Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th June 2019, 04:40 AM   #31
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
Wow! Thank you Patrick for probing the piece. It seems you are really the right person to do it
I'm sure there are still flaws. I'm making notes and will try to look at that for the next release. Thanks again.
  Reply With Quote
Old 7th June 2019, 06:29 AM   #32
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
Quote:
Originally Posted by Patrick Bateman View Post
In "solving" for the OS waveguide, I noticed that there's one domain, but in the ath15 waveguide, there are zero.

I think the problem is in the mesh that's generated. Here's the header for the OS waveguide mesh generated by ath4.exe:

$MeshFormat
2.2 0 8
$EndMeshFormat
$PhysicalNames
3
2 10 "drive"
2 20 "wg"
2 30 "ifc"
$EndPhysicalNames
$Nodes
849

And here's the header for the ath15 mesh. Note the missing fields.

$MeshFormat
2.2 0 8
$EndMeshFormat
$Nodes
1568
Only the mesh file intended for ABEC has these physical goups, i.e. names (tags) for the several horn sections - the throat surfrace "drive", horn walls "wg" and the interface "ifc". And also it is only a quarter of the whole horn.

The mesh file in the root project folder is basically just a different form of the STL. You are not supposed to be using this mesh for a simulation. I should give these files a different names I guess.
  Reply With Quote
Old 7th June 2019, 06:34 AM   #33
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
Quote:
Originally Posted by Patrick Bateman View Post
One caveat : I've noticed that ABEC isn't able to make it's pretty 3D pictures. I think that's because there's something missing from "observation.txt"

Having said that, you CAN see the polars in VACs, which is really what we're after, right?
What do you mean by these 3D pictures? If you mean the Fields feature (pressure distrubution accross some plane surface coded in colors), it's no problem to include that. I made these is the past, they are pretty but actually never found a real merit for them. I will make it an option in the next release. It can show you the nearfield (or the interior of the horn) nicely. But what do you really take from that?

Last edited by mabat; 7th June 2019 at 06:36 AM.
  Reply With Quote
Old 7th June 2019, 06:46 AM   #34
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
BTW, this is how Fredrik's mesh for ABEC looks like. I guess it would take years to calculate
Unfortunately I don't know the cause. That looks like a question for the Gmsh authors. I will try.

I will talk more about the ABEC part later. There's much to explain I guess.
Attached Images
File Type: png Fmesh-abec.png (116.8 KB, 443 views)

Last edited by mabat; 7th June 2019 at 06:53 AM.
  Reply With Quote
Old 7th June 2019, 10:04 AM   #35
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
I could make an option of a dome tweeter instead of a plane wave (which is what it is now) for the throat. At least I believe it would be possible. Only it is not so obvious how to do it. Should I include the surround? How to define the shape? Or does that make any sense at all?

BTW, the wavefront could also by modeled as non-flat. I only don't know if there is anyone who could utilize such feature.

Last edited by mabat; 7th June 2019 at 10:13 AM.
  Reply With Quote
Old 7th June 2019, 10:58 AM   #36
FredrikC is offline FredrikC  Norway
diyAudio Member
 
Join Date: Aug 2010
Tried it on my laptop now and the mesh is normal resolution there.
  Reply With Quote
Old 7th June 2019, 11:00 AM   #37
cowanaudio is offline cowanaudio  Australia
diyAudio Member
 
cowanaudio's Avatar
 
Join Date: Jul 2004
Location: Canberra
I'd love to play along but when I run ath4.exe it flashes up for about a tenth of a second then disappears. I have gmsh-4.3.dll in the same directory as ath4.exe.

System is an i7 running win10

I have downloaded the sw and gmsh twice with the same result.
__________________
Don't Procrastinate....Just Do It!
  Reply With Quote
Old 7th June 2019, 11:11 AM   #38
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
This is the icon you are looking for. You must run a command line window first. Search for cmd.exe (usually under C:\Windows\...), make a shortcut icon of it somewhere and in the properties set the directory of your ath4.exe ("Start in"). Then just double-click on the shortcut to get to the tool. Then you can run it as shown in the manual.

Fredrik, maybe your computer just wants to show you what it can do. I wouldn't feel safe...
Attached Images
File Type: png cmd.png (666 Bytes, 497 views)

Last edited by mabat; 7th June 2019 at 11:25 AM.
  Reply With Quote
Old 7th June 2019, 11:33 AM   #39
cowanaudio is offline cowanaudio  Australia
diyAudio Member
 
cowanaudio's Avatar
 
Join Date: Jul 2004
Location: Canberra
Thankyou. I'm getting closer, I'm now coming up with an error "Unknown output file format" when I try to open oswg.cfg. This error appears just after the width and height of the wg is displayed.

It has created the directory D:\Horns\ABEC_project with four files in it.
__________________
Don't Procrastinate....Just Do It!

Last edited by cowanaudio; 7th June 2019 at 11:42 AM.
  Reply With Quote
Old 7th June 2019, 11:44 AM   #40
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague
This is getting weird. It seems like Gmsh library does different things on different machines. This error comes from the Gmsh SDK when it doesn't recognize the file format requested to export the data. It does that by looking at the file extension (which is hardcoded in the source code!). The only explanation I can imagine is that you have a different Gmsh library, which can't do STL or MSH. But that seems also as a nonsense. I don't know

I will add some more detailed debug info. It may still be a bug on my side.

- You can try to comment or delete the line "Out.DestDir = ..." but I doubt that will help.

Last edited by mabat; 7th June 2019 at 11:58 AM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Easy horn (Eazy Horn) still work? Alternatives? Soldermizer Subwoofers 2 4th March 2014 05:01 PM
For sale: Sound easy V18 & Acoustic-dimension stepped attenuator Tazzz Swap Meet 8 3rd November 2012 08:00 AM
easy exponential horn speakers anyone? 12345chris Full Range 9 21st March 2012 11:32 AM
Easy horn, quadrant horn? Hentai Multi-Way 2 29th January 2012 08:50 AM
An easy to build classic horn? dabbler Multi-Way 22 1st September 2011 08:01 AM


New To Site? Need Help?

All times are GMT. The time now is 08:53 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki