2" tractrix horn, any interest?

Care to share the Bulgarian contact? I ma sick of the fiberglass work and will rather give it to someone local.

SouthwestCNC wrote: Elliot Thompson wrote: Using unconventional methods to attain a general idea on what a concept can become is the art of a creative mind. Usually one 300 Hz horn per column should get the job done. It is nice to see someone focusing on midrange for once than the never ending threads on bass and treble. Needs to be done with the aim Good vocal reproduction in the mids with FLH'S instead of bph With james secker and teunos help, thanks guys.

As you never had a 300 Hz horn before, you really do not need more than one per column. You can look at the vintage Altec Voice Of The Theatre to get an idea how well a 300 Hz horn will keep up to an enclosure of such a magnitude. Bear in mind, the compression drivers used in that era were the weakest link…not the 300 Hz horn.

 

Mating a BMS compression driver to a 300 Hz horn will yield excellent results at a fraction of the power you are currently using with modern-day miniature compression horns.

 

Best Regards,

I recall mounting a modern day 3 inch full-range speaker on a 300 Hz horn from the "Voice of the Theatre" era and received 200 Hz - 18 kHz. 

 

A modern day compression driver such as a BMS 4590/4592 will offer a broader frequency bandwidth (300 Hz - 22 kHz) in which the old Altec 290/292 compression drivers are incapable of delivering if one wanted to use a 300 Hz Horn designed around 80 years ago today. This is why I class the compression drivers of "The Voice of Theatre" era the weakest link... not the horn. 

 

 

 

Best Regards,

 

Edited by Elliot Thompson - 02 March 2017 at 5:01am

Do you have some real measurements or this sims only? I think it's little beforehand for selling. Bet you never get such a response and directivity with the tractrix horns.

First of all I have seen Teunos sims in his old thread and in this one, and I don't think it's really helpful. For me you're just losing you time, which you can spend on prototyping. Look at this graphs. Have you ever seen something like hf driver with loudness growth from 1kHz to 20kHz? It's bullshit. Did you pay for it? Bad for you.
Second. You have to work with the throat. The directivity pattern mostly depends on throat arrangement than mouth. With this throat you can gain only 30x30 16kHz -10db, not more. It's geometry, not simulations.
Third. Tractrix horns sounds good and can work properly. I have done 2 of a kind and like it. But if we're talking about pa horn it must have stable directivity suitable for some purposes (btw what's your purpose? what kind of speaker are you going to?). Unfortunately the widest directivity i have gained with the tractrix horn was 90x30 and 60x40. That's because of tractrix generatrix. You can find it yourself working with directivity and forms. Just make a horn, then another and so on. Try to make your prototypes cheap and quick because propably it would not work.
Todays audio industry is interested in waveguides for clusters. You can never make a good clusters with such horns. It's out of date. My advice is to concentrate on something modern. All cd horns are done.

PavelP wrote: First of all I have seen Teunos sims in his old thread and in this one, and I don't think it's really helpful. For me you're just losing you time, which you can spend on prototyping. Look at this graphs. Have you ever seen something like hf driver with loudness growth from 1kHz to 20kHz?

Sorry but do you even realize what you are saying here?
You probably just misunderstand what the simulation does. What it does is supply the throat with a constant pressure of 1 pascal and solve the equation for propagation of sound in a linear medium. What it means if the sensitivity increases for increasing frequency or worded differently just the directivity is increasing.
This has absolutely nothing to do with how a driver reacts to the load applied on it or what the input pressure at the throat will be for a given input voltage, which is what a typical measurement does include.
This may sound stupid to you, but it is actually the fundament of horn design.
Impulse response and frequency response can be changed electronically. You cannot change directivity as it is set by the horn.
So what do we want, we want pattern control down low enough so that we can actually splay multiple horns side by side with minimal lobing. However we also want constant directivity for as big a portion of the entire audio bandwidth as we can. For that, we need simulations since small variations can already have big impact on the final results. Simplistic assumptions get you in the right ballpark for sure, but they will not give you the details required if you are this serious about prototyping a relatively expensive product, that is far from simple.
Simple would be trying to achieve these goals, with a 1" driver. There is a reason not a lot of players on the market produce big 2" horns, and its not just because it is a niche market.

If you have any doubts about the validity of the simulations presented here, with the notes as given, you should read up some more.