Tractrix timber horn

I'm considering a timber tractrix horn with a GPA 399. It will have an Fc of 250Hz & the mouth dimensions will be 23" wide X 9" high x 16.87" deep with a 1" motorboard. It will be similar to the attached pic.

There's plenty of info to determine the lowest frequency that the proposed size horn will go to, the program used to generate the dimensions will calculate this & many other things. My problem is determining how high this horn will go to.

Would anyone know if it will go up to the upper limit of the driver? That is, to 15K?
Thanks,
John

Unless there is an obstruction, the upper limit of the driver should be the answer.

i like the bass traps.. that being said, what are you using for the bottom 4 octaves? flat from 20 - 20,000 hz is a hard task for just a two way or even a three way system.

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Originally Posted by valhallax

i like the bass traps.. that being said, what are you using for the bottom 4 octaves? flat from 20 - 20,000 hz is a hard task for just a two way or even a three way system.

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To clarify, the picture is not of my system, but something I found on the net. I just used this as an example of what the horn will look like.
The system will comprise of: REL sub woofer......either Klipsch Belle bass cab or Onken with 416.....JBL 2404H.
I figure I'll need the 2404 as the 399's only go to 15K.

My original question was really to determine if the mid would go all the way to 15K or cut off at 6-7K. If it will extend all the way to 15K it will make the crossover for the 2404 a lot simpler.

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My original question was really to determine if the mid would go all the way to 15K or cut off at 6-7K. If it will extend all the way to 15K it will make the crossover for the 2404 a lot simpler.

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Your original question is ambiguous enough that I'm unsure if you know the following ( your most recent post suggests otherwise ) , so ;

> A horn similar in size to the displayed pic will give a rolled-off HF starting at say 3 or 5Kz ( though it'll still go up to 15K which is the HF limit of the 399 /just rolled-off at around 6db per octave) .

> The size, Q & type of horn will dictate relative response levels of the HF to MF .

> The "real"top-end performance ( extension ) will barely change ( barring obstructions ) when you play around with the various horn parameters. What does change is the relative level of mid to HF ( bigger horn reinforces lower & lower in frequency ) .
> "Real" HF performance is measured at a constant distance to the diaphragm ( not to the lip of horn ) .

> One way or another , you'll need to measure what you construct before you can confidently add in a tweeter ( with appropriate nerwork ) and achieve a flat response from 500hz to 20Khz.

:)

There a bad pun to be had here somewhere...the timbre of the timber horn....never mind.:p

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Originally Posted by Earl K

Your original question is ambiguous enough that I'm unsure if you know the following ( your most recent post suggests otherwise ) , so ;

> A horn similar in size to the displayed pic will give a rolled-off HF starting at say 3 or 5Kz ( though it'll still go up to 15K which is the HF limit of the 399 /just rolled-off at around 6db per octave) .

> The size, Q & type of horn will dictate relative response levels of the HF to MF .

> The "real"top-end performance ( extension ) will barely change ( barring obstructions ) when you play around with the various horn parameters. What does change is the relative level of mid to HF ( bigger horn reinforces lower & lower in frequency ) .
> "Real" HF performance is measured at a constant distance to the diaphragm ( not to the lip of horn ) .

> One way or another , you'll need to measure what you construct before you can confidently add in a tweeter ( with appropriate nerwork ) and achieve a flat response from 500hz to 20Khz.

:)

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Sorry if my question was ambiguous, but as you can see, this is a bit above my technical knowledge.

I see what you are saying though, in that the driver will still perform out to it's limit, but will be rolled off at 6db/octave. That type of technical info is what I was looking for, so thanks.