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K-402 in wood!

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Hello fellow members. I am looking forward to build a horn in wood with K-402's profile. A clone in wood. Are there any plans or does anyone know of its modified tractrix profile. It is not possible for me to see or hear one in person where I live so I need some help from you people :)

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it would be a lot easier to simply do a fiberglass mold or a clay model from the original for reproduction -

 

 

wood would only be for show purposes -

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Hello fellow members. I am looking forward to build a horn in wood with K-402's profile. A clone in wood. Are there any plans or does anyone know of its modified tractrix profile. It is not possible for me to see or hear one in person where I live so I need some help from you people :)

I was thinking about this subject all week

And I don't believe there are any real plans available

Then I thought about an Eliptrac version of the K402

Don't think Dave would do it but if he did I would buy a pair

Come on Dave how about it

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I can not do a mold or a clay model as I have no access to originals. Klipsch dealers here have no idea about a k402 horn. I don't think pro line has reached these shores. They don't even know much about heritage line... 

 

My v-tracs are in wood. My Khorn bassbins are in wood, my tapped horn is in wood. My old squawker was in fiberglass. Although it has to more to do with the profile of that horn, it is my least favourite and most coloured horn of all.

 

I am sad to hear there are no plans. I could't find anyone who made a clone over forums as well. I hope someone comes up with a plan. It is does not look like a complicated build once you have the dimensions. It looks like a bigger Bruce Edgar tractrix until the last few inches where it has a second flares outwards... Hard to guess from photos...

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"Are there any plans or does anyone know of its modified tractrix profile"

 

It is not a tractrix profile through most of its length.

 

" It looks like a bigger Bruce Edgar tractrix until the last few inches where it has a second flares outwards..."

 

As you can clearly see, its basic expansion is conical, only the round-over at the mouth looks like it might be tractrix.

 

Klipsch K402 021 (Large).JPG

2jubscala.jpg

CRW_2205.gif

Roy says there is a small amount of bow (or bulge) in what looks like the flat sides near the throat.

Edited by djk
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It is does not look like a complicated build once you have the dimensions.

 

 

These are large horns - and not "easy" to build, as you can see from the bottom photo that djk posted (i.e., my photo of one of my K-402/K-69-A assemblies the day they arrived at my abode in December 2007).

 

I'd recommend doing a bit more research on this design before saying "it's conical", or "it's a round-over mouth"--pat statements that are incorrect.  I've done my due diligence and I can say without a doubt that these are modified tractrix horns.  How are they modified?  Buy a pair from Klipsch and check them out yourself.  Roy Delgado (roy.delgado@klipsch.com) will take your order.  They're available for ordering.

 

These are by far the best sounding midrange-HF horns that I've ever heard.  I listen to them several hours every day and they, with a pair of Jubilee bass bins, form the basis of my "home remastering room".  Why these horns continue to generate so much interest and criticism is beyond me.  Buy a pair and listen to them-as I do.  You'll never be disappointed.

 

Horns are really for listening--not looking at: put a grill cover over the mouths like Kudret did if you cannot tolerate looking at polymer material.  The price of wooden K-402 horns would be thousands of US dollars per horn--trust me--and that is a low estimate.  These are large horns.

 

Chris

 

new Jub setup in garage.jpg

Edited by Chris A
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How are they modified?  Buy a pair from Klipsch and check them out yourself.  Roy Delgado (roy.delgado@klipsch.com) will take your order.  They're available for ordering.

 

As I have stated before, these are not being sold in my country and the dealer I talked to didn't even know about them! 

 

I can not import them from US either, because of their cost and size. We have certain limits at customs regarding size/weight and cost for people to import stuff. If the products price/weight are beyond them you can not import. You can not say, I am ok with the taxes, i will pay, get me my stuff. It will be considered a commercial transaction and you would need a company with proper permissions to do that. That is why I contacted the Klipsch distributor here but got that answer. So I can not buy a pair and see for myself dear Chris.

 

I know they are big horns, but they are not that big for me to be afraid of building. I love doing stuff myself. An 8 feet high tapped horn may be considered big, but I still built it out of mdf and enjoy it immensely. It weighs over 220pound but is incredibly rigid and sounds/feels wonderful.

 

This is no commercial approach either so I do not think I am harming anyone.

 

I'd recommend doing a bit more research on this design before saying "it's conical", or "it's a round-over mouth"--pat statements that are incorrect.  I've done my due diligence and I can say without a doubt that these are modified tractrix horns.

 

Yes that is what I think as well about the profile. That is why I was asking for help. Maybe I should write to Roy Delgado and ask for him directly for help. 

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I just wrote to Mr. Delgado for help, thank you for sharing his email with me.

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If Chief Bonehead can't help you (and I can't imagine that he can't...) then some approximation of the horn might be possible to build at home depending on your prototyping and fabricating abilities, and the materials that you have access to for fabricating.  Please PM me if Roy cannot help you due to your stated import restrictions. I'm assuming that those restrictions are for PRC--but I know that it could be other countries. 

 

I'm pretty sure that I'd avoid wood and wood products if I approached a DIY horn since the internal shape is not actually flat, and the horn profile cutting would require a CNC router of fairly spectacular proportions (x-y) and tool travel depth to hog out from stacked-and-glued MDF or other type of wood products, i.e., the processes that Dave uses to fabricate his ellipsoid--tractrix MDF horns. 

 

Please remember that none of these approaches would be easy and would likely not duplicate the performance of a K-402, but you could certainly get close to its performance. 

 

Chris

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I can't help you with the profile, but what fabrication method were you planning to use? 1/20 of an inch is a difficult tolerance to hold in wood designs this large...

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"I've done my due diligence and I can say without a doubt that these are modified tractrix horns."

 

Blind, are we?

 

My vision isn't the best, but I can SEE that the initial expansion is not tractrix.

Edited by djk

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Yes.

 

[EDIT: ...if you are thinking that the throat is the "initial area" like on all other "expansion profiles". 

 

For tractrix, it's the mouth that is the initial area.  That's how the curve is constructed--from the mouth.]

 

The inventor says "modified tractrix" and he's not wrong.  To assert that it isn't modified tractrix is actually something that looks a bit affected since the inventor's description is accurate. 

 

I'll go with the inventor's description, since he's clearly a good guy and he invented my loudspeakers...you didn't.  ;)   Plus I think he's pretty smart too.

 

Chris

Edited by Chris A

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If I were to try this . . .

I'd get a big piece of paper and mark off the mouth dimensions, and the location of the driver, which is going to have a 2 inch diameter, such and such inches back.

Then draw a tractrix curve starting at the wide horizontal mouth and draw the curve until it points to the side of the driver. Then a straight line to the driver. Then start at the narrower vertical and do the same.

You'll wind up with a tractix mouth transitioning to the straight back section which will be conical.

You'll have to fudge a bit to make the final transition at the throat from a rectangular to the circular mouth.

It will be a bear to bend wood for the mouth end.

My thought is that great precision is not necessary.

WMcD

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If I were to try this . . .

I'd get a big piece of paper and mark off the mouth dimensions, and the location of the driver, which is going to have a 2 inch diameter, such and such inches back.

Then draw a tractrix curve starting at the wide horizontal mouth and draw the curve until it points to the side of the driver. Then a straight line to the driver. Then start at the narrower vertical and do the same.

You'll wind up with a tractix mouth transitioning to the straight back section which will be conical.

You'll have to fudge a bit to make the final transition at the throat from a rectangular to the circular mouth.

It will be a bear to bend wood for the mouth end.

My thought is that great precision is not necessary.

WMcD

I think you are making it sound too easy.

 

First, I believe the tractrix is not referring to the flare of the sides but rather to the form the expansion of the cross-sectional area.

Second, the term, "modified", I believe refers to the area of expansion as actually being a composite of three functions (of the exapansion of the cross-sectional area). One of these functions is tractrix and another is conical. the third has not been explicitly defined (to my knowledge at least).

 

There are some unknowns about the transition between the functions.

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NOT conical...straight sided.  There is a difference.  Read your Olson or Beranek.

 

It will be a bear to bend wood for the mouth end.

 

Yes.

 

My thought is that great precision is not necessary.

 

At the mouth end - yes.  At the throat--you're dead wrong.  On the "straight-sided" (not actually straight) areas, you need to hold tolerance. 

 

You need an accuracy similar to what Mike Bentz said, and that's pretty tight for wood unless you're using CNC to hold tolerance--and your wood better be dimensionally stable, i.e., not full of moisture.

 

I don't recommend wood as the base material for this type of horn.

Edited by Chris A
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I think one made out of clear plexi would be awesome.

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If I were to try this . . .

I'd get a big piece of paper and mark off the mouth dimensions, and the location of the driver, which is going to have a 2 inch diameter, such and such inches back.

Then draw a tractrix curve starting at the wide horizontal mouth and draw the curve until it points to the side of the driver. Then a straight line to the driver. Then start at the narrower vertical and do the same.

You'll wind up with a tractix mouth transitioning to the straight back section which will be conical.

You'll have to fudge a bit to make the final transition at the throat from a rectangular to the circular mouth.

It will be a bear to bend wood for the mouth end.

My thought is that great precision is not necessary.

WMcD

Bendable plywood?

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I use a particular size of large socket with a 2" OD (1 7/16" socket) to center up the compression drivers with the horn mouths, and shimmed to a few thousandths of an inch of being concentric at the 2" ID snout on the TAD driver, and I use modeling clay to seal any gaps at that interface.

 

Before I did this fine adjustment of the driver-to-horn positioning, I could see FR and phase irregularities in the REW plots at the driver-horn interface frequency. 

 

That little exercise made me a believer of being careful about the throat end of compression driver/horn interfaces, and the importance of holding tolerances at the throat of the horn itself.

 

Chris

Edited by Chris A
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It is does not look like a complicated build once you have the dimensions.

 

 

These are large horns - and not "easy" to build, as you can see from the bottom photo that djk posted (i.e., my photo of one of my K-402/K-69-A assemblies the day they arrived at my abode in December 2007).

 

I'd recommend doing a bit more research on this design before saying "it's conical", or "it's a round-over mouth"--pat statements that are incorrect.  I've done my due diligence and I can say without a doubt that these are modified tractrix horns.  How are they modified?  Buy a pair from Klipsch and check them out yourself.  Roy Delgado (roy.delgado@klipsch.com) will take your order.  They're available for ordering.

 

These are by far the best sounding midrange-HF horns that I've ever heard.  I listen to them several hours every day and they, with a pair of Jubilee bass bins, form the basis of my "home remastering room".  Why these horns continue to generate so much interest and criticism is beyond me.  Buy a pair and listen to them-as I do.  You'll never be disappointed.

 

Horns are really for listening--not looking at: put a grill cover over the mouths like Kudret did if you cannot tolerate looking at polymer material.  The price of wooden K-402 horns would be thousands of US dollars per horn--trust me--and that is a low estimate.  These are large horns.

 

Chris

 

new Jub setup in garage.jpg

 

How about making them with a 3D printer?

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