Tractrix DIY

[Hoerninger]

Yesterday I visited a carpenter and I was (again) astonished about their modern skills and abilities. I gave him the idea and some formulas and he used his computer with Autocad (I presume). The computer will control his machines. He gave me this drawings and they will give you an idea what will be done.

May be you like it here.

You may wonder what is this about. I'm teacher in a school and I was asked to make a "Projekt-Kurs" about horn loudspeakers. (The theme was not discussable). So I have tried to teach the pupils some historical aspects - so obviously I had to mention JBL - and I have given them a practical try.
___________
Regards
Peter

[hapy._.face]

I gave him the idea and some formulas and he used his computer with Autocad (I presume). The computer will control his machines. He gave me this drawings and they will give you an idea what will be done.


Yep. Pretty cool.

http://en.wikipedia.org/wiki/CNC

Keep us posted. I'd like to see how it all turns out!

[Mr. Widget]

Here is a link to a series of pics showing the machining of a tractrix horn much like your drawing. They are from one of our members ikecarumba.

http://homepage.mac.com/ikecarumba/PhotoAlbum28.html


Widget

[L100t Owner]

Here is a link to a series of pics showing the machining of a tractrix horn much like your drawing. They are from one of our members ikecarumba.

http://homepage.mac.com/ikecarumba/PhotoAlbum28.html


Widget

Try this:

http://www.volvotreter.de/

[OLDGEN]

Try this:

http://www.volvotreter.de/

super! i want horn!!!:banghead:

[Hoerninger]

Many thanks for the links.

Here is a link to a series of pics showing the machining of a tractrix horn much like your drawing. They are from one of our members ikecarumba. When I looked at the beautiful pictures it suddenly made "click":
- I like the optic of wooden horns
- I've read about Smith-horn in LH forum
- and now I have "my" carpenter.
I simply put Smith horns on my ToDo list. .. some ideas last a bit longer, I had no plan so far.


Keep us posted. I'd like to see how it all turns out! Until now the bass horns are closed but not finished. They are for 15 inch low Q speakers. There is a lot of work left to be done. Here is a first impression, the tractrix enclosure fits the width of the big horn.
___________
Regards
Peter

[yggdrasil]

I have done some work on Tractrix horns - http://audioheritage.org/vbulletin/showthread.php?t=8363

A couple of weeks ago I solved the problems at hand with bi-radial/sectoral tractrix horns. I have not yet measured off axis in any way (off axis).

[Hoerninger]

I have done some work on Tractrix horns - http://audioheritage.org/vbulletin/showthread.php?t=8363

A couple of weeks ago I solved the problems at hand with bi-radial/sectoral tractrix horns. I have not yet measured off axis in any way (off axis). Hej,

with great interest I've followed your link. For a moment I was inclined to change my concept.

IMHO your appraoch combining a radilal horn with a traxtrix shape is ingenious.:applaud:

Compared to a pure tractrix horn there is a better control of horizontal sound distribution.
Compared to a Smith horn the vertical distribution is controlled by the tractrix guidance instead of by diffraction. This may result in the same wavefront but perhaps in a more natural sound.
(In fact I didn't change my concept because it would be too dififficult for the pupils. I let them mainly work with glue and a accu screwdriver.)

Could you please answer the following questions, Johnny?
1. Do you have already some test results?
2. Could you please explain the vertical control of your jig and the tool your drilling machine is driving?
__________
Regards
Peter

[yggdrasil]

Hi Peter

I have not done extensive measuring. Will be back with more measurements later on. Have to finish a few amps first.

Vertical control and horisontal control is done with a long threaded steel, see attached pictures.

The arc is controlled by bolting the jig at one end.

Attached to the drill is an iron from my router set.

[green heron]

http://im1.shutterfly.com/media/47a0dc36b3127ccef9375044e58100000030O00AcM27FizaNm IPbz4K/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

Inspired by volvotreter, I just built my first tractrix horn (320 Hz) out of baltic birch. It turned out better than I expected. It was my first lathe project too (I'm sure a lot of you fall into that category).

I detailed every step in a blog (http://diyfirefly.blogspot.com):

http://diyfirefly.blogspot.com

[green heron]

http://im1.shutterfly.com/media/47a0dc36b3127ccef9375044e58100000030O00AcM27FizaNm IPbz4K/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

Inspired by volvotreter, I just built my first tractrix horn (320 Hz) out of baltic birch. It turned out better than I expected. It was my first lathe project too (I'm sure a lot of you fall into that category).

I detailed every step in a blog (http://diyfirefly.blogspot.com):

http://diyfirefly.blogspot.com