Go Back   Home > Forums > >

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
Old 22nd June 2021, 12:50 AM   #7181
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Quote:
Originally Posted by mabat View Post
I still can't see what it has to do with size.

I kind of wonder as well. But my own tests of horns about that depth or smaller does show some limitation. So I am curious, because I have not seen satisfying CSD performance. The analysis of the frequency response usually is quite close. But the CSD is just not on par with what I am used to. Although I could probably use dsp processing to get the better performance, but I was hoping to use it just for icing on a cake.

Just recently I got a pair of old Behringer B300 speakers to study this a bit more.
__________________
Hear the real thing!
  Reply With Quote
Old 22nd June 2021, 07:44 AM   #7182
tmuikku is offline tmuikku  Finland
diyAudio Member
 
Join Date: Sep 2004
Location: Savo, Finland
Send a message via ICQ to tmuikku
Isn't "honk" just mouth reflection, or some other discontinuity of the horn wall shape caused reflection? Then it is matter of smooth shape and mouth termination if there is reflections or not isn't it? Reflections happen due to bad profile not due to depth.

Is there a frequency band which has been named "the honk"? In that case the depth is part of the equation, deeper device has mouth reflections happening lower in frequency?
  Reply With Quote
Old 22nd June 2021, 12:21 PM   #7183
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
I don't know what "horn honk" actually is, I only know that there are horns/waveguides that don't produce any subjectively noticeable sound artefacts, which I could call something like that. So to me this is actually not that interesting anymore - we already know how to make transparent-sounding waveguides, I don't need to know more. If someone would figure this out, great, if not, who cares what "horn honk" really was. It's the past anyway.
__________________
https://at-horns.eu
  Reply With Quote
Old 22nd June 2021, 04:11 PM   #7184
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
- I was thinking once again about the input wavefront shape (i.e. the higher duct mode(s) at the exit of a compression driver), its measurement and subsequent usage.

Perhaps the following could be done: I would create a freely available waveguide model - something smallish that everyone could download and (let it) print on a 3D printer. Then from a prescribed set of SPL measurements on this waveguide a specialized program would calculate the coefficients of the modes, i.e. the "shape" of the wavefront for a particular driver used (it would have the knowledge of the simulation results of what each mode does on that particular waveguide). This way, if there was enough interest, quite a large database of various drivers could be collected.

The question is, however: would this be of any use in the end? Are we able to design a waveguide utilizing the knowledge of an actual input wavefront to make even better results? I can't imagine how would I do that. Some crazy optimization?
__________________
https://at-horns.eu

Last edited by mabat; 22nd June 2021 at 04:15 PM.
  Reply With Quote
Old 22nd June 2021, 05:05 PM   #7185
jcarothers is offline jcarothers
diyAudio Member
 
Join Date: Jun 2016
I'm wary of collecting a "database" of measurements (from which comparisons would be made) from multiple sources. Too many variables at play there, and it's too easy for differences in experience, equipment, etc to influence the data.

Quote:
Originally Posted by mabat View Post
The question is, however: would this be of any use in the end? Are we able to design a waveguide utilizing the knowledge of an actual input wavefront to make even better results? I can't imagine how would I do that. Some crazy optimization?
I think this is the most important question here. I can imagine one way in which this could be incorporated into an Ath simulation/optimization routine:
  1. Determine the prevalence of the first few wavefront modes for a given compression driver. Normalize them to generate scaling factors.
  2. Simulate the output of each mode in the waveguide using Ath, as you have shown.
  3. Perform a weighted sum of all (significant) modes to generate a more realistic simulation. Optimize this output.

Step 1 seems the hardest part right now, but perhaps a plane wave tube could solve that?

EDIT: re-reading your post, it seems we might be describing the same process. Hah. My first point still stands, however.

Last edited by jcarothers; 22nd June 2021 at 05:08 PM.
  Reply With Quote
Old 22nd June 2021, 05:41 PM   #7186
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
Simply stated, if we suppose the wavefront can be sufficiently measured using the method I described above (and it seems doable to me), how to utilize this knowledge further?
__________________
https://at-horns.eu

Last edited by mabat; 22nd June 2021 at 05:56 PM.
  Reply With Quote
Old 22nd June 2021, 05:57 PM   #7187
jcarothers is offline jcarothers
diyAudio Member
 
Join Date: Jun 2016
It seems to me that if you could determine the relative influence of each mode of the wavefront from a specific CD (by the process above), you could simulate each mode in Abec and generate a weighted sum of those simulations that very accurately predicts the performance of that CD. At that point you could optimize the waveguide based on that weighted sum model instead of the 0,0 mode alone.

Or in fewer words: you can generate a more accurate model of the CD (as a weighted sum of the first few modes) and use that model to optimize the waveguide.

It's a process that would have to be repeated with each CD of interest, but it could allow for more accurate predictions of waveguide performance.
  Reply With Quote
Old 22nd June 2021, 06:02 PM   #7188
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
Quote:
Originally Posted by jcarothers View Post
... At that point you could optimize the waveguide based on that weighted sum model instead of the 0,0 mode alone.
But how would you optimize it? At least that seems the hardest part to me.

- To have more accurate model is of no use if one doesn't know how to improve the results. That's what I meant. Do we know how to improve the results?
__________________
https://at-horns.eu

Last edited by mabat; 22nd June 2021 at 06:06 PM.
  Reply With Quote
Old 22nd June 2021, 06:13 PM   #7189
jcarothers is offline jcarothers
diyAudio Member
 
Join Date: Jun 2016
Are you asking about the process of optimizing the design to achieve a certain goal, or about what the goal should be in the first place?
  Reply With Quote
Old 22nd June 2021, 06:17 PM   #7190
mabat is offline mabat  Czech Republic
diyAudio Member
 
mabat's Avatar
 
Join Date: Sep 2004
Location: Prague, Czechia
How would you proceed if you had a wavefront model of a particular driver? How would your optimization look like? What exactly would you do?
__________________
https://at-horns.eu
  Reply With Quote

Reply


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
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 12:12 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