Segmented Wire Stator ESL simulator (esl_seg_ui) - Page 7 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

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 6th June 2013, 08:39 PM   #61
diyAudio Member
 
Join Date: Dec 2012
Quote:
Originally Posted by bolserst View Post
Hello jeronimo83,

Based on your ESL_SEG_UI inputs, the attached schematics show resistor values and wiring connections that would give the calculated response.
If I understand your electrical circuit description correctly, you should use the resistor values in Configuration (4).


Configuration (1) is most directly comparable with the inputs from the program.
Configuration (2) is the symmetric version of (1) where half of the resistance is placed on each stator segment.

Configuration (3) left and right side portion of each segement are connected and driven with one resistor ladder.
Configuration (4) is the symmetric version of (3)


As mentioned previously in this thread, often the resistor for segment 1 is moved to the primary side of the transformer where it can provide core saturation protection as well. In your case with a 150:1 step-up ratio, the 25K resistor could be replaced with a 1 ohm resistor on the primary side of the transformer(resistor "R" in the schematics).
Bolserst, thanks very much for your illustrations. Apparently I made a big mistake. Fortunately, I can make some changes to the circuits that I've soldered quite easily to match configuration nr 1. I will pass the 25k resistor and replace it with a 1 ohm resistor in series with the primary winding of the transformer.

Thanks, again.

Jeroen

(PS sorry for interrupting this thread.)
  Reply With Quote
Old 6th June 2013, 09:00 PM   #62
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
that why the thread is here Jeronimo , by the way ur from 83 ? where do you live in the Netherlands ? because i live in Den Haag Always nice to know some people that share the same hobby.
  Reply With Quote
Old 7th June 2013, 04:48 PM   #63
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by jeronimo83 View Post
Bolserst, thanks very much for your illustrations....
(PS sorry for interrupting this thread.)
Glad I could help, and best of luck with your project.

This thread was started to share experiences with the ESL_SEG_UI simulator.
So, as WrineX mentioned, your questions were not an interruption at all.
I'm sure other readers will find the discussion useful.
  Reply With Quote
Old 11th June 2013, 09:29 PM   #64
diyAudio Member
 
Join Date: Dec 2012
Well I've rebuilt the electrostat with the help of your schematics bolserst and it's working like a charm. Seems to me I've got a nice flat frequency response and a little bit more spread too. Although I do lose a small bit of sound pressure, with the 90 watt amp I've bought recently it's not noticable.

I will now be finishing the subwoofers, which are going to be a dipole M shape. Will keep you posted when things are finished.
  Reply With Quote
Old 12th June 2013, 08:16 AM   #65
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
That is great !!!
Please post some pictures soon !!!

Cheers!!!


jer
  Reply With Quote
Old 26th June 2013, 04:44 PM   #66
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
In response to your question posted here:
Electrostatic speakers as microphones?

Quote:
Originally Posted by jeronimo83 View Post
Hi bolserst. Interesting measurements. I've currently made a 12 micron ESL and used the ESL_UI software (which you know well) to calculate segmentation resistors for a flat frequency response. Judging from your measurements, I need to equalize the high frequencies up to almost 9 dB with my diafragm thickness. Am I right? If so, I'd rather use different resistors to compensate for the diafragm roll off.
Hello jeronimo83,

The measurements showing -9dB at 20kHz are for 12 micron diaphragm alone. When stators are added around the diaphragm things get more complicated. There is now a response boost from the cavity formed between the stators and diaphragm. The exact nature of the boost(frequency and magnitude) will depend on the diaphragm to stator spacing(D/S), stator thicknes, and % open area of the stators. With typical ESL wire stator construction and D/S= 1.5mm - 3mm you can expect about 3dB - 4dB boost in the 10khz - 20kHz range. However, it is best to measure your ESL to find out for sure.

In general, it is recommended to use diaphragm thickness 6 micron or thinner to avoid having to use EQ to compensate for HF roll off. You can't really compensate for this HF roll off with the segmentation resistors since at most they can affect a +3dB/oct slope where as the roll off is a -6dB/oct slope. Also, efficiency would suffer.

However, all is not lost. You can use the resonance between your transformer leakage inductance and ESL capacitance to boost the response to compensate for the HF roll off from diaphragm mass. The center frequency for the boost is fixed by your transformer design, but you can control the magnitude of the boost by varying the resistance in series with the transformer primary. Since you currently have a 1 ohm resistor in series with the primary, you might try changing it to 1/2 ohm to see if you like the sound of the HF balance better. As already mentioned, it is best to measure your ESL to determine what actual response is.

Links to two example trend plots of transformer response with varying resistance in series with primary.
Response for your specific transformer will be different, but damping trends will be similar.
Step-up transformer design (see attachment 3)
ESL hybrid (see attachment 2)

What transformer are you using to drive your ESL?
  Reply With Quote
Old 28th June 2013, 12:02 PM   #67
diyAudio Member
 
Join Date: Dec 2012
Quote:
Originally Posted by bolserst View Post
In response to your question posted here:
Electrostatic speakers as microphones?



Hello jeronimo83,

The measurements showing -9dB at 20kHz are for 12 micron diaphragm alone. When stators are added around the diaphragm things get more complicated. There is now a response boost from the cavity formed between the stators and diaphragm. The exact nature of the boost(frequency and magnitude) will depend on the diaphragm to stator spacing(D/S), stator thicknes, and % open area of the stators. With typical ESL wire stator construction and D/S= 1.5mm - 3mm you can expect about 3dB - 4dB boost in the 10khz - 20kHz range. However, it is best to measure your ESL to find out for sure.

In general, it is recommended to use diaphragm thickness 6 micron or thinner to avoid having to use EQ to compensate for HF roll off. You can't really compensate for this HF roll off with the segmentation resistors since at most they can affect a +3dB/oct slope where as the roll off is a -6dB/oct slope. Also, efficiency would suffer.

However, all is not lost. You can use the resonance between your transformer leakage inductance and ESL capacitance to boost the response to compensate for the HF roll off from diaphragm mass. The center frequency for the boost is fixed by your transformer design, but you can control the magnitude of the boost by varying the resistance in series with the transformer primary. Since you currently have a 1 ohm resistor in series with the primary, you might try changing it to 1/2 ohm to see if you like the sound of the HF balance better. As already mentioned, it is best to measure your ESL to determine what actual response is.

Links to two example trend plots of transformer response with varying resistance in series with primary.
Response for your specific transformer will be different, but damping trends will be similar.
Step-up transformer design (see attachment 3)
ESL hybrid (see attachment 2)

What transformer are you using to drive your ESL?
Thanks for your extensive reply. I realize the thickness of the mylar I used has disadvantages and I might have chosen otherwise. Anyway, this type of mylar was freely available and also had an aluminium layer damped onto it, so I didn't have to fiddle around with membrane coating. Everything is a first in this building project so I tried to minimize the difficulties.

I understand now that I won't be able to get the most out of my project without measuring frequency response when it's finished. I don't have any experience in doing that also and was hoping to avoid it

I think I'll keep the 1 ohm resistor in series with the primary in place and see what it does. I have 4x 230v - 6v toroidial transformers per ESL for a total step up of 1:150. I have no exact core dimensions etc. but here are some pictures of the transformers currently attached to the subwoofer cabinet of one of the ESL's.
Attached Images
File Type: jpg IMG_20130628_125652.jpg (506.9 KB, 189 views)
File Type: jpg IMG_20130628_125639.jpg (448.2 KB, 175 views)
  Reply With Quote
Old 29th November 2013, 03:46 PM   #68
diyAudio Member
 
Join Date: Jan 2006
Location: netherlands
Quote:
Originally Posted by bolserst View Post
“esl_seg_ui” is a program written by Edo Hulsebos for modeling segmented line source ESLs.
I think you can still download a copy at the following link:
http://www.edohulsebos.nl/apps/esl_seg_ui.part01.exe
Nice to see that my simple program is of use here! I attached the Matlab source code of the program.

Edo
Attached Files
File Type: zip esl_seg_ui.zip (9.4 KB, 36 views)
  Reply With Quote
Old 29th November 2013, 04:21 PM   #69
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
Quote:
Originally Posted by hulsebos View Post
Nice to see that my simple program is of use here! I attached the Matlab source code of the program.

Edo
it is verry much so! thank you for all the work!
  Reply With Quote
Old 30th November 2013, 12:15 PM   #70
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
hulsebos, Thank You very much for your contribution!!!!

I can now try to learn how it works sometime !!!

This is such a great program you have written however simple it may be!!!

Thanks Again!!!

jer
  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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ESL stator rho Planars & Exotics 13 4th January 2008 11:37 PM
ESL stator fixing 405man Planars & Exotics 9 29th August 2007 11:19 PM
Wire Insulation for Wire stator Audio_idiot Planars & Exotics 6 25th May 2007 12:42 PM
single stator esl. tade Planars & Exotics 2 4th July 2005 06:00 PM
angles for segmented ESL? Few Planars & Exotics 21 25th February 2005 04:30 PM


New To Site? Need Help?

All times are GMT. The time now is 05:21 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2