Acoustic Horn Design - The Practical Way

[Antoine8082]

Antoine, i'd love to see the predicted polars if you can post them!

Hi Drof,

Attached is the polars :
A : at the "angle" plane
H : horizontal
V : vertical
(I haven't found how to symmetrize the graph... Please tell me !)

And the config file.
Remember, the first constraint is the compact overall dimensions, that impose concessions !

It's my first work on horns, if any advice, do not hesitate !

 

[Antoine8082]

First piece of the enclosure!
The printer bed is 310mm and the printed part is 300mm!
Second under construction...

 

[Antoine8082]

To get a symmetrical contour view in VACS, did you simply set the first value at -90 ?
MapAngleRange = -90,90,39

I'm at work so I can't test, but I feel that it will double the calculation time...
I just need a symmetric.

I have another question for grid coordinat export.
Please someone show me how to set/know :
ProfileRange : How to know "from" and "to" ?
And SliceRange : Same question

GridExport:<tag> = {
ProfileRange = <from>,<to>
SliceRange = <from>,<to>
ExportProfiles = 0|1
ExportSlices = 0|1
Scale = 1.0
Delimiter = ";"
FileExtension = "csv"
SeparateFiles = 0|1
}

As I work with Solidworks since years, I'll try to import it to get smooth surfaces and avoid mesh.
Thanks.

 

[kipman725]

Hi Antonie your boombox is very impressive. With a 480Wh battery It should run for days (unless something has high idle current). I use a 1200wh battery with a 6 way system of TPA3251 and get about 48hrs runtime. Please let me know how you get on with the IcePower A1000 as single supply powerful amplifiers are rare.

 

[Antoine8082]

Hi Antonie your boombox is very impressive. With a 480Wh battery It should run for days (unless something has high idle current). I use a 1200wh battery with a 6 way system of TPA3251 and get about 48hrs runtime. Please let me know how you get on with the IcePower A1000 as single supply powerful amplifiers are rare.

Hi Kipman,
As usual, it depend on the playing level...
I also have a JAB3+ for the compression driver.
Sure, I'll make a report for you.
Second part is done, the third is printing.

 

[Antoine8082]

One more!
The latest is printing.

 

[Antoine8082]

Enclosure done!

 

[TNT]

Looks very good. What printer are you using?

//

 

[Antoine8082]

Looks very good. What printer are you using?

//

Hi,

It's a tuned Sunlu S8 frame.
Custom print head, direct drive, bed sensor.
SKR V1.4 turbo, Raspberry Pi, Klipper firmware...

It's my first try with PETG Carbon, it's "nice", but not as usual...
I also own a 3040CNC, 800w, WC, to work on wood/alu.

 

[kipman725]

Excelent, what goes in the top hole?

 

[Antoine8082]

Excelent, what goes in the top hole?

The top square hole is for a plate that will receive :
-On/off switch from the anti-spark switch.
-The DSP 6 pins connector.
-The battery voltage display.
-The 4 potentiometers, Vol, bass, med, high.
-Charger connector.

 

[Antoine8082]

Hello,

Long time.
I was waiting to receive an aluminium plate to increase my aluminium heatsink thickness.
I was feel it too thin to get a nice heat transfert.

Now I can start to assemble it !

 

[TNT]

Some practicalities...

https://www.diyaudio.com/community/threads/hornflower-2-way-point-source.386363/

//

 

[Antoine8082]

Hello,
Hardware done!
All work as it should.
I can start measurements and DSP tuning.
(Yes, it's a foldable battery!)

 

[stv]

hello @Antoine8082,
great project and documentation!
how did you tune the woofers? their Qts seems to be quite low...

 

[Quza]

I just installed ath, gmsh, gnuplot, abec, etc and ran the demo1.cfg file which throws gmsh errors until it aborts.
My ath.cfg: https://pastebin.com/BSZegwjF
demo1.cfg: https://pastebin.com/cDqz44qR
The command line: https://pastebin.com/kMC9MbZL

I'm pretty sure I followed the installation instructions correctly. Any idea what's wrong?

 

[Patrick Bateman]

I used to get that error.

It's been a while, but IIRC, I was able to fix it by updating to the latest version of gmsh

Or I may have it completely backwards, and it may have required down-revving:

Check out these two posts:

https://www.google.com/search?q=site:diyaudio.com+"unknown+control+point"

 

[Quza]

Thanks, downgrading ath worked for me.
ath 4.8.2 throws this error with gmsh 4.10.5
ath 4.7.0 works fine with gmsh 4.10.5

 

[Quza]

https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-6991933
Here's the actual fix to "unknown control point". Use the beta 😀

 

[CristopherPwandek]

Hi guys, here are some pictures of mabats ATHEX 520 horn with 3 integrated midrange drivers.

My first prototype measurements of ATHEX 520 horn with BMS 4544 1" were very promising:

ATHEX 520 measurements

The ATHEX 520 horn has down to about 500Hz still a good directional radiation, which I can not use with the BMS 4544, because at least at about 1200Hz the high pass must be set. Therefore, I had the plan to integrate midrange drivers in the horn. I have used - mainly for cost reasons - 3 pieces of LaVoce FSF030.70 16 Ohm. In first simulations they seemed not so ideal for smaller volumes. But the measurements were not as bad as suspected. Due to the reflections of the midrange drivers on the diaphragm of the compression driver, I have a cancelation at about 1900Hz. Here I applied the frequency separation at about 1500Hz. Transition to the woofer I have just at about 400Hz. My measurements are made in the room and not really reliable below 400Hz - here I would have to make better measurements outside.

Right now I'm only listening mono, but I finished printing the parts for the second horn today and I'm really excited about the first stereo listening. I love to hear close (like 1,5m) to avoid the most reflections and enjoy a clear center image and singers "screaming" right in front my face. ^^

Thanks for the active community here that inspired me to do this project.
Christopher