Klason & Strange, folded basshorn, acient design ?

[Empee]

Hi all,


Anyone got any experience with this old design ?

The stand (the triangle) is actually part of the horn,
it stands in front of the hole in the bottomplate.

It's supposed to go from 30Hz up to 300Hz.



Cheers,

Empee

[Rudolf]

You might look at the german audiotreff forum and search (Suche) in the first 4 subforums for "Klason". I found a lot of information there.

[AKN]

Hi Empee,

Speaker from the Swedish magazine “Radio & Television” (“Ljud och Bild” today)
That one you displayed is the first in a series of three for 10" driver. Later came two newer versions for 12" driver, one smaller (RT2)and one in the same size as the first one. I have built the bigger of the latest called RT3.
Unfortunately it got destroyed about 20 years ago when a radiator started to leak water.

Back then I was very impressed by the sound, the usual horn benefits was there. Bass extension well down to 30Hz.

I do have the plans somewhere......

[Empee]

Hello Rudolf and 4fun,


Thank you both very much for your replies.

I searched "audiotreff" and found some usefull graphs!
makes me want to build this thing!!


Hey,
you say there were "new versions" ?
somehow improved I guess, and in different sizes aswell ??

I hope you can locate these plans, am very curious !!


cheers,

Empee

[AKN]

Hi Empee,

I think the first RT1 (called that then the later ones came out) was designed in 1974-75).

you say there were "new versions"
somehow improved I guess, and in different sizes aswell ??

Yep, two newer versions in 1978.
RT2 that was same size as the old RT1 but 12" driver, very simular but with some improvements.
RT3 little smaller (40Hz), more easy to build, again 12" driver.

From this it's obvious that i was wrong about RT2 and RT3 in last post, RT2 is the larger one. Sorry about that.

I will dig in the archives to find the old articles.

[AKN]

Hi,

No luck yet finding the articles.
I will ask a friend who I now has them, may take a few days more.....

[Empee]

Thank you very much for searching,

For sure I'm gonna build one.
If only for the test with a lot of scrap-wood I got left.

What driver did you use back then ?


I know the recommended driver is an Isophon 225 alu,
but will a different driver do ?


Cheers,

Empee

[Rudolf]

Originally posted by Empee
I know the recommended driver is an Isophon 225 alu,
but will a different driver do ?

Monacor SP 250KE and Seas wd 255 (discontinued) were recommended.

[AKN]

Hi,

Originally posted by Empee

What driver did you use back then ?

I did try a few, of those I remember:
Gamma LA-1231 (still available)
Philips AD12100HP8
H||H B12L

The "Gamma" being the best performer at the time, although today new choices are available of course.

Little info about the RT2 from memory:
Compared to your drawing, driver is mounted the other way around with back chamber facing inwards. Triangle enclosed and part of the back chamber.
Dimensions HxWxD/mm:~500x1200x600
I will get the articles on Monday, I'll post the designs then.

[AKN]

Hi Empee,

Got the magazines today.

Just to show the RT2 design:



Mail me and I send the whole article, in Swedish but many pics and complete plans.