I'm pretty sure it must have been meant as half-angle value.
You have 7.2 degrees version already uploaded: http://www.at-horns.eu/athex.html#460-25 🙂
You have 7.2 degrees version already uploaded: http://www.at-horns.eu/athex.html#460-25 🙂
Yes, that was half angle ("dR/dL = tan(A)"):
https://www.diyaudio.com/community/threads/does-anyone-know-the-tad-exit-angle.213881/post-3052737
So you have it pretty accurate 🙂
https://www.diyaudio.com/community/threads/does-anyone-know-the-tad-exit-angle.213881/post-3052737
So you have it pretty accurate 🙂
Here are some measurements of ATHEX 520-25 with BMS 4544. Thanks mabat for your work. 🙂
For the TD-2001 I'm going to release ATHEX-E-280-25 soon -
(To be competitive as a "600 Hz cut-off" horn 🙂 )
(To be competitive as a "600 Hz cut-off" horn 🙂 )
That's marvelous. Good job, I really like the looks, it's terrific (and the performance of course!). It's always great to see this.
(It just may be unnecessarily a little too big for a regular 1" driver - You probably won't use it much below 800-900 Hz anyway...)
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@CristopherPwandek - was it necessary to split the petal segments in half? They should print fine in one piece... But perhaps you had a reason for that (?).
No, it was not really necessary. I thought that it would look nice, when the printing lines are not angled across one petal. But with my amateurish gluing technique, I'll have to sand and fill anyway. ^^ (I`m really new in the 3D printing game and the ATHEX was my second print after the 3DBenchy)
Ah, I didn't think about that... Probably becase I wouldn't even consider keeping it as it comes from the printer. For your second print it's perfect, hats off.
- But I like the "Star Wars" look 🙂 It's probably the infill that shows through the surface, it actually makes a great finish.
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I quickly tried to overlay the measured data by Cristopher and the BEM prediction (the black lines). There's really no surprise here.
At 1 m the exact rotation axis can still have an appreciable effect, so it still may be off a bit just for that reason.
What was measured are in fact "vertical" polars as I labeled them (ignore the noise above 10 kHz off axis) -
At 1 m the exact rotation axis can still have an appreciable effect, so it still may be off a bit just for that reason.
What was measured are in fact "vertical" polars as I labeled them (ignore the noise above 10 kHz off axis) -
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- It seems that the center of rotation was ~18 cm from the throat 🙂
Regarding the ripples between 500-3k, I guess this has not much to do with the waveguide. Could be a reflection off a nearby object.
Regarding the ripples between 500-3k, I guess this has not much to do with the waveguide. Could be a reflection off a nearby object.
Marcel, that is an amazing accuracy for a model in acoustics. Congratulations!
Greetings all,
I have a wave-guide x and y coordinates of which are described by (different) 3rd order polynomials. Since I know the length of the wave-guide, i.e., the z_length coordinate, can ATH be used to calculate the mouth x and y coordinates between z_length and z_max,, wherein z_max > z_length?
Kindest regards,
M
I have a wave-guide x and y coordinates of which are described by (different) 3rd order polynomials. Since I know the length of the wave-guide, i.e., the z_length coordinate, can ATH be used to calculate the mouth x and y coordinates between z_length and z_max,, wherein z_max > z_length?
Kindest regards,
M
This is the trouble of describing a 3D waveguide geometry in a consistent manner, it can get mixed up easily. I figured out that you would like to extend some profile formula beyond some interval of its parameter with another ("ATH") formula (correct me if I'm wrong). I don't know, I think a more specific example would be necessary.
Back to @CristopherPwandek's measurements, the absolute SPL fall off at HFs is quite significant here. I wonder how much does the BMS 4544 itself contribute (the slope is like -8dB/octave) and what would some other drivers show. Do you have any other drivers you could try with the waveguide?
Perhaps the constant directivity of this horn is still too much constant... 🙂 (I didn't think so when designing them.)
Perhaps the constant directivity of this horn is still too much constant... 🙂 (I didn't think so when designing them.)
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BTW, this may be useful for others as well - the description of the file format that I use for the Fusion 360 imports. It was specifically designed with horn geometry in mind and it's pretty flexible - The ASC File Format (all ATHEX horns are created this way).
The unit is [cm] by default.
The unit is [cm] by default.