lets discuss Karlson

[freddi]

nothing has much worse reputation - they're considered by some to do nothing (good). I've heard the things bad, and sometimes very good. Cone deflection can be very low imo for high outout - especially on transients where reflex can get into trouble. Relatively strong motors were/are used.

John Karlson's invention list of 1950 lists an acoustic transducer with load-matching and controlled reverbration properties.

Karlson's originals ran 30-40 cubic inches rear chamber volume per square inch of cone and front chamber space about 1/2 that of the rear chamber. Smaller ratio coupler went to semi-resistive vents, perhaps to give better subjective damping on transients as those were the days of mix and match. (Karlson's "x15" system used 3/4" diameter d-Q-ing holes flanking a port)

Karlson - coupler, unlike horn, have certain size constraints to work and no real midrange gain other than ripple or dispersion effects.

there must be a few builders in the entire world besides one commercial K15 built in France.

are there any K-experimenters who wish to share lore, data, recipes, favorite drivers?

k-tube waveguides sound nice. I don't know what might be done for a K-midrange coupler.


Freddy

[jamikl]

Hi Freddi. I have some interest in these. If you see my post in the fullrange thread it discusses - shows- something similar. It is also similar to what my gut feeling is the way it should be done.

Recently I cut a slot, roughly exponential in a 7 inch length of cardboard tube and attached it pretty roughly to s cone tweeter. It was tube that plastic clingfilm is wrapped around. You could certainly hear where the slot began to work.

I think it would be great if MJK had the time or the inclination to look at these as I feel they are as yet untapped. I think Scottmoose feels the same way.
jamikl

[freddi]

hi jamikl - maybe we can bribe Martin ? :^)

Zintz's Transylvania tube was cool for ~2Khz up and had 2 degree downwards taper. I made straight 5.3-5.5" pvc tubes with half-ellipse which work well before seeing a real Transylvania "The Tube"

CN is looking at slot inductance & capacitance to solve Poppe's work but might not ever share data (?)

heres CN's take a few years back on K15 (UF = "Ultra-Fidelity)

--" Fh behaves different for the UF compared to a horn.

Fhm = factor * EBP

For a horn the factor is 2. This is why you can't get a horn to have an extended high end.
The UF 's advantage is that it is essentially "open" at MF and has extended band width comparred
to a horn.

If you make the UF less "open" the upper MF reduces. If you tighten it enough, the Fh is severly
restricted, much like a bandpass.

***, says the design of the box is a 4 deg of freedom system.

The tapered slot requires complex mathematics to represent.

To understand the UF remember the horn of the Altec is essentially "open" to the enviornment
with some box reverb.BTW:without reverb, electronic or mechanically induced to a critical
minimum level, the reproduced sound will not sound real.

Now the low end. The port output is driving the Karlson coupler. You don't want high frequency tube resonances
coloring the sound. Therefor no tubes. Starting with the backwave, a low pass filter, and padding to kill a lot
of MF/HF going to the port.

The port mass is set to provide LF drive to the coupler. The mass loading of the coupler lowers
the f3 while the coupler provides the gain. The front shelf blocks significant MF/HF from the top chamber.

The rear volume is made small because a sealed coupler at LF loads similar to a horn.

Likewise the ported volume can be lower like ported horns.

Remember, you can't be an expert on the UF without building and testing them.
Same goes for horns, sealed and ported boxes etc. ... "


Freddy

[jamikl]

freddi, if you turn your Karlson cabs. around so that they face the wall, close enough for the slot to "feel " the wall what do they sound like. Is it muffled bass or does it work well. Thinking of mass loading the slot by the wall or the floor.
jamikl

[freddi]

hi jamikl - be interesting to see effects and take input Z.

I've not done it due to 1/2" sheetrock walls plus have piles of horns, etc in way right now. Maybe a K15 owner with good walls can report.

freddy

[c2cthomas]

Hi freddi!

I've been reading your input over on Magnetar's thread about his OB's and got interested about "the Tube" (k-slot tweeter).

I'm working something up that will be an OB - but not as big as Magnetar's (can't afford THAT). Chops has an interesting prototype over on his thread but it uses a very big horn that presents a space problem for me.

I want to toss together one of your "K-Tubes" (do you have a name that you prefer to have them called?) for HF and intend to use the B&C DE10-8. PE has the Eminence APT-3 adapters as well but this is where things start to get a little fuzzy for me. How to mate the driver plus adapter to the K-slot. Maybe when I have the parts I will have a BFO (Brilliant Flash of the Obvious ) and thing will seem clear - buuuuttt you have already been there - done that - and thus the question. I have a Dremel set and understand your drawing posted at Magnetar's site - so no problem making the tube - I'm just unclear on how to assemble the parts. I'll be glad to post some photo's as I go along if it would serve to help others out.

[Ron E]

Freddi,

Do you have anything objective that backs up your performance claims? I have certainly never seen anything which substantiates any claim of the "Kult of K".

[Magnetar]

Originally posted by Ron E
Freddi,

I have certainly never seen anything which substantiates any claim of the "Kult of K".

LOL , there is a Kult, and we got your number.




Kult

[freddi]

2=tone Beta 15cx swapped between k15 and 'equivalent' reflex
http://img474.imageshack.us/img474/7707/dop151wm4.jpg


50Hz 20vrms k vs Yorkville usc1 pipehorn
http://img54.imageshack.us/img54/4400/k18f20vrmsug3.jpg

[Ron E]

that's proof? The whole point of the K slot is to make flat frequency response, by analogy to a steam whistle that makes noise rather than a tone when an exponential slot is cut in it.

For your distortion plots to be any kind of proof you need drawings and /or photos of the compared systems, frequency response and distortion curves and twin tone plots at multiple frequencies. Then some discussion of the results. That would come closer to "proof".

I'm sure if you made a down firing sub closely coupled to the floor you would see a pretty significant "measured" distortion reduction due to the cavity.