@rchamber -
I think GM brought that up to illustrate there was some sane pre-TS thought going on regarding properly sizing bass reflex boxes.
Karlson enclosures likewise would have some size limits. I have run strong 12" (KN 612HC) in K15, very weak 15" (EV SP15B), Audio Nirvana super10, all with enjoyable enough results. I never ran my nemesis 12LTA - that might have been a good match to extract some power from the weak motor.
I think GM brought that up to illustrate there was some sane pre-TS thought going on regarding properly sizing bass reflex boxes.
Karlson enclosures likewise would have some size limits. I have run strong 12" (KN 612HC) in K15, very weak 15" (EV SP15B), Audio Nirvana super10, all with enjoyable enough results. I never ran my nemesis 12LTA - that might have been a good match to extract some power from the weak motor.
Tuned how low? The 416A [~3-4 mm Xmax] is designed for ~20-25 Hz [measured Fs] FLH, though normally tuned to ~ 42-55 Hz in the cinema reflex horns whereas the K15 is designed for the 50-60 Hz 604B, C with its ~1-2.5 mm Xmax.
Not really sub duty unless there's significant room gain and/or ~100 dB transient peaks is adequate.
You've got measurements of the original, right? Please post it.
Regardless, as I've posted before, to my then very young ears I thought it had an incredible low end only matched/bested by live band instruments and larger movie theater systems, it was otherwise a horrible sounding speaker overall [15" whizzer cone] that much later learned it equated to a ~ 2.5 octave device, so for me its HF BW is dependent on its tuning whereas Karlson rated it to at least 1600 Hz for the 604 duplexes.
😀 Looking forward to a review/critique as its collection of tuned boxes that has been a 'Black Sheep'/'crackpot' design since day one and generally dismissed 'out of hand' due more to its marketing and widely misunderstood 'physics of the situation' than actual usage.
I've owned Tympani 1D, Maggies, Acoustat, teesny Rogers, VMPS, still have 3 K-horns, custom RCA Fan horn, Bruce's Monolith and 100Hz straight horns and have great respect for K15 vs reflex and compromised horn.
K's claims (he wasn't the only one in those days) were bigger than reality but the arrangement can widen horizontal polars, reduce cone excursion to less than half of a similar reflex, reduce distortion.
There's the story that shortly before K passed he sold the patent to a big player (without his wife's knowledge). Sometime after JEK passed, Mrs K in turn sold rights to a number of companies who simultaneously manufactured the little coupler based upon X15. That included Westwood, Acoustic Control, KK-Audio, Transylvania Power Company, and KHS. When the big name company got wind of one of these makers they said shut down or be sued.
Exemplar made good use of K15 as a subwoofer and the elite horn manufacturer "Cogent"'s team has great respect for the design. (Steve likes K15 with field coil driver)
K's claims (he wasn't the only one in those days) were bigger than reality but the arrangement can widen horizontal polars, reduce cone excursion to less than half of a similar reflex, reduce distortion.
There's the story that shortly before K passed he sold the patent to a big player (without his wife's knowledge). Sometime after JEK passed, Mrs K in turn sold rights to a number of companies who simultaneously manufactured the little coupler based upon X15. That included Westwood, Acoustic Control, KK-Audio, Transylvania Power Company, and KHS. When the big name company got wind of one of these makers they said shut down or be sued.
Exemplar made good use of K15 as a subwoofer and the elite horn manufacturer "Cogent"'s team has great respect for the design. (Steve likes K15 with field coil driver)
GM - as I've mentioned for over a decade, Exemplar tuned K15 "low" with two 3" right angle PVC elbows. That was around 30Hz. I used Altec 416 but did take that one Z-input graph with a 421.
with an Altec 416Z, some parametric boost around fb, an 80Hz xover to a distributed slit vent K12 and weak motor Lafayette (??) cheap 12CX , my theatre organ CD's never sounded better. Two Sanders' 10ft t-lines were horrible in comparison and if I had still owned it, my Hegeman Contrabombarde would not have kept up with it.
John Tucker was proud that he could run the low tuned K15 on 20 watts.
Put the wrong balanced driver in K15 and it will be horrible - IIRC that can happen too with horn and DR.
"The Spirit of Koussevitzky " bowed bass album sounded great imo with K15 and 604B re-coned to "E"). The same cabinet sounded pretty good with Hans Hotter's "Winterreise"
My K12 with TSG 12cx plays Fritz Wunderlich's DGG lieder CD nice.
Even the 12LTA I complain about (Hey lets for real do a go fund me, etc. to get one built with a real motor - just one of EM's 54-56oz slugs should to the trick)
A pair of K15 with Eminence C15CX - good enuff for me with Sgt. Peppers
One quick rig I liked with a horn was with a 30 inch wide by 27" deep radial horn and Altec 1" for midrange coming in around 700Hz - upper duty was with a ring radiator. That sounded much better than Bruce's LE5 tractrix on top of K15. That was probably the best I heard Nick Cave including what few FR I have.
My health is about shot from 25 years of obstructive apnea then hypertropic cardiomyopathy then time on a ventilator from an allergic reaction two years back so for Karlson stuff to be defended and explained in the future, it will take new blood. XRK971 will be one of those (maybe the only - lol) to keep it on track.
Crackpot or not - I think there's some fun and good times to be had.
My house has real problems and my poor kid and his GF take care of me - it drives them nuts as I'm materially attached to cluttering audio stuff.
I do have "this" to piddle with it - - - not my horns and regular K's anymore.
BEST !
F
with an Altec 416Z, some parametric boost around fb, an 80Hz xover to a distributed slit vent K12 and weak motor Lafayette (??) cheap 12CX , my theatre organ CD's never sounded better. Two Sanders' 10ft t-lines were horrible in comparison and if I had still owned it, my Hegeman Contrabombarde would not have kept up with it.
John Tucker was proud that he could run the low tuned K15 on 20 watts.
Put the wrong balanced driver in K15 and it will be horrible - IIRC that can happen too with horn and DR.
"The Spirit of Koussevitzky " bowed bass album sounded great imo with K15 and 604B re-coned to "E"). The same cabinet sounded pretty good with Hans Hotter's "Winterreise"
My K12 with TSG 12cx plays Fritz Wunderlich's DGG lieder CD nice.
Even the 12LTA I complain about (Hey lets for real do a go fund me, etc. to get one built with a real motor - just one of EM's 54-56oz slugs should to the trick)
A pair of K15 with Eminence C15CX - good enuff for me with Sgt. Peppers
One quick rig I liked with a horn was with a 30 inch wide by 27" deep radial horn and Altec 1" for midrange coming in around 700Hz - upper duty was with a ring radiator. That sounded much better than Bruce's LE5 tractrix on top of K15. That was probably the best I heard Nick Cave including what few FR I have.
My health is about shot from 25 years of obstructive apnea then hypertropic cardiomyopathy then time on a ventilator from an allergic reaction two years back so for Karlson stuff to be defended and explained in the future, it will take new blood. XRK971 will be one of those (maybe the only - lol) to keep it on track.
Crackpot or not - I think there's some fun and good times to be had.
My house has real problems and my poor kid and his GF take care of me - it drives them nuts as I'm materially attached to cluttering audio stuff.
I do have "this" to piddle with it - - - not my horns and regular K's anymore.
BEST !
F
Attachments
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Markwart and Tucker's Karlsons
an old Audio Asylum review on the Exemplar Karlson subwoofer
High Efficiency Speaker Asylum
an old Audio Asylum review on the Exemplar Karlson subwoofer
High Efficiency Speaker Asylum
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Hi freddi,
Of what material are those *"pads"* that show in the 1954 Radio and Television News drawing made...blocks of wood, or?
For my woofer/subwoofer build, would you recommend building with the original rectangular ~?*"x4.5" vent, such that the Exemplar dual 3" elbow vent could be added later with an insert panel if desired?
Best, Robert
* I'm having trouble reading the slant height dimension of the speaker mounting board up to the shelf on the 1954 drawing...what is it...15.75", or 19.75", or? If it's 19.75" (which seems likely since the slant distance up to the driver centerline is 10"), the port height is 9.02", not 9.5", not 11.25" mentioned by SoundRight.
Hi Robert
-
those pads were fiberglass, rockwool - later probably "Kiomsul" (a nice paper insulation product not made anymore)
I would make the 9" x4.5" vent shown in the January 1954Radio and Television News article - but if you intend it only as a subwoofer, you could make the port panel to directly accommodate two schedule 40 rt. angle pvc elbows.
Tuned with the original vent, it will have articulate punchy bass which extends to around 50Hz reasonably flat - depending upon room.
-
those pads were fiberglass, rockwool - later probably "Kiomsul" (a nice paper insulation product not made anymore)
I would make the 9" x4.5" vent shown in the January 1954Radio and Television News article - but if you intend it only as a subwoofer, you could make the port panel to directly accommodate two schedule 40 rt. angle pvc elbows.
Tuned with the original vent, it will have articulate punchy bass which extends to around 50Hz reasonably flat - depending upon room.
Hi freddi,
Thank you for the detail of the plan...it helped me to confirm the 19 3/4" slant height dimension, thus the 9" port height.. Also, thanks for the scoop on the "pads"!
I was originally thinking of scratch building a single enclosure...but...along comes a pair of vintage, nice looking - like K15s, with what appear to be their original Utah 15" co-ax drivers on ebay, Item Number 164812341714. Free pickup in Greensboro, NC...but alas, I'm in Corinth, Vermont, ~850 miles and a 13 hour drive away. I've submitted a request for quote on crating and freighting them here...expect reply tomorrow.
We shall see what we shall see. 🙂
Very Best to You,
Robert
Thank you for the detail of the plan...it helped me to confirm the 19 3/4" slant height dimension, thus the 9" port height.. Also, thanks for the scoop on the "pads"!
I was originally thinking of scratch building a single enclosure...but...along comes a pair of vintage, nice looking - like K15s, with what appear to be their original Utah 15" co-ax drivers on ebay, Item Number 164812341714. Free pickup in Greensboro, NC...but alas, I'm in Corinth, Vermont, ~850 miles and a 13 hour drive away. I've submitted a request for quote on crating and freighting them here...expect reply tomorrow.
We shall see what we shall see. 🙂
Very Best to You,
Robert
Many thanks ! - I'm on a cheap TV as a monitor so its tough to see some color differences.
By free air - do you mean "2 pi" ?
I'd imagine some bass players loaded K145 into K15. (What woofer did Stanly Clarke use in his Alembic K?)
IMO K15 can play pretty loud with very little cone excursion and seemed to have less excursion below cutoff vs same (JBL M151) speaker in a reflex the size of K15's rear chamber and same system tuning (~48Hz).
Where would you say K15's front chamber is tuned ?
Best,
Freddy
By free air - do you mean "2 pi" ?
I'd imagine some bass players loaded K145 into K15. (What woofer did Stanly Clarke use in his Alembic K?)
IMO K15 can play pretty loud with very little cone excursion and seemed to have less excursion below cutoff vs same (JBL M151) speaker in a reflex the size of K15's rear chamber and same system tuning (~48Hz).
Where would you say K15's front chamber is tuned ?
Best,
Freddy