Back Loaded Horns

[Helmuth]

Thread split from Jean Michel on LeCleac'h horns
__________________________________________________ _____________

Originally Posted by Lynn Olson

I find it interesting that I've always liked the bass of Klipschorns, Belle Klipsch, and La Scalas, yet I know the frequency response of these folded horns is terrible, with 10~20 dB holes in the response, especially where they struggle to meet the bottom of the modest-sized midhorn. .

Hi Lynn,


10db holes?

here a 2way backloaded horn January 2010. You can also see that on the ripple at 200Hz. Topic Project presentation Horn Almighty


Here the system in stereo measured on listening position it was in fact reasonable flat 30hz -15dB. Only the mid range seemed to change constantly, some day it sounded great and a other day it was not so good any more.

[Helmuth]

Lynn I found a very good candidate for frontloaded sub.

18sound Here the simulation conical horn. With bas-reflex loading I think 40Hz is possible..



1 PHI response


0,5 PHI = corner position.



To give a idea very good loading and there for nice flat response

[Helmuth]

My first horn project data september 2000. The chipwood one was the proto type. (It sounded better the the folded one more sub bass.)


Here the active 2 way titanium horn with a big experiment next to it.


And here the plans of the la scala to show how to fold the horn. 1/4 lambda = about 1 meter! very short, good loading down to 86Hz



Horn loaded sub gives transparent subbas.

[jzagaja]

Lynn, have you seen/heard Cogent or Goto bass compression driver? This year with Autotech I'm going to release such a driver together with dedicated bass horn.

[3GGG]

Would you care to explain further:-)
QUOTE=jzagaja;2450163]Lynn, have you seen/heard Cogent or Goto bass compression driver? This year with Autotech I'm going to release such a driver together with dedicated bass horn.[/QUOTE]

[jzagaja]

Motor assembly will be designed in UK and rest parts in Denmark. Autotech will supply bass horn. Independently we will try to make our own prototypes. New machine for coil winding expected in May.

[Lynn Olson]

Originally Posted by jzagaja

Lynn, have you seen/heard Cogent or Goto bass compression driver? This year with Autotech I'm going to release such a driver together with dedicated bass horn.

Hmm ... not really. The few times I've heard Cogent at the RMAF it was a work-in-progress, so I couldn't really assess the sound at all. Combine the wacky acoustics of a hifi show with a loudspeaker that is still in development, and it's hard to tell what the final product in a customer's home is meant to sound like. From my limited exposure, I do like the sound of field-coil drivers, but I'm not sure they sound any better (just different) than Alnico. The Goto's are astronomically expensive, far out of the range of any project I would attempt.

I encourage your project - the typical high-end bass isn't very good. At every hifi show, it's an array of 8, 10, or 12-inch drivers. Over and over and over again. I'm getting very tired of the flat tonal quality of these things, which is not a good match to high-performance mids and HF drivers (such as compression drivers, ribbons, or electrostats). Dipoles help, but they typically require a lot of equalization if the drivers are working over a 1-decade frequency range, which makes them unsuitable for triode amplifiers.

Helmuth, thank you for your kind suggestions. How big is that straight horn, anyway? I suspect it's too large for my living room, and I'm not about to spend $30,000 to convert my unfinished basement to a living space. The curved or folded horns look more possible - something about the size of the La Scala, or maybe the vented-rear-chamber variant somebody came up with a few years ago. I'd like to credit the author of that variation, but I don't recall his name at the moment. Just wondering if there is a modern version (not using the Klipsch parameters or folding scheme) that covers the 70~700 Hz range reasonably well - the La Scala doesn't really go up to 700 Hz, more like 350~400 Hz at most.

[Helmuth]

Originally Posted by Lynn Olson

Helmuth, thank you for your kind suggestions. How big is that straight horn, anyway? I suspect it's too large for my living room, and I'm not about to spend $30,000 to convert my unfinished basement to a living space. The curved or folded horns look more possible - something about the size of the La Scala, or maybe the vented-rear-chamber variant somebody came up with a few years ago.

Hi linn I am European so I calculate metric.

The la scala is about 295litre.

My simulation is 254 litre it would become the same size as the la scala.

Personaly I would say forget the form of the la scala. and fold it something like this one. This drawing is a cube shape I would make it taler and like this one woofer cone facing the top of the box. And a BR opening in the closed volume.

[Helmuth]

Impedance (at 1 phi) of the woofer BR tuning of 45 Hz shout be possible. Then it would out perform the klipschhorn.

15nmb420

[Helmuth]

Originally Posted by Lynn Olson

Just wondering if there is a modern version (not using the Klipsch parameters or folding scheme) that covers the 70~700 Hz range reasonably well - the La Scala doesn't really go up to 700 Hz, more like 350~400 Hz at most.

To cover up to 700Hz with a horn of 1.6 meter. It would colour. Use it as sub up to 200-300Hz.

Then XO to the BMS 4591


And a super tweeter.
like this one from P-audio and it it has become a improved la scala.
http://www.paudiothailand.com/pdf/products/PHT-409.pdf