Go Back   Home > Forums > >

Multi-Way Conventional loudspeakers with crossovers

1.4" or 2" throat large constant directivity horns you can actually buy!
1.4" or 2" throat large constant directivity horns you can actually buy!
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
Old 3rd June 2019, 11:24 PM   #421
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Is the waveguide unbaffled? That will make the edge treatment critical and not actually give the best results. A baffle makes things much better.

Reminds me of doing FEA in the old days. I never liked all that tedious meshing - we didn't have auto meshing then.
__________________
Earl Geddes Gedlee Website
  Reply With Quote
Old 3rd June 2019, 11:28 PM   #422
FredrikC is offline FredrikC  Norway
diyAudio Member
 
Join Date: Aug 2010
It's in an infinite baffle, it just looks transparent in ABEC.
  Reply With Quote
Old 4th June 2019, 04:41 AM   #423
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
Quote:
Originally Posted by FredrikC View Post
... Had a quick look at the round OSWG and it works like a charm.
Try the second one then

Quote:
Originally Posted by gedlee View Post
Is the waveguide unbaffled? That will make the edge treatment critical and not actually give the best results. A baffle makes things much better.
As Fredrik says it's in an infinite baffle. Otherwise it would be a disaster as you say. It would be possible to run it that way however (been there), it would take much more computation time as the back side would also need to be modeled - it can't do sheets of zero thickness. I will definitely add an option of a box as an alternative to IB condition. Yeah, Gmsh makes the modeling a piece of cake.
Attached Images
File Type: png ath15.png (239.4 KB, 504 views)
__________________
https://at-horns.eu
  Reply With Quote
Old 4th June 2019, 12:38 PM   #424
FredrikC is offline FredrikC  Norway
diyAudio Member
 
Join Date: Aug 2010
Quote:
Originally Posted by mabat View Post
Try the second one then
Works perfectly, and the response looks really good! Better than the round OSWG which still show some irregularity in the 0-20 degree area.

Round mabat- OSWG curves:
mabat round oswg.png

Rectangular mabat design (ATH-15)
mabat ath15.png

My 10" device which is not a OSWG, but more of a OSWG throat merged to a lage radius from throat to mouth:
off axis FR curves.PNG



One ABEC specific question; I see that you are using a curved/spherical interface at the horn mouth.
sphericalinterface.PNG

Why is that? I have so far only used a flat mesh for the interface:

Last edited by FredrikC; 4th June 2019 at 01:02 PM.
  Reply With Quote
Old 4th June 2019, 01:44 PM   #425
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
Your solution looks also very smooth Fredrik. When I try to squeeze my horn to 10" (256 x 236 mm actually) I get to these results (polars are 0 - 75; step 7.5) -

More on the interface later...
Attached Images
File Type: png ath10-pmap-horiz.PNG (77.2 KB, 438 views)
File Type: png ath10-pmap-diagonal.PNG (85.5 KB, 438 views)
File Type: png ath10-polars-0-75.PNG (45.2 KB, 423 views)
File Type: jpg ath10.jpg (39.4 KB, 426 views)
Attached Files
File Type: zip ath10.zip (77.1 KB, 3 views)
__________________
https://at-horns.eu
  Reply With Quote
Old 4th June 2019, 03:29 PM   #426
FredrikC is offline FredrikC  Norway
diyAudio Member
 
Join Date: Aug 2010
Nice! Your design seems to have better control over directivity at the lower end of the passband.

Will your tool allow for altering the throat diameter and throat entry angle?

Last edited by FredrikC; 4th June 2019 at 03:33 PM.
  Reply With Quote
Old 4th June 2019, 03:45 PM   #427
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
For sure, otherwise it would be useless. This is an excerpt from the definition script (the horn just shown), all can be changed:

Code:
  ThroatDiameter = 25.4                 ; [mm]
  ThroatAngle = 0                       ; [deg]
  Coverage_Horizontal = 95             ; [deg]
  Coverage_Vertical = 90                ; [deg]
  Depth = 90                           ; [mm]
  Depth.ConicSectionPart = 0.5          ; 0.5
  Shape = raw2rect                      ; raw | raw2rect
  Shape.FixedPart = 0.2                 ; 0.2
  Shape.CornerRadius = 38.0             ; [mm]
  SEExp = 2.3                           ; superellipse exponent
  
  Termination = baffle                  ; baffle | free-air
  ;Termination.Angle = 90.0              ; (for baffle; default = 90 deg)
It seems to me that in case of a rectangular shape the available mouth area (for a fixed enclosure width) can actually be utilized better. Just my impression.
__________________
https://at-horns.eu
  Reply With Quote
Old 4th June 2019, 08:23 PM   #428
Flaesh is offline Flaesh  Russian Federation
diyAudio Member
 
Flaesh's Avatar
 
Join Date: Dec 2009
Location: Eburg
Quote:
Originally Posted by jzagaja View Post
Large termination like in K402. Do you remember Gorge Soong work?
Link Geddes on Waveguides
  Reply With Quote
Old 4th June 2019, 08:37 PM   #429
Flaesh is offline Flaesh  Russian Federation
diyAudio Member
 
Flaesh's Avatar
 
Join Date: Dec 2009
Location: Eburg
Quote:
Originally Posted by mabat View Post
here are the basic STLs that would fit into Jacek's machine, you can look.

(online STL viewer: Free online STL viewer)
Marcel,
what is xover frequency for this WG? And what driver?
  Reply With Quote
Old 5th June 2019, 04:30 AM   #430
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
I don't know the particular driver. I got throat size, entry angle and the size limit so I came with this OSWG which is about 15.3" (6.3" depth) and "ATH" which is 17.3" x 15" (7"). Since the throat is for 1.4" I would expect the xover around 700 Hz without issues. Maybe a bit lower with the ATH. Depends on the driver and the woofer used. The request was also for 80x80 coverage which may complicate things a bit. Personally I would make it wider.
__________________
https://at-horns.eu

Last edited by mabat; 5th June 2019 at 04:33 AM.
  Reply With Quote

Reply


1.4" or 2" throat large constant directivity horns you can actually buy!Hide this!Advertise here!
Thread Tools

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
Custom dual throat horns for two inch throat drivers Mike Caldwell Swap Meet 2 12th February 2017 04:28 AM
which fullrange might work as well as LE5A on a 250Hz tractrix w. 2.5" x 2.5" throat? freddi Full Range 19 4th December 2015 07:25 PM
3 large EV fiberglass horns for 12" woofer cjh Swap Meet 0 28th October 2014 07:00 AM
EH 500 Radial Horns, 2" Throat, 500 Hz macka Swap Meet 0 13th June 2014 08:37 AM


New To Site? Need Help?

All times are GMT. The time now is 10:54 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki