in practice there's no HF rolloff - they work very well with coaxial and fullrange. I'd like to know why I've seen a ~36Hz null with a nearfield mic at the center or bottom of the cone - K15 seems to handle more power at 36 than a reflex = to its back chamber volume and same apparent tuning.
the nearcone null seems to come in around 1/2 octave below fb -- there is legend that K's damp cone excursion below cutoff
K15
18" in a K15 size coupler without a front or rear shelf - fb~45 - this was outdoors so maybe why more pronounced -?
the nearcone null seems to come in around 1/2 octave below fb -- there is legend that K's damp cone excursion below cutoff
K15
An externally hosted image should be here but it was not working when we last tested it.
18" in a K15 size coupler without a front or rear shelf - fb~45 - this was outdoors so maybe why more pronounced -?
An externally hosted image should be here but it was not working when we last tested it.
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You are welcome. The second cone motion null circa 160 Hz is consistent with observations according to IG81. I believe it is similar to the double tuning you get in a dual chamber reflex. There are really three chambers here, the front being open with the K aperture. If you are interested in the model, the details of how I did it in Akabak are in the Karlson thread here http://www.diyaudio.com/forums/full-range/213594-karlson-10.html#post3528706 The response past 1 kHz falls of due to the bandpass nature of the K15 - it really is a hybrid big vent reflex with a dual chamber reflex in the back, with some tapped horn action going on on too. However, in reality, a lot of direct radiation from the front of the cone makes it out past the K aperture, so if you are using a smaller dia full range, you will still get pretty good highs. The natural falloff of the Delta Pro 15A is around 2 kHz anyway so this really needs a CD and K tube to fill out the top end.
RCA-Fan's X15 size K-coupler with perpendicular board above baffle and 2" gap transflex style vent - no rear lowpass choke
Acoustic Control's X15 size "115BK" K-coupler which had a 2" gap between its diagonal baffle and top - plus a reflector panel with ~27 sq. in. vent
8 cubic foot coupler with old EV SP15B weak motor (Qts>1.2IIRC) and high fs - there's no front nor rear shelf - just two 4.5" holes in the lower reflector panel
reconed 604 in K15 with 30.5 sq. in. vent
high aspect K18 - no front shelf - but has a rear lowpass shelf
An externally hosted image should be here but it was not working when we last tested it.
Acoustic Control's X15 size "115BK" K-coupler which had a 2" gap between its diagonal baffle and top - plus a reflector panel with ~27 sq. in. vent
An externally hosted image should be here but it was not working when we last tested it.
8 cubic foot coupler with old EV SP15B weak motor (Qts>1.2IIRC) and high fs - there's no front nor rear shelf - just two 4.5" holes in the lower reflector panel
An externally hosted image should be here but it was not working when we last tested it.
reconed 604 in K15 with 30.5 sq. in. vent
An externally hosted image should be here but it was not working when we last tested it.
high aspect K18 - no front shelf - but has a rear lowpass shelf
An externally hosted image should be here but it was not working when we last tested it.
nice ad http://img208.imageshack.us/img208/332/axthekarlson.jpg
An externally hosted image should be here but it was not working when we last tested it.
A mahogany K15 for $118? Probably a lot of money in 1955 but a down right steal today. Did Karlson typically use coax's as I don't see a tweeter on his typical speakers? Or were people happy to hear up to 5 kHz?
An online inflation calculator says this is equivalent to $128 in today's dollars. I guess that sounds about right.
An online inflation calculator says this is equivalent to $128 in today's dollars. I guess that sounds about right.
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some of the old coax used in K15 can demand a lot of money - I'd go relatively cheap with a new-old-stock P-Audio 15CHA - the protruding horn version is gone and this one is probably deleted -
for the Beta 12LTA lover, I'd think that would play well in K15 - augment with a short K-tube helper tweeter
P AUDIO_BM15CXA $270 including the BMD440 compression driver
for the Beta 12LTA lover, I'd think that would play well in K15 - augment with a short K-tube helper tweeter
P AUDIO_BM15CXA $270 including the BMD440 compression driver
An externally hosted image should be here but it was not working when we last tested it.
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X- how tough is it for you to model a Klam?
here's a commercial product - Alan Weiss' "Patio" speaker - IIRC, one of mine is now loaded with a BetsyK- since the speaker sits back pretty far, there can be some "sea-shell" artifacts at higher frequencies up close - those aren't noticed at a distance. A coaxial with K-tube extended to the main aperture plane pretty much removes such stuff. Karlson apparently at one time had the military test a klam.
my pair
picture from ad
rough sketch http://img685.imageshack.us/img685/4966/smallklam.jpg
here's my klam15 with Eminence C15CX / generic network playing with a K-tube jammed down the coax horn - in practice with a screened dustcap like the Beta series cs, the tube would be beveled and set in with a glue. Its not quite right but would work for PA - Karlson's Magna-clam/AP100 was 45" long
http://www.youtube.com/watch?v=mupb8X6iZ6I
a good klam10 or klam12 would be fun
here's a commercial product - Alan Weiss' "Patio" speaker - IIRC, one of mine is now loaded with a BetsyK- since the speaker sits back pretty far, there can be some "sea-shell" artifacts at higher frequencies up close - those aren't noticed at a distance. A coaxial with K-tube extended to the main aperture plane pretty much removes such stuff. Karlson apparently at one time had the military test a klam.
my pair
An externally hosted image should be here but it was not working when we last tested it.
picture from ad
rough sketch http://img685.imageshack.us/img685/4966/smallklam.jpg
here's my klam15 with Eminence C15CX / generic network playing with a K-tube jammed down the coax horn - in practice with a screened dustcap like the Beta series cs, the tube would be beveled and set in with a glue. Its not quite right but would work for PA - Karlson's Magna-clam/AP100 was 45" long
http://www.youtube.com/watch?v=mupb8X6iZ6I
a good klam10 or klam12 would be fun
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Freddi,
Them Klam should not be too hard to model, I have to put it in the queue as there are too many designs starting to stack up in my brain and need simulating. My latest is pretty simple to implement but harder because I am new to it: open baffle dipoles and multiways with cross-overs. So that I understand the Klam, it is a sealed box right? Which 8 in driver do you want me to run?
Them Klam should not be too hard to model, I have to put it in the queue as there are too many designs starting to stack up in my brain and need simulating. My latest is pretty simple to implement but harder because I am new to it: open baffle dipoles and multiways with cross-overs. So that I understand the Klam, it is a sealed box right? Which 8 in driver do you want me to run?
Karlson's klams were vented. With heavy signals sealed is good. No hurry to model one. When you do, make a 10" model with Beta 10cx - I've got a klam10 loaded with B10cx but the builder went by a radius spec rather than the finished dimension and its aperture is kinda choked - probably introduces extra unwanted reflections - that said, it sounds pretty good with the compression driver running hot
here's a klam 8 playing outside - it could go louder - I had it loaded with a Sammi 8" fullrange - it sounded reasonably loud 150 feet away and filled a large area
https://www.youtube.com/watch?v=znfE7hjQ40o
klam 10 loaded with B102
it should have looked like Carl Neuser's original
notes from which mine were made
here's a klam 8 playing outside - it could go louder - I had it loaded with a Sammi 8" fullrange - it sounded reasonably loud 150 feet away and filled a large area
https://www.youtube.com/watch?v=znfE7hjQ40o
klam 10 loaded with B102
An externally hosted image should be here but it was not working when we last tested it.
it should have looked like Carl Neuser's original
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
notes from which mine were made
An externally hosted image should be here but it was not working when we last tested it.
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I do not know what the preferred orientation of a Klam is with respect to mounting and listening position. Is the K aperture supposed to be vertical like the K15 or Karlsonator? I see a lot of pictures with it mounted with the back horizontal and the K aperture at a 30 deg or so angle. Need to know this to model it relative to the room walls and floor.
the clam/"klam" projectors typically were positioned high - either at the ceiling as in a Radio City Music Hall install, or sold with tripods. To my limited knowledge, Karlson's klams were series vented.
I believe Jess Oliver's "Magna-Clam" was about the same speaker as made under Karlson Reseach as an AP100. It probably used an Altec 421-8 plus compression driver on K-tube. I'd like to find a bigger picture of this ad.
Karlson's APX as the Oliver Phase III (loaded with a 10" alnico magnet guitar speaker)
I believe Jess Oliver's "Magna-Clam" was about the same speaker as made under Karlson Reseach as an AP100. It probably used an Altec 421-8 plus compression driver on K-tube. I'd like to find a bigger picture of this ad.
An externally hosted image should be here but it was not working when we last tested it.
Karlson's APX as the Oliver Phase III (loaded with a 10" alnico magnet guitar speaker)
An externally hosted image should be here but it was not working when we last tested it.
Mike Bates made a series vented 15" klam used on the floor as a midbass unit along with various mid and tweeter arrangements - he reported it more effective in use than midbass horns - imageshack has lost my pictures of "Rosie" - but here's a sealed rear chamber klam 18 I made from one sheet of playwood. The initial slot gap width had a lot of influence on its subjective presentation. I'm not sure if there's any advantage to a series vented klam on the floor vs K15 type other than lowering height and Metro System's T15 subwoofer is as low as my klam below
and here is Metro's series vented T15
An externally hosted image should be here but it was not working when we last tested it.
and here is Metro's series vented T15
An externally hosted image should be here but it was not working when we last tested it.
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K15 with Beta 12CX (0.636 Qts)
Freddi,
It turns out that your dusty old Beta 12CX with the mis-spec'd Qts appears to really do well in a K15 scaled up just a bit is size to 1.27X (19/15). It rocks with a 100 dB sensitivity and nice even response. Check out the sims, all with speaker 60 in away from back wall and measurements at 1 m with 1 watt input.
- Freq response at 1m
- Impedance
- Cone Displacement
- Impulse Response
- Freq response at 5m
- Polar plot of directivity for 60 Hz, 500 Hz, 1000 Hz at 1m
This driver looks like it was made for the K15 scaled up - very nice set of plots.
This thing will tear your face off with 50 watts input.
Freddi,
It turns out that your dusty old Beta 12CX with the mis-spec'd Qts appears to really do well in a K15 scaled up just a bit is size to 1.27X (19/15). It rocks with a 100 dB sensitivity and nice even response. Check out the sims, all with speaker 60 in away from back wall and measurements at 1 m with 1 watt input.
- Freq response at 1m
- Impedance
- Cone Displacement
- Impulse Response
- Freq response at 5m
- Polar plot of directivity for 60 Hz, 500 Hz, 1000 Hz at 1m
This driver looks like it was made for the K15 scaled up - very nice set of plots.
This thing will tear your face off with 50 watts input.
Attachments
hi X - that's just about a Gauss 5181 K18 - one early ad showed a much different aperture - perhaps for a different 18 - it opened faster and was more an inverted "V" shape. A year or so ago I got a Karlson brochure which showed that John Karlson offered a K18
one time I had one of those Beta 12cx in an X15 copy and vent opened up - was playing a Kudo drum - despite the higher cutoff, the drum transient was startling - and I was expecting the cone to break - but it didn't move much more than 1/8" peak to peak - this would have destroyed something like a fullrange in a reflex or blh.
seems like a K"13 or 14" would just about work strong if not low with Beta 12cx and 12LTA
here's an old and improperly smoothed graph of 3 coaxial laying on a pillow pointing up with a mic overhead - the old Beta 10cx (it was changed some years ago to present form), Beta 12cx and a Beyma 12cx for rough comparison of extension and output.
An externally hosted image should be here but it was not working when we last tested it.
one time I had one of those Beta 12cx in an X15 copy and vent opened up - was playing a Kudo drum - despite the higher cutoff, the drum transient was startling - and I was expecting the cone to break - but it didn't move much more than 1/8" peak to peak - this would have destroyed something like a fullrange in a reflex or blh.
seems like a K"13 or 14" would just about work strong if not low with Beta 12cx and 12LTA
here's an old and improperly smoothed graph of 3 coaxial laying on a pillow pointing up with a mic overhead - the old Beta 10cx (it was changed some years ago to present form), Beta 12cx and a Beyma 12cx for rough comparison of extension and output.
An externally hosted image should be here but it was not working when we last tested it.
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