Acoustic Horn Design – The Easy Way (Ath4)

I was playing a bit with Axidriver and decomposed EXAR400 without conical extension because when added I'm getting mess.

1703971049768.png
1703971146178.png


1703971260092.png
 
  • Like
Reactions: camplo
thank you @fluid, i finally got it running. SB26CDC dome in a waveguide with enclosure. Looks bad but you got to start somewhere...
Finally i can get into optimization. I really hope calculation time is quicker on my CAD workstation. This result took me 2h on a pretty quick laptop, but it seems to be RAM limited.

I'm a broken record on this one, but you can get fourteen core Xeons for $20 on eBay and the RAM is nearly free. I'm personally using Dell T5810s, I have four of them.

I have a $2500 Macbook and a $2500 Intel laptop with a 2023 CPU in it, and my seven year old Dell T5810s blow them out of the water for this stuff. Quad pumped DDR4 ram and fourteen xeon cores might be very old, but they still obliterate laptops because Intel CPUs haven't progressed a whole lot in the last ten years, and laptops are inherently unstable because they lack DDR RAM and massive heatsinks. (Even a twelve core laptop will get throttled because the heatsink isn't sufficiently large; Macbooks are fast but running native is always faster than emulation.)
 
  • Like
Reactions: VoxCelestial
i can second that. My CAD worksation is a 7 year old HP machine with one of those 12core XEONs and lots of ECC memory. I paid 400 € for that thing and another 200€ for a 1080TI and its so much better than pretty much any laptop i can buy for all things work relatet.
 
I stand corrected (maybe). Using your @CinnamonRolls Source Contour it looks very wild. I used the one posted by augerpro sometime ago before and it was a lot cleaner...
What is the current consensus for a compression driver to 1,2 kHz looking for clean response and use with a passive crossover bestcase scenario? 😛 Long term goal is to go MEH but would love to built a 2-way first.
Have a good new year everyone!
 

Attachments

  • Polars1.jpg
    Polars1.jpg
    128 KB · Views: 84
  • Polarlines1.jpg
    Polarlines1.jpg
    138.1 KB · Views: 81
Last edited:
  • Like
Reactions: CinnamonRolls
Wow. My measurements are way off. My dome is a full millimeter taller + 3 mm narrower and my surrounds were 0.5 mm taller + a full mm wider. Also, I didn't know how to deal with the foil piece/glue because it's at 26mm O.D. and is raised up to the top of the surround with the dome inside the cylinder. For simulation, it looks like it's better to ignore the foil piece and widen the dome. Glad @zangg tested it against a better model otherwise I wouldn't have learned.

Thanks for the model, @fluid
 
New Ath4.9.0 user here. I have recently installed the software and adapted the .cfg file as instructed. I found a helpful sample script in this forum and ran it through the Ath4 at the cmd line and generated files in the Horn directory (original .cfg file attached as .txt file).

I am able to view the .stl file through meshmixer and generated an ABEC project. However, I am unable to get the ABEC project to work with AKABAK. Joerg Panzer granted me a license for noncommercial use of AKABAK and instructed me to use the Import ABEC Project under the Tools menu in AKABAK. I have read in the forum the ABEC is preferred to AKABAK and I guess I'm not sure if I really need to try to get a license for ABEC or if this is a user error situation. Before I proceed further I was hoping to get input from more experienced users. I can attach other files if needed / helpful, but I wanted to keep this short.

Thanks,

Jon
 

Attachments

Joerg won't give you a student licence for ABEC anymore, it does not matter though you can do everything in the demo version of ABEC and if you have a full version of VACS you can save the spectrum output there. Ath can also use the report format or produce FRD files.

Don't waste your time trying to make AKABAK import the ABEC projects.
 
Thanks fluid. That was my suspicion.

I have a full version of VACs and AKABAK (with student licenses) but only the professional version of ABEC (which requires a license). I can't seem to find a functioning download for the demo / trial version of ABEC. I emailed Joerg to see if he could give access to a trial version but I haven't heard back. Might have to see if someone has a file to share.

My friend here in Seattle (with four 3d printers and 2 CNC's) and I are eager for me to figure this out so we can start building stuff 😛.
 
I've only used compression drivers in waveguides so I'm curious to understand domes. In my very limited experience, compression drivers sound extremely good in freestanding R-OSSEs. I can't say they sound the best (or even better) because I have exactly zero idea what a really good dome implementation sounds like.
 
In my simulations going from domes to compression drivers, i can see how you end up using compression drivers. When you are looking into good DI and reducing baffle step influence, it just looks very good in simulation.
For the most part, I just took Marcel's "Tritonia" waveguide and made some tweaks to it, so that it:

1) worked better with my dome tweeter

2) was more asymmetrical
as it was my general starting point aswell, i have been playing with all variables but somehow can not reliably hit dimensions i am aiming for. Morph to targetwidth and targetheight seem to be ignored bei ath somehow...