Acoustic Horn Design – The Easy Way (Ath4)

[mabat]

Finally I have it working (there's always something more important to do...). I have about 8.5 ms of reflection-free time (1.5m tube).

I'm still only experimenting with the setup to see how it works - this is B&C DE360, BTW (absolute SPL levels not calibrated).

 

[ErnieM]

ES-2000 Biradial with Various Compression Drivers – Joseph Crowe

DE360 on a horn.

 

[mabat]

The raw responses (so far without any calibration or correction) of the six microphones in the tube.
I'm only afraid that the disturbances caused by the mic mountings will be too high. How to check that?

 

[mabat]

BTW there's definitely something ringing within the driver around 8 kHz, I think this is present in almost all of the published measurements of this driver.

 

[gedlee]

The raw responses (so far without any calibration or correction) of the six microphones in the tube.
I'm only afraid that the disturbances caused by the mic mountings will be too high. How to check that?

That would be hard to check with acoustics.

I'm thinking that the levels < 2 kHz should track each other. I see no reason that they should be different. Maybe you can just adjust the levels for 1 kHz -> 2 kHz to match.

 

[mabat]

I'm thinking that the levels < 2 kHz should track each other. I see no reason that they should be different. Maybe you can just adjust the levels for 1 kHz -> 2 kHz to match.

Sure, that's still to be done - I'll create a correction curve for each microphone to give the same FR at the position of the first one.

 

[mabat]

- All 6 mics (WM-61A) at the same position (I'm quite surprised, I expected bigger differences):

 

[mabat]

Back to horns - preliminary results of one of my recent designs: Free standing waveguide for 1" driver, ⌀260 mm. Thanks to Pet007 who printed and measured the prototype.

 

[onni]

Great results and nice looking print!

Why the black tape?

 

[mabat]

The print was two-part (and maybe there were still some issues, I don't know).

Frankly I'm astonished by the DI curve - I wouldn't expect such good results for a free standing horn of this size but maybe it's an advantage after all.

 

[mabat]

These were the simulations -

 

[mabat]

With B&C DE360 -

 

[TNT]

Nice! Could you please repost the impedance plots for this particular horn?

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[pet007]

Great results and nice looking print!
Why the black tape?

Just for highlighting that perfect horn profile
.....tapes were here only as support during gluing both parts together...

 

[TNT]

... and how did they sound

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[mabat]

B&C DE502

 

[mabat]

Nice! Could you please repost the impedance plots for this particular horn?

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I have only an impedance for a flat source wavefront and smaller throat angle. For the final shape the throat angle was increased to better match a typical driver. So this is not as easy.
It's quite easy to trade between loading and beaming however - you can choose or mix the two in whatever way you prefer. This is what I chose.

 

[mabat]

Today is especially fruitful

(260 x 200 mm)

 

[kessito]

W.o.w.

 

[TNT]

Very stylish!!

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