doesn't behave like a conventional reflex enclosure, but looking at the behavior of the Altecs it looks like their low-end response followed this pattern. If anything, I think the Selenium might go a bit deeper than the Altecs, at the expense of a dB or two of efficiency.
I welcome comment or correction from those who know Karlsons better than I do.
Duke
If this is true, then I think the Selenium WPU-1509 is a good candidate for a Karlson. In a 3 to 6 cubic foot box, with appropriate tuning, there's less than 1 dB sag (and no peak) in the bottom end - it holds up fine until it starts to roll off (no "shelving" or early rolloff).
Here are the parameters; try modelling in 3-6 cubic feet tuned 42-39 Hz:
Fs = 36 Hz
Qes = .35
Qms = 14.7(!)
Qts = .35
Vas = 164 liters
And, here's a link:
http://www.selenium.com.br/site2004/catalogo/pdf/pro_woofer_wpu1509-wpu1509-slf_new.pdf
Now from what I understand a Karlson doesn't behave like a conventional reflex enclosure, but looking at the behavior of the Altecs it looks like their low-end response followed this pattern. If anything, I think the Selenium might go a bit deeper than the Altecs, at the expense of a dB or two of efficiency.
I welcome comment or correction from those who know Karlsons better than I do.
Duke
The two best drivers I have found for Karlson Klams is PHL 5320 and Altec 921-8a
Best person to ask is Freddi at The Karlson Forum.
Best person to ask is Freddi at The Karlson Forum.
Thanks for your reply's Duke, and Magnetar.
I looked for altec T-S Parameters for several hours yesterday, guess I should have looked on the "unofficial" site too...
Got Your E-mail Duke, responded, then decided to check you out. Nice webpages, excellent reviews on your products from several sources. aleveiated any doubts I may have had about the veracity of your offer.
Magnetar, I've seen freddi's pawprints all over the Karlson pages here. I hope that he will weigh in, as I would like to pick his brain too. I have in mind building them with inexpensive materials in a manner that will allow me to adjust the internal bits to experiment. then build a visually presentable cabinet when/if I'm satisfied with the sound.
I looked for altec T-S Parameters for several hours yesterday, guess I should have looked on the "unofficial" site too...
Got Your E-mail Duke, responded, then decided to check you out. Nice webpages, excellent reviews on your products from several sources. aleveiated any doubts I may have had about the veracity of your offer.
Magnetar, I've seen freddi's pawprints all over the Karlson pages here. I hope that he will weigh in, as I would like to pick his brain too. I have in mind building them with inexpensive materials in a manner that will allow me to adjust the internal bits to experiment. then build a visually presentable cabinet when/if I'm satisfied with the sound.
http://home.comcast.net/~jhidley/
Hi,
There is a very nice Jensen type 15" on the above link.
TBH with a horn for the top end midrange response becomes very
important, if you cannot measure then get a driver that is at least
specified to be flat in the midrange, many 15"ers are anything but.
Or easily controllable e.g. : http://eminence.com/pdf/delta-15b.pdf
Which is easier than : http://partsexpress.com/pdf/DC380-8_specsheet.pdf
Worst of course is if you have no idea of the response ....
/sreten.
Hi,
There is a very nice Jensen type 15" on the above link.
TBH with a horn for the top end midrange response becomes very
important, if you cannot measure then get a driver that is at least
specified to be flat in the midrange, many 15"ers are anything but.
Or easily controllable e.g. : http://eminence.com/pdf/delta-15b.pdf
Which is easier than : http://partsexpress.com/pdf/DC380-8_specsheet.pdf
Worst of course is if you have no idea of the response ....
/sreten.
Sreten, thank you for your reply.
It's been too wet for me to work today, so I've been reading all the material I could find on Karlson and his design. Looking for all available plans for the K-15. There were several minor changes made that I've been able to find up into the late 1960's.
I think that with any luck I'm making a deal with Duke at AudioKinesis to purchase a set of Seleniums that have pretty attractive parameters and a good response. They are certainly better looking than I had imagined being able to afford for the price.
I'm waiting for the moderator over at the Karlson forum to approve my membership and plan to post over there too.
John
It's been too wet for me to work today, so I've been reading all the material I could find on Karlson and his design. Looking for all available plans for the K-15. There were several minor changes made that I've been able to find up into the late 1960's.
I think that with any luck I'm making a deal with Duke at AudioKinesis to purchase a set of Seleniums that have pretty attractive parameters and a good response. They are certainly better looking than I had imagined being able to afford for the price.
I'm waiting for the moderator over at the Karlson forum to approve my membership and plan to post over there too.
John
Of what I got spec sheets handy (this is far from the complete list)
B&C 15PH40, 15NDL76
Emininence Delta-15A, DeltaLiteII-2515, Kappa-15A, KappaLite3015, Legend-CB15
PA BlueMonster15-CXHA
I've got reason to believe a Sigma 18 might be shoehornable...
4xBeta8's or 4xSammi's with room for a horn in the middle....
A pair of 10's side by side is just too tight, no meat left in the
middle after the holes are cut... Unless your K15 also deviates
from the original width to permit that option.
I've seen a horn mounted in the "shelf" facing up into the top half of
the koupler... That works OK, and maybey even helps break up the
short path around the middle that causes the 250Hz "dip".
I'd go big on VAS, high on sensitivity, high on EBP.
Low as possible on all Q's (including the mechanical).
Low coil overhang (Meaning low XMax and low Le)
Lightest moving mass you can find... A few rings in
the cone are usually a good thing. A cone thats all
ripples is probably too heavy.
The air mass of the coupler will attempt to Lower Fs if the cone
isn't allready too heavy, but the springy air in the box behind the
cone will certainly raise both Fs and Qts... Its a trade that Karlson
balanced extremely well.
I'm running only a DeltaPro12 in my K15 now, not lacking for bass,
which is absolutely astonishing.... Martin 1114 might be a good 12"
choice (the old Eminence coaxial).
Some of the spec sheets may show an on-axis peak. You can bet
there is an equal off-axis drop even if they don't show that detail.
The slot may be helpful evening out the midrange dispersion.
I don't necessarily believe a little rise before Le cutoff is as bad
when seen through a Koupler...
B&C 15PH40, 15NDL76
Emininence Delta-15A, DeltaLiteII-2515, Kappa-15A, KappaLite3015, Legend-CB15
PA BlueMonster15-CXHA
I've got reason to believe a Sigma 18 might be shoehornable...
4xBeta8's or 4xSammi's with room for a horn in the middle....
A pair of 10's side by side is just too tight, no meat left in the
middle after the holes are cut... Unless your K15 also deviates
from the original width to permit that option.
I've seen a horn mounted in the "shelf" facing up into the top half of
the koupler... That works OK, and maybey even helps break up the
short path around the middle that causes the 250Hz "dip".
I'd go big on VAS, high on sensitivity, high on EBP.
Low as possible on all Q's (including the mechanical).
Low coil overhang (Meaning low XMax and low Le)
Lightest moving mass you can find... A few rings in
the cone are usually a good thing. A cone thats all
ripples is probably too heavy.
The air mass of the coupler will attempt to Lower Fs if the cone
isn't allready too heavy, but the springy air in the box behind the
cone will certainly raise both Fs and Qts... Its a trade that Karlson
balanced extremely well.
I'm running only a DeltaPro12 in my K15 now, not lacking for bass,
which is absolutely astonishing.... Martin 1114 might be a good 12"
choice (the old Eminence coaxial).
Some of the spec sheets may show an on-axis peak. You can bet
there is an equal off-axis drop even if they don't show that detail.
The slot may be helpful evening out the midrange dispersion.
I don't necessarily believe a little rise before Le cutoff is as bad
when seen through a Koupler...
Thanks for the info Kenpeter, I' probably going to top mount a waveguide of some kind, although Freddyi over on the Karlson discussion is trying to convince me of the efficacy of the " tube " mounted above the shelf.... I'll probably try it, but primarily now I will use the Koupler as a bass cab.
I've been following the thread over at Audio Karma about the Econo waveguide JBL has out and the relatively inexpensive Comp. drivers from Selenium. I'm also considering the Smith distributed source horn ( 'cause I like working wood, and I can " make " that one ). It has a very wide dispersion capability to hopefully match the Karlson Kabinet.
Duke Lejune has offered me an attractive pair of discontinued Selenium woofers, and opinions vary as to whether they are suitable, in fact they're pretty evenly divided.
Decisions, decisions....
John
I've been following the thread over at Audio Karma about the Econo waveguide JBL has out and the relatively inexpensive Comp. drivers from Selenium. I'm also considering the Smith distributed source horn ( 'cause I like working wood, and I can " make " that one ). It has a very wide dispersion capability to hopefully match the Karlson Kabinet.
Duke Lejune has offered me an attractive pair of discontinued Selenium woofers, and opinions vary as to whether they are suitable, in fact they're pretty evenly divided.
Decisions, decisions....
John
MightyM,
It looks to me like those with more Karlson experience than myself are recommending woofers whose parameters go in a very different direction from the Selenium. If you were doing a straight-forward reflex box the Selenium looks quite good, but now I'm not confident that it would work well in a Karlson.
A great deal on the wrong woofer is a lousy deal in the long run, and it looks like that's what I was offering you.
Duke
It looks to me like those with more Karlson experience than myself are recommending woofers whose parameters go in a very different direction from the Selenium. If you were doing a straight-forward reflex box the Selenium looks quite good, but now I'm not confident that it would work well in a Karlson.
A great deal on the wrong woofer is a lousy deal in the long run, and it looks like that's what I was offering you.
Duke
Kenpeter,
What would you say to this:www.usspeaker.com/DELTAPRO15-1.htm
It's within my price range, cast frame , nice looking response graph at the bottom of the page...
John
What would you say to this:www.usspeaker.com/DELTAPRO15-1.htm
It's within my price range, cast frame , nice looking response graph at the bottom of the page...
John
DeltaPro15A is a fine choice, especially for the low price.
I would encourage you to try a small line array or Smith
on top. I tried several K-Tubes but never got the sound
that Freddyi described, K-Tubes seem a tweaker's night
mare. At least they have been for me.
Follow the proven box and tube designs, don't deviate.
A Koupler is magic only at fine tuned dimensions. Copy
the Transylvania Tube's taper if you insist on going K
on top. Drivers you can experiment all day, its a very
forgiving impedance matcher, but only if the K box or
tube is right first.
K15 might still be the best K of them all. But note the
dimensions on some old drawings assume the back will
be installed with edges showing (not stealth fitted into
the back) you need to adjust the depth of the sides to
accommodate that cosmetic mod before you cut anything!
There should be no deviation on the internal dimensions.
Especially not at the gap behind the rear shelf....
Bracing the wings and/or back with big dowels is usually
said to be beneficial. The wings do shudder a bit at the
lowest notes without bracing (even 13 ply baltic birch!)
Its not something you hear, but you can definately put
your hand on the edge of the wing and FEEL it....
Expect small glass objects to fall off high shelves in the
far unexpected reaches of the house. Don't say I didn't
warn you!
I would encourage you to try a small line array or Smith
on top. I tried several K-Tubes but never got the sound
that Freddyi described, K-Tubes seem a tweaker's night
mare. At least they have been for me.
Follow the proven box and tube designs, don't deviate.
A Koupler is magic only at fine tuned dimensions. Copy
the Transylvania Tube's taper if you insist on going K
on top. Drivers you can experiment all day, its a very
forgiving impedance matcher, but only if the K box or
tube is right first.
K15 might still be the best K of them all. But note the
dimensions on some old drawings assume the back will
be installed with edges showing (not stealth fitted into
the back) you need to adjust the depth of the sides to
accommodate that cosmetic mod before you cut anything!
There should be no deviation on the internal dimensions.
Especially not at the gap behind the rear shelf....
Bracing the wings and/or back with big dowels is usually
said to be beneficial. The wings do shudder a bit at the
lowest notes without bracing (even 13 ply baltic birch!)
Its not something you hear, but you can definately put
your hand on the edge of the wing and FEEL it....
Expect small glass objects to fall off high shelves in the
far unexpected reaches of the house. Don't say I didn't
warn you!
Kenpeter,
Have you looked at the latest patent JEK held, specifically regarding the so called " Figure 6 " diagram. There's a DIYer in the Netherlands who has built cab's to the new layout. The area above the shelves is bent into a smooth arc, and both the front and rear shelves are removed. He seemed very pleased with the results. He also modified the size of the vent.
My own plan is to build a box, and then construct both an updated, braced original interior, and one based on the mods described above, so I can listen to both, then decide which I like and veneer/finish the cabs.
I'm leaning to the Smith DSH, but the materials to do the " tube", are inexpensive so probably will try them too.
John
Have you looked at the latest patent JEK held, specifically regarding the so called " Figure 6 " diagram. There's a DIYer in the Netherlands who has built cab's to the new layout. The area above the shelves is bent into a smooth arc, and both the front and rear shelves are removed. He seemed very pleased with the results. He also modified the size of the vent.
My own plan is to build a box, and then construct both an updated, braced original interior, and one based on the mods described above, so I can listen to both, then decide which I like and veneer/finish the cabs.
I'm leaning to the Smith DSH, but the materials to do the " tube", are inexpensive so probably will try them too.
John
Unless you got a better plan to lengthen the acoustic short circuit
from back to front (of the loudspeaker) through the central vent, I
would leave those shelves in place. Even with shelves, there is a
dip in the response at 250Hz.
You need one traditional K15 for reference before you go hacking.
Its wayyyy too easy to wind up with something "else" that don't
have half the magic a Karlson is famous for. Without a reference
you might settle without ever knowing what you had missed!
Now if I had a way to switch out more of the guts (and I can
change out my wings and speaker baffle pretty easy, as I had
planned ahead to upgrade my undersized DeltaPro12 when I
could afford to do so)
The mods I would lean toward a fuller shelf, such that it touches
and braces the wings and back. I would cut holes in the shelf or
leave vents at the sides. And probably cut back a moon shaped
clearance right near the front slot. So's no to fool with how it
functions as a K-Koupler too much. Basically lengthen and De-Q
the short circuit paths without changing any of the other tunings.
But that might be an impossibly complicated goal.
I doubt Fig 6 matters unless there was no shelf in front.
And I'd take a shelf over Fig 6 any day....
from back to front (of the loudspeaker) through the central vent, I
would leave those shelves in place. Even with shelves, there is a
dip in the response at 250Hz.
You need one traditional K15 for reference before you go hacking.
Its wayyyy too easy to wind up with something "else" that don't
have half the magic a Karlson is famous for. Without a reference
you might settle without ever knowing what you had missed!
Now if I had a way to switch out more of the guts (and I can
change out my wings and speaker baffle pretty easy, as I had
planned ahead to upgrade my undersized DeltaPro12 when I
could afford to do so)
The mods I would lean toward a fuller shelf, such that it touches
and braces the wings and back. I would cut holes in the shelf or
leave vents at the sides. And probably cut back a moon shaped
clearance right near the front slot. So's no to fool with how it
functions as a K-Koupler too much. Basically lengthen and De-Q
the short circuit paths without changing any of the other tunings.
But that might be an impossibly complicated goal.
I doubt Fig 6 matters unless there was no shelf in front.
And I'd take a shelf over Fig 6 any day....
Kenpeter,
Thanks for the reply, since both have the same 30 deg. speaker baffle, I think that I can construct a slide-in ( more or less ) baffle, and all the accutremonts. ( I may at a later date wish to eat those words too... ) So as to do just as you recomend. Have the K-15 as designed, and as JanS over in europe modded his too. I think that before this project is complete I will have to break down and put together some test equip., my poor old ears will just not cut it anymore in the age of the internet.
John
Thanks for the reply, since both have the same 30 deg. speaker baffle, I think that I can construct a slide-in ( more or less ) baffle, and all the accutremonts. ( I may at a later date wish to eat those words too... ) So as to do just as you recomend. Have the K-15 as designed, and as JanS over in europe modded his too. I think that before this project is complete I will have to break down and put together some test equip., my poor old ears will just not cut it anymore in the age of the internet.
John
Nice list Andrea, Thanks,
glad you thought of this thread. I've a bit more reading to do on your pages.
Have you considered ( since low cost is an objective ) the Econowave project on Audio Karma for the top end? Crossover design work is already done, with a dedicated high efficiency design available.
Would require a higher crossover, but several of the woofers you list would appear to be good candidates, with linearity to 4K.
Have you run any of the listed woofers through Cyr-Marc's Onken Calculator? to see if they are suitable for use in that bass alignment?
Are the Monacor's available in the US?, I didn't see a distributor on their site.....
John
glad you thought of this thread. I've a bit more reading to do on your pages.
Have you considered ( since low cost is an objective ) the Econowave project on Audio Karma for the top end? Crossover design work is already done, with a dedicated high efficiency design available.
Would require a higher crossover, but several of the woofers you list would appear to be good candidates, with linearity to 4K.
Have you run any of the listed woofers through Cyr-Marc's Onken Calculator? to see if they are suitable for use in that bass alignment?
Are the Monacor's available in the US?, I didn't see a distributor on their site.....
John
Andrea,
Here's a link to the thread, but I warn you it's rather long, over 5K postings, and at times "chatty". Wayne Parham, and Dr. Earl Gedde's have both checked in. I found the information regarding the XO design and testing fascinating, not having yet designed my own XO. The page I linked may help in that someone has appended some of the needed information onto the first entry.
www.audiokarma.org/forums/showthread.php?t=150939
This monster has been referred to on several other forums I lurk in too.
John
Here's a link to the thread, but I warn you it's rather long, over 5K postings, and at times "chatty". Wayne Parham, and Dr. Earl Gedde's have both checked in. I found the information regarding the XO design and testing fascinating, not having yet designed my own XO. The page I linked may help in that someone has appended some of the needed information onto the first entry.
www.audiokarma.org/forums/showthread.php?t=150939
This monster has been referred to on several other forums I lurk in too.
John
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