freddi said:
Hey Freddy!
Just copy the image url into the IMG box after you click on the IMG box- the IMG button appears above the reply box when you are replying to a post.
Nice seeing you here.
Freddy is probably the worlds most intense Karlson experimenter.. !
An externally hosted image should be here but it was not working when we last tested it.
re:dip - probably related to path length difference vs cone's path to ground. Cabinet was standing upright outdoors - should had laid it on side to see what things looked like. Rear loaded horns probably have this dip too - note it went away when vent was blocked. - this was 1/24 octave resolution which is farily brutal trace-wise.
with regular Karlson Ultra Fidelity type, outdoor dips looks somewhat less drastic if cabinet is tilted forwards by baffle angle (or more)
hey Mag - good to be anywhere at my age - haha
with regular Karlson Ultra Fidelity type, outdoor dips looks somewhat less drastic if cabinet is tilted forwards by baffle angle (or more)
hey Mag - good to be anywhere at my age - haha
Then he says:
So there are dips, or aren't there? One is trying to imagine a basis for the claim that there is no baffle step or floor bounce.
Karlsons seem to appeal to people who have little real knowledge of acoustics - they are a magic recipe that does not need to mind the intimidating laws of physics. People believe it all because some crackpot wrote an article about them almost 50 years ago. Although nobody could duplicate his results or verify his claims with any of the drivers the enclosure was supposedly designed for, people of like mind continue to carry the torch for this outdated design and assign to it properties that were not even in the original and completely unproven claims.
BTW, them dips in the "TL" with the cute slot are caused by line resonances in the pipe. The differing frequency is because the line is effectively shorter with the neat-looking slot. Pretty cool the gain which was achieved relative to a sealed box - yet the presumably rectangular slot results show quite clearly there is no magic with the slot over a standard TL. Now add a vented box plot, if you dare
.BTW, have I heard them? Yes, several different pair. Often they have impressive sensitivity as compared to most modern designs....but this is due to the driver, not the slot - and true for many 50's vintage designs. Have I lived with them long enough to convince myself they are the ultimate? No.
But hey, sound is all subjective. I always appreciate opinions, but it takes real evidence to prove something to someone who is really interested in how things work.
Cool, nice to see you here !
Quoted from on other thread here on diyaudio (Wich sub goes down to 20Hz...)
How a karlson should be tuned ? What did you do to achieve bass like 30 Hz ? (Does it mean 30Hz @ -3dB ?)
Understand. Otherwise thats exactly my basic question about the Karlson theory.
In my view an exponential cut in 2/3 length, helps only inside the tube to stop
acoustic shortcircuit (or shortcircuit is the right word ?
), but from outsideits increase it, due to the bigger, longer vent, doesnt ?
Ron E said:
There are dips beyond the area I use them, some folks like to use Karlson's full range. I hear the dips and only use couplers in the bass with a 4th order lowpass. The dip can be moved up or down in my Klams by changing the angle of the slot or/and the size of the front chamber. The first narrow band dip is around 40 cycles wide, 10 db down and centered at 350 cycles. When the whole front chamber is removed the entire response in the 60-300 cycle range is shelved down 3-12 db. This is caused by lack of baffle and wall/floor reflections = How is this true? I have measured the Klams outside with and without the chamber/slot, I have also extended the the front baffle of the Klam without the front chamber/slot and observed less baffle loss - My Klams are 22" wide. If you do not find this as 'proof' I do not care and will continue to enjoy the benefit of the higher efficiency and overall better bass quality of my Klams over other designs.
AFA your statement regarding the the hocus Pocus or unfounded belief of people that appreciate what the Karlsons do for them I believe you are full of poop. Sure the Karlson papers are full of mad claims, but they do not cancel out what I observe. If you beleive adding a front chamber in front of a driver with a long expo slot does nothing to the response then you have no real knowledge of acoustics.
The same drivers are used in the above example with and without the chamber and yes the drivers are good HE ones - and yes they sound better in the KLAM then they do in a BR, IB, or the horns I've loaded them in. It's not the driver, it's the way they are loaded.
I have never built a TL using a slot for a vent - to me it would make a difference but probably be no better or worse then a proper terminated vent.
I have built Karlson tubes and loaded them with both cones and compression drivers and yes the do work well but IMO they just don't sound as good as a proper horn. I think it's due to the reflections in the tube and the ultra wide radiation in my narrow room.
since "real" Karlson have front chambers - things a-happening in chamber and at slot
how to view? - uh -guess could range from JEK's view to "a tone-chamber"- JEK in a 1950 invention list termed this particular invention as having "controlled reverbration"- or "controlled ring" and in his opinion added a sense of realism by enchancing 'weak transients' (this was part of JEK's reguirements for realism in his 1952 Audio Engineering article) - reverb in recordings natural or not can be useful for enhancing the illusion.
imo with Ultra-fidelity type ( and larger klam) theres a vortex gun type shockwave experience and reasonably taut damping on strong passages - a badly (wimpy Q) loaded k12 can sound like a piece of samsonite luggage whomped with a foam ballbat. if balance/motor/HF favorable then similar bulk (4.2cu.ft) x15 can do a pretty good bass drum illusion despite ~70Hz half space corner
theres a peak in some K around the 3rd Z input region - but some 'horn' can exhibit peak too. I might be tempted with some k's to EQ a bit
Carl and Wayne Neuser are the intense K-guys - but don't publish data nor plans - have many prototype, etc. - Carl is automotive engineer w. math degrees and FWIW tests each coupler with several sets of CNC tapers, varied back volume, etc. then once coupler is tweaked - they do another and A-B. Their k-belief system may be stronger than mine. that said - Karlson are still interesting and imo may lower modulation distortion - cone motion seems lsss below passband than a reflex same size a K15's rear chamber. Contour (Punisher horn) believes this aso). my two-tone sine test appears to show a reduction in sideband ampplitude. (distributive vent many not look good under sine conditions)
Two-tone: Beta 15CX run in 3.6cu.ft. 50Hz reflex and in Karlson 15
re: Fulmerized T-lines - slotted pipe will act shorter
k-tubes are interesting and can sound fine although ~no gain - easiest would be a rolled paper version of Transylvania Power Company's ""The Tube" - ~5.3" long, half-ellipse based slot (The Tube tapered downwards a few degrees) - 1"ID pvc pipe ~5.3" long is good too. longer slot might make them more directive in horizontal (?)
KARLSON AND KARLSON-RELATED SPEAKER PATENTS
RELATED:
W.O Swinyard US 2020166 filed 1935 “Sound Reproduction Apparatus” - a wedge-shaped 20 degree coupler with “V” deflector having non-parallel walls -
“Proto-Karlson”!
N.C. Fulmer US 2787332 filed 1952 “Loud-Speaker System” - a folded 1/4 wave pipe with last section broadbanded with tapered slot - Fulmer’s patent apparently conflicted with Karlson’s 1st “Acoustic Transducers” (plus RCA claims) delaying grants on both.
R-J Enclosure:
(1) "The R-J Speaker Enclosure" by William Joseph and Franklin Robbins. Published in Audio Engineering Magazine December 1951.
(2) "Practical Aspects of the R-J Speaker Enclosure" by William Joseph and Franklin Robbins Published in Audio Engineering Magazine January 1953.
***************
"Acoustic System for Loud-Speaker" US# 2694463; Robbins et al filed April 17, 1952 granted 11/54
John A. McKenzie US 3590941 filed 1969 “Speaker Enclosure”
Robert W. Reams US 4196790 filed 1978 “Acoustic Transducer having Multiple Frequency Resonance
Rodden, M. Raymond US 4313521 filed Feb. 2 1982 "Speaker Housing"
Weiss et al US 5943431 August 24, 1999 “Loudspeaker With Tapered Slot Coupler And Sound Reproduction System”
KARLSON PATENTS:
J.E. Karlson US 2586827 “Directive Radiating System” Filed March 31 1945
J.E. Karlson “Acoustic Transducers” US 2816619 filed Dec. 1951, granted 6 years later - (probaby due to RCA and Olson - Karlson won over RCA claims)
J.E Karlson “Acoustic System” US 2896736 filed Aug. 1955 - (referenced by Bose)
J.E. Karlson “Open End Waveguide Antenna” US 3445852 filed 1968
J.E. Karlson “Acoustic Transducers” - US 3540544 filed 1968
J.E. Karlson “Jet Engine Silencer Nozzle...) US 3543876 filed 1968
LIST OF INVENTIONS 4/24/50
J.E. (Edward) Karlson
1. ELECTRONIC POTENTIOMETER. A variable element which is capable of linear variations of resistances with infinitesimal mechanical motion yet also have capabilities of broad variations in resistance.
2. CAPLESS DISPENSING TUBE. This device permits the use of toothpaste tubes, etc. without the necessity and bother of removing and replacing the cap after each usage.
3. GEOLOGICAL PROSPECTING SYSTEM. A system for use in the prospecting for oil, minerals, etc. This system may also be used for radar applications.
4. RADAR ANTENNA WITH AUTOMATICALLY VARIABLE BEAM PATTERN. This invention provides a simple means of automatically changing the beam pattern of a radar antenna from a pencil beam to a cosecant beam.
5. DIELECTRIC ANTENNA. This invention provides a technique for designing commercial and military antennas which will have overall dimensions than conventional antennae, and yet have equivalent gain and directivity characteristics.
6. BRUSHLESS DC MOTOR
7. ASHTRAY. An extremely simple design for an ash tray which quickly extinguishes cigarettes.
8. PRECISION DELAY CIRCUIT. This circuit provides a delayed pulse at a precise interval following an initial pulse.
9. CHATTERLESS CONTACTS FOR RELAYS
10. TELEVISION ANTENNA. This invention provides a simple, low cost antenna which can be readily hidden or obscured in the average room and is suitable for both F.M. and television.
11. SLOT ANTENNA. This design provides a slot antenna with broad band matching possibilities.
12. HYBRID WAVEGUIDE JUNCTION. This is a wave guide section which has variable propagation characteristics dependant upon the direction of propagation.
13. R.F. TUNER. a simplified tuner for F.M. and television use.
14. ADVERTISING SIGN. Novel electric sigh with quick change possibilities.
15. LIGHT VALVE FOR TELEVISION PROJECTION AND PICKUP TUBE.
16. ACOUSTIC TRANSDUCER. A novel loudspeaker enclosure with improved matching characteristics and controlled reverberation.
17. FISHING DEVICE
18. TELEPHONE AMPLIFIER WITH SPECIAL ACOUSTIC CHARACTERISTICS
how to view? - uh -guess could range from JEK's view to "a tone-chamber"- JEK in a 1950 invention list termed this particular invention as having "controlled reverbration"- or "controlled ring" and in his opinion added a sense of realism by enchancing 'weak transients' (this was part of JEK's reguirements for realism in his 1952 Audio Engineering article) - reverb in recordings natural or not can be useful for enhancing the illusion.
imo with Ultra-fidelity type ( and larger klam) theres a vortex gun type shockwave experience and reasonably taut damping on strong passages - a badly (wimpy Q) loaded k12 can sound like a piece of samsonite luggage whomped with a foam ballbat. if balance/motor/HF favorable then similar bulk (4.2cu.ft) x15 can do a pretty good bass drum illusion despite ~70Hz half space corner
theres a peak in some K around the 3rd Z input region - but some 'horn' can exhibit peak too. I might be tempted with some k's to EQ a bit
Carl and Wayne Neuser are the intense K-guys - but don't publish data nor plans - have many prototype, etc. - Carl is automotive engineer w. math degrees and FWIW tests each coupler with several sets of CNC tapers, varied back volume, etc. then once coupler is tweaked - they do another and A-B. Their k-belief system may be stronger than mine. that said - Karlson are still interesting and imo may lower modulation distortion - cone motion seems lsss below passband than a reflex same size a K15's rear chamber. Contour (Punisher horn) believes this aso). my two-tone sine test appears to show a reduction in sideband ampplitude. (distributive vent many not look good under sine conditions)
Two-tone: Beta 15CX run in 3.6cu.ft. 50Hz reflex and in Karlson 15
An externally hosted image should be here but it was not working when we last tested it.
re: Fulmerized T-lines - slotted pipe will act shorter
k-tubes are interesting and can sound fine although ~no gain - easiest would be a rolled paper version of Transylvania Power Company's ""The Tube" - ~5.3" long, half-ellipse based slot (The Tube tapered downwards a few degrees) - 1"ID pvc pipe ~5.3" long is good too. longer slot might make them more directive in horizontal (?)
KARLSON AND KARLSON-RELATED SPEAKER PATENTS
RELATED:
W.O Swinyard US 2020166 filed 1935 “Sound Reproduction Apparatus” - a wedge-shaped 20 degree coupler with “V” deflector having non-parallel walls -
“Proto-Karlson”!
N.C. Fulmer US 2787332 filed 1952 “Loud-Speaker System” - a folded 1/4 wave pipe with last section broadbanded with tapered slot - Fulmer’s patent apparently conflicted with Karlson’s 1st “Acoustic Transducers” (plus RCA claims) delaying grants on both.
R-J Enclosure:
(1) "The R-J Speaker Enclosure" by William Joseph and Franklin Robbins. Published in Audio Engineering Magazine December 1951.
(2) "Practical Aspects of the R-J Speaker Enclosure" by William Joseph and Franklin Robbins Published in Audio Engineering Magazine January 1953.
***************
"Acoustic System for Loud-Speaker" US# 2694463; Robbins et al filed April 17, 1952 granted 11/54
John A. McKenzie US 3590941 filed 1969 “Speaker Enclosure”
Robert W. Reams US 4196790 filed 1978 “Acoustic Transducer having Multiple Frequency Resonance
Rodden, M. Raymond US 4313521 filed Feb. 2 1982 "Speaker Housing"
Weiss et al US 5943431 August 24, 1999 “Loudspeaker With Tapered Slot Coupler And Sound Reproduction System”
KARLSON PATENTS:
J.E. Karlson US 2586827 “Directive Radiating System” Filed March 31 1945
J.E. Karlson “Acoustic Transducers” US 2816619 filed Dec. 1951, granted 6 years later - (probaby due to RCA and Olson - Karlson won over RCA claims)
J.E Karlson “Acoustic System” US 2896736 filed Aug. 1955 - (referenced by Bose)
J.E. Karlson “Open End Waveguide Antenna” US 3445852 filed 1968
J.E. Karlson “Acoustic Transducers” - US 3540544 filed 1968
J.E. Karlson “Jet Engine Silencer Nozzle...) US 3543876 filed 1968
LIST OF INVENTIONS 4/24/50
J.E. (Edward) Karlson
1. ELECTRONIC POTENTIOMETER. A variable element which is capable of linear variations of resistances with infinitesimal mechanical motion yet also have capabilities of broad variations in resistance.
2. CAPLESS DISPENSING TUBE. This device permits the use of toothpaste tubes, etc. without the necessity and bother of removing and replacing the cap after each usage.
3. GEOLOGICAL PROSPECTING SYSTEM. A system for use in the prospecting for oil, minerals, etc. This system may also be used for radar applications.
4. RADAR ANTENNA WITH AUTOMATICALLY VARIABLE BEAM PATTERN. This invention provides a simple means of automatically changing the beam pattern of a radar antenna from a pencil beam to a cosecant beam.
5. DIELECTRIC ANTENNA. This invention provides a technique for designing commercial and military antennas which will have overall dimensions than conventional antennae, and yet have equivalent gain and directivity characteristics.
6. BRUSHLESS DC MOTOR
7. ASHTRAY. An extremely simple design for an ash tray which quickly extinguishes cigarettes.
8. PRECISION DELAY CIRCUIT. This circuit provides a delayed pulse at a precise interval following an initial pulse.
9. CHATTERLESS CONTACTS FOR RELAYS
10. TELEVISION ANTENNA. This invention provides a simple, low cost antenna which can be readily hidden or obscured in the average room and is suitable for both F.M. and television.
11. SLOT ANTENNA. This design provides a slot antenna with broad band matching possibilities.
12. HYBRID WAVEGUIDE JUNCTION. This is a wave guide section which has variable propagation characteristics dependant upon the direction of propagation.
13. R.F. TUNER. a simplified tuner for F.M. and television use.
14. ADVERTISING SIGN. Novel electric sigh with quick change possibilities.
15. LIGHT VALVE FOR TELEVISION PROJECTION AND PICKUP TUBE.
16. ACOUSTIC TRANSDUCER. A novel loudspeaker enclosure with improved matching characteristics and controlled reverberation.
17. FISHING DEVICE
18. TELEPHONE AMPLIFIER WITH SPECIAL ACOUSTIC CHARACTERISTICS
oops - re:eXemplar's tuning - take two 3"ID right angle ducts - mount to board and attach over original Karlson 15 port - to work it probalby needs high vas low fs driver - IIRC eXemplar used 515
re:-3dB - imagine outdoors response would loolk someting like a sealed box for "awhile" - maybe 6 then 12dB slope to around fb going into 3rd - 4th order
if can muster up strength then might try to load a k15 - but would have to find vents, move a dozen cabinets, take cabinet down then back up a ramp.
FWIW - here's some old in-room warble of K15
EXEMPLAR ULTRA-FIDELITY SUBWOOFER MOD re-tuned to ~30Hz via 2-3 Inch ID PVC Elbows
Altec 416 in UF with 2-3"ID elbows vs Altec 416 in UF with 4.5"x9" port vs an Emiennce - Dayton 295-070 in reflex tuned ~30
not much diff between a 3.6 or so 30Hz reflex and low-tuned Karslon - imo the reflex sounded poor - may have been the "Magnum" type driver? (round-wound not edgewound coil) vs Altec 416 (did not have 416 in B6 reflex for subjective comparison)
20Hz Vented=70dB;- mod UF 416=67.3db;-stock UF 416=60.3dB
22Hz Vented=72dB;- mod UF 416=69.3dB;-stock UF 416=62dB
25Hz Vented=73dB;- mod UF 416=70dB;- stock UF 416=62dB
28Hz Vented=74.3dB-;mod UF 416=79.2dB;- stock UF 416=66dB
32Hz Vented=80dB;- mod UF 416=79.2dB;- stock UF 416=72.3dB
36Hz Vented=85.5dB;- mod UF 416=85dB;- stock UF 416=82.5dB
40Hz Vented=90dB;- mod UF 416=88.6dB;- stock UF 416=86.2dB
45Hz Vented=90.4dB;- mod UF 416=91dB;- stock UF 416=89.9dB
50Hz Vented=90dB;- mod UF 416=91.4dB;- stock UF 416=91.6dB
56Hz Vented=88.3dB;- mod UF 416=90dB;- stock UF 416=91.9dB
63hz Vented=88.9dB;- mod UF 416=89.2dB;-stock UF 416=92.3dB
71Hz Vented=94dB;- mod UF 416=93.5dB;- stock UF 416=97.6dB
80Hz Vented=98dB;- mod UF 416=98.5dB;-stock UF 416=100.7dB
90Hz Vented=97.4dB;- mod UF 416=99.3dB;- stock UF 416=101.2
re:-3dB - imagine outdoors response would loolk someting like a sealed box for "awhile" - maybe 6 then 12dB slope to around fb going into 3rd - 4th order
if can muster up strength then might try to load a k15 - but would have to find vents, move a dozen cabinets, take cabinet down then back up a ramp.
FWIW - here's some old in-room warble of K15
EXEMPLAR ULTRA-FIDELITY SUBWOOFER MOD re-tuned to ~30Hz via 2-3 Inch ID PVC Elbows
Altec 416 in UF with 2-3"ID elbows vs Altec 416 in UF with 4.5"x9" port vs an Emiennce - Dayton 295-070 in reflex tuned ~30
not much diff between a 3.6 or so 30Hz reflex and low-tuned Karslon - imo the reflex sounded poor - may have been the "Magnum" type driver? (round-wound not edgewound coil) vs Altec 416 (did not have 416 in B6 reflex for subjective comparison)
20Hz Vented=70dB;- mod UF 416=67.3db;-stock UF 416=60.3dB
22Hz Vented=72dB;- mod UF 416=69.3dB;-stock UF 416=62dB
25Hz Vented=73dB;- mod UF 416=70dB;- stock UF 416=62dB
28Hz Vented=74.3dB-;mod UF 416=79.2dB;- stock UF 416=66dB
32Hz Vented=80dB;- mod UF 416=79.2dB;- stock UF 416=72.3dB
36Hz Vented=85.5dB;- mod UF 416=85dB;- stock UF 416=82.5dB
40Hz Vented=90dB;- mod UF 416=88.6dB;- stock UF 416=86.2dB
45Hz Vented=90.4dB;- mod UF 416=91dB;- stock UF 416=89.9dB
50Hz Vented=90dB;- mod UF 416=91.4dB;- stock UF 416=91.6dB
56Hz Vented=88.3dB;- mod UF 416=90dB;- stock UF 416=91.9dB
63hz Vented=88.9dB;- mod UF 416=89.2dB;-stock UF 416=92.3dB
71Hz Vented=94dB;- mod UF 416=93.5dB;- stock UF 416=97.6dB
80Hz Vented=98dB;- mod UF 416=98.5dB;-stock UF 416=100.7dB
90Hz Vented=97.4dB;- mod UF 416=99.3dB;- stock UF 416=101.2
Just wondering Freddy, are there two folds in that box so the 9 ft length is roughly 3 times the 3 ft height?
Do you have input impedance plots for each condition?
Is the closed box response simply with the port covered or also with any internal baffles removed?
That looks very similar to what I built many years ago but they were 6 ft towers with no folds, the slot was only about one third that height, and I used damping on the walls. I used a pair of 8" woofers in each.
Thanks,
Pete B.
Do you have input impedance plots for each condition?
Is the closed box response simply with the port covered or also with any internal baffles removed?
That looks very similar to what I built many years ago but they were 6 ft towers with no folds, the slot was only about one third that height, and I used damping on the walls. I used a pair of 8" woofers in each.
Thanks,
Pete B.
Magnetar said:
freddi said:
Hey Freddy - I had some interesting results with an Audax PR170MO loaded in a four foot 6" diameter tube with a 2/3 length slot. The driver was in a .5 cubic foot sealed box. I simply laid the box on the ground pointing up and placed the tube on the front of the driver. In the box alone the driver was usable 500-5K, in the tube it went to 150-5k - IOW there was gain but only below 500 Hz - Also loaded a JBL 2440 in the same tube with just the driver firing into it, IE the 2" exit to the 6" tube - Here again there was gain in the lower range. The 2440 went down to 350 cycles (ragged) -
Someday I'd like to load one of my 6.5" Tannoy coaxials in a tube and see how it does - seems it would make a great surround speaker with it's open radiation.
@Pete - line was 48H x13W x18D ~10ft path design by Roger Sanders in Speaker Builder for 11" Dynaudio - two internal baffles - nothing removed - just a board clamped to front on smooth sealed trace
@Magnatar - I should have said "tiny" (like 1"x5" or 1.875" x 7") k-tubes have ~no gain . a mini klam with fairaly large gap like doggie tried on a Fostex BLH might make a nice match for Rosie types
that's Transylvania's "The Tube" on top.
@Magnatar - I should have said "tiny" (like 1"x5" or 1.875" x 7") k-tubes have ~no gain . a mini klam with fairaly large gap like doggie tried on a Fostex BLH might make a nice match for Rosie types
An externally hosted image should be here but it was not working when we last tested it.
that's Transylvania's "The Tube" on top.
Ultra-Fidelity vs Klam
one more thing - the regular Ultra Fidelity Karlson configuration (with strong enough driver) allows a punchy package without much box depth. 14" deep is enough for some couplers
rear lowpass choke generally need empirical tuning with know music tracks to subjectively get tight transient response. z- plots might help
one more thing - the regular Ultra Fidelity Karlson configuration (with strong enough driver) allows a punchy package without much box depth. 14" deep is enough for some couplers
rear lowpass choke generally need empirical tuning with know music tracks to subjectively get tight transient response. z- plots might help
I've been reading through these threads and find the comments really interesting. Especially the First few Threads and How Bad these cabinets sound.
Who ever built them Couldn't have done a Proper job on them or they used the Wrong Materials in Construction.
Plywood Doesn't do it.
I Originally built a pair of the Karlson Cabinets back in the 60's using Jenson Triaxial Speakers. Excellent Sound.
Now I have a pair made 3/4 Scale with some custom made 12 inch Coaxial speakers. These speakers have a Free Air Resonance of about 15 Hz.
Results, Even Better than the Jensons.
My Best comparison of them, was to "Bose 901" speakers and both these Karlsons beat them hands down in listening tests as well as some other acoustic measurements done at Simon Fraser University in Vancouver B.C.
Sorry this was MANY Years ago and I don't have those actual Test Results anymore.
But anyway, this is my 2 Cents worth.
Who ever built them Couldn't have done a Proper job on them or they used the Wrong Materials in Construction.
Plywood Doesn't do it.
I Originally built a pair of the Karlson Cabinets back in the 60's using Jenson Triaxial Speakers. Excellent Sound.
Now I have a pair made 3/4 Scale with some custom made 12 inch Coaxial speakers. These speakers have a Free Air Resonance of about 15 Hz.
Results, Even Better than the Jensons.
My Best comparison of them, was to "Bose 901" speakers and both these Karlsons beat them hands down in listening tests as well as some other acoustic measurements done at Simon Fraser University in Vancouver B.C.
Sorry this was MANY Years ago and I don't have those actual Test Results anymore.
But anyway, this is my 2 Cents worth.
I`ve build about 10 pairs of Karlson enclosures in my life.
Most of them in a incredible heavy and ridid construction - in a quality I have nowhere seen before until now (unless those of a buddy who has built a sandwich enclosure version where the inner/outer enclosures were completely decoupled through a 5cm! thick layer of sand. No chance to move that thing only one mm without removing the sand).
Plywood or not or whatever else kind of material You use for the cabinet, this has nothing to do with the nasty inherent resonances that this kind of enclosures do produce.
Putting a Signal Generator and Audio analyzer on my cabinets, there are No bad Resonant points on my cabinets.
The Outside dimension of the Origional plans I have are a cabinet thats:
33 inches high, 22 1/2 inches wide and 18 inches deep
Maybe there plans are different?
But anyway, to each his own.
I'm Very pleased with what I have.
The Outside dimension of the Origional plans I have are a cabinet thats:
33 inches high, 22 1/2 inches wide and 18 inches deep
Maybe there plans are different?
But anyway, to each his own.
I'm Very pleased with what I have.
I`m not talking about material resonances of the cabinet itself but those produced acoustically due to the various internal cavities and vents of the Karlson concept.
I have built Karlsons in all flavours - from the original dimensions to variations thereof to much smaller ones. I have experimented also with, I can`t remember how much, a lot of different drivers.
That`s fine and there is nothing to argue.
Once I liked Karlson´s too (and I admit it partly had also to do something with the unique and somehow "cool" appearance) - otherwise I wouldn`t have built them (BTW: it was very late when I posted yesterday, I recalculated in total 11 enclosures I have built completely by my own, not 10 pairs).
I agree that Karlson`s can sound very good on some music material like Rock but for more "demanding" (and my taste of music is manifold) they simply don`t satisfy me anymore.
12" Karlson
I apologize in advance, quite non-scientific comments to follow. Sometime in the mid 1950s, my dad made a Karlson enclosure for a 12" EV(?) woofer. Guys, driven by an 8w Stromberg-Carlson w/6BQ5 outputs, it always sounded really good and would consistently rattle the windows when requested. FF to 1998, I finally got the money & the time so I installed a (chinese) dual voice coil subwoofer w/ a rubber surround & a 300W (chinese) SW amp & put the box in a corner. The damned thing now blows away my mains, I have to keep the gain way down or we get Slammed every time an action movie comes on. The science of this box eludes me except I know that at least for subwoofer frequencies, it has the efficiency of a ported enclosure yet the accuracy of an infinite baffle. I also know the interior shelf items on the front of the driver have to have a gloss finish else the magic just ain't there.
I apologize in advance, quite non-scientific comments to follow. Sometime in the mid 1950s, my dad made a Karlson enclosure for a 12" EV(?) woofer. Guys, driven by an 8w Stromberg-Carlson w/6BQ5 outputs, it always sounded really good and would consistently rattle the windows when requested. FF to 1998, I finally got the money & the time so I installed a (chinese) dual voice coil subwoofer w/ a rubber surround & a 300W (chinese) SW amp & put the box in a corner. The damned thing now blows away my mains, I have to keep the gain way down or we get Slammed every time an action movie comes on. The science of this box eludes me except I know that at least for subwoofer frequencies, it has the efficiency of a ported enclosure yet the accuracy of an infinite baffle. I also know the interior shelf items on the front of the driver have to have a gloss finish else the magic just ain't there.
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