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

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

experiences with ESL directivity?
experiences with ESL directivity?
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 26th September 2016, 06:39 PM   #91
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
Quote:
Originally Posted by bolserst View Post
Remember that even though PVC is considered an insulator, it is MUCH more conductive than air both for DC bias voltage and AC stator signal voltage. The PVC bulk resistitivity and dielectric constant K are the determining properties. With this in mind when calculating SPL for wire ESLs built with PVC insulation, it is most appropriate to use the distance from the diaphragm to the outside of the insulation as D/S.

You can easily verify this by measuring the capacitance between the stators. You will find with varying insulation thickness, the capacitance measurement will correspond well with the flat plate capacitor calculation when you use the dimension between the outer diameter of the insulation, not the outer diameter of the copper conductor inside the insulation.
http://www.diyaudio.com/forums/plana...ml#post3881204

More discussion and examples on this topic can be found here:
http://www.diyaudio.com/forums/plana...ml#post2154621
http://www.diyaudio.com/forums/plana...ml#post4492011
oh wow, thats a nice feature. since it still protects against arcing and such, without losing the spacing to insulation? hmmm very nice !! does it also holds with perf sheets that have some laquer? or only for PVC ?
  Reply With Quote
Old 26th September 2016, 07:00 PM   #92
bolserst is offline bolserst  United States
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by WrineX View Post
oh wow, thats a nice feature. since it still protects against arcing and such, without losing the spacing to insulation? hmmm very nice !! does it also holds with perf sheets that have some laquer? or only for PVC ?
Indeed, PVC insulation has many desirable features for ESL stators, as outlined in the original JansZen patent that first promoted its use.
As far as coatings used on perf sheets, you would need to look at the electrical properties of the coating and compare them to PVC. In general, most coatings have as high a dielectric constant(good) as PVC, but not as low a bulk resistivity(bad) as PVC. Calvin mentioned in one thread that Nylon 66 is one particular coating that is as good if not better than PVC. Use of polyamide coatings such as nylon were also suggested in one of the Beveridge patents because of their low bulk resistivity.
  Reply With Quote
Old 26th September 2016, 07:17 PM   #93
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
Thanks again Bolserst for clarifying !still learning everyday

coating with nylon,
Fluidised Bed powdercoating should work i once looked into that but somehow i did not manage to get a nice Fluidised bed
to much interesting techniques
  Reply With Quote
Old 27th September 2016, 04:15 AM   #94
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

a coating functions like a second capacitor in series with the 'air-capacitor'.
As such they also form a voltage divider.
Thats the reason why low-k high-R materials cost on efficiency ... voltage loss over the dielectric,
When the k is high, the insulating layer can be made thicker, as the material acts like a field conductor, increasing field strength in the air capacitance, but still achieving high flashover tresholds due to its thickness.

Fluidized bed coating won't work with metal sheet stators ... at least not as single procedure.
The heat capacitance of a metal sheet is too low.
It cools down too fast for the powder to melt completely.
At least a additional heating/melting processes would be required with the problem of the coating beginning to flow again.
Its a process to produce thick coatings on big parts (offshore, oil rigs) that once heated keep the temperature over a longer time.

jauu
Calvin
  Reply With Quote
Old 23rd May 2018, 03:54 AM   #95
bolserst is offline bolserst  United States
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Here is Version 4 of the spreadsheet.
The following functionality was added based on feedback from users:
  • Parameter values now auto convert when you switch units.
  • Damping section has been expanded to allow specifying either resonance Q or acoustic resistance of damping mesh.
    Whichever parameter you specify, the other is calculated and displayed.
  • An estimate of peak diaphragm excursion is plotted for frequencies below fL where the entire diaphragm area is uniformly driven.
  • Response curves are now continuous rather than straight line approximations connecting the break points.
    Many thanks to golfnut for his math wizardry in deriving and simplifying the equations.
  • Added input to specify number of wires per section to use for the esl_seg_ui import data.
As with previous versions, each TAB is protected so you don't accidently mess up one of the formulas. There isn't a password though, so you can easily unprotect each TAB and change or rearrange things as you see fit. Changing any blue input cell, will re-protect the main input TAB.

Let me know if you have any questions or if something doesn’t seem to be working properly.
Attached Images
File Type: png ESL_line_sectioned_DIY_v4.png (98.6 KB, 147 views)
Attached Files
File Type: zip ESL_line_sectioned_DIY_v4.zip (334.1 KB, 35 views)

Last edited by bolserst; 23rd May 2018 at 03:57 AM.
  Reply With Quote
Old 23rd May 2018, 07:10 AM   #96
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
Quote:
Originally Posted by bolserst View Post
Here is Version 4 of the spreadsheet.
The following functionality was added based on feedback from users:
  • Parameter values now auto convert when you switch units.
  • Damping section has been expanded to allow specifying either resonance Q or acoustic resistance of damping mesh.
    Whichever parameter you specify, the other is calculated and displayed.
  • An estimate of peak diaphragm excursion is plotted for frequencies below fL where the entire diaphragm area is uniformly driven.
  • Response curves are now continuous rather than straight line approximations connecting the break points.
    Many thanks to golfnut for his math wizardry in deriving and simplifying the equations.
  • Added input to specify number of wires per section to use for the esl_seg_ui import data.
As with previous versions, each TAB is protected so you don't accidently mess up one of the formulas. There isn't a password though, so you can easily unprotect each TAB and change or rearrange things as you see fit. Changing any blue input cell, will re-protect the main input TAB.

Let me know if you have any questions or if something doesn’t seem to be working properly.
GREAT! thats a keeper ! might come in handy, thanks allot for all the hard works once again !
  Reply With Quote
Old 23rd May 2018, 10:15 AM   #97
bentoronto is offline bentoronto  Canada
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
experiences with ESL directivity?
Also opens and looks beautiful in Mac OSX both in "Excel" and in "Numbers" (which I almost always prefer). But I haven't confirmed all the functionality is functioning.

Of course, there are the usual warnings from Microsoft, buggy and otherwise. Excel for example warns "File error: Data may have been lost".

B.
__________________
HiFi aspirations since 1957. Currently working on motional feedback again... the final frontier in audio (and just posted data for a folded 17-foot pipe sub)

Last edited by bentoronto; 23rd May 2018 at 10:20 AM.
  Reply With Quote
Old 23rd May 2018, 04:10 PM   #98
CharlieM is offline CharlieM  United States
diyAudio Member
 
CharlieM's Avatar
 
Join Date: Feb 2008
Location: Savannah, GA
Quote:
Originally Posted by bolserst View Post
Here is Version 4 of the spreadsheet.
Let me know if you have any questions or if something doesn’t seem to be working properly.
I need a sanity check on my interpretation of the LF break point and it's correlation to the crossover frequency in a hybrid application:

Is it correct to say that the LF break point is effectively the upper frequency limit of the last segment in the transmission line (i.e... the last wire group(s) in the series)?

If so; the crossover frequency should be lower than the LF break point; else the crossover would chop off the signal above the upper limit of the latter wire group(s) in the series.

Did I get that right?

Lastly; can you recommend some general guidance as to where the crossover frequency needs to be in relation to the LF break point (or visa versa)?

Last edited by CharlieM; 23rd May 2018 at 04:27 PM.
  Reply With Quote
Old 23rd May 2018, 10:23 PM   #99
bolserst is offline bolserst  United States
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by bentoronto View Post
Also opens and looks beautiful in Mac OSX both in "Excel" and in "Numbers" (which I almost always prefer). But I haven't confirmed all the functionality is functioning.
Unfortunately you will find "Numbers" does not handle the VBA code properly.
You should be able to use Version 2 of the spreadsheet just fine though as it has no VBA code.

Quote:
Of course, there are the usual warnings from Microsoft, buggy and otherwise. Excel for example warns "File error: Data may have been lost".
As much as I like to complain about Microsoft and Apple software, I believe that error is due to uninstalled service packs. The spreadsheet may work just fine even with the error...can't tell you for sure though. If you let me what version of Excel you are running, I can email you a copy saved for that version that should open up fine.
  Reply With Quote
Old 23rd May 2018, 11:02 PM   #100
bolserst is offline bolserst  United States
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by CharlieM View Post
…the crossover frequency should be lower than the LF break point; else the crossover would chop off the signal above the upper limit of the latter wire group(s) in the series. Did I get that right? …can you recommend some general guidance as to where the crossover frequency needs to be in relation to the LF break point (or visa versa)?
Sounds like you got it right. Basically fL is the frequency at which all segments or groups of wires have achieved their maximum SPL contribution. The last segment is the last to have its output rolled in, but the final octave shows all segments reaching there maximum output pretty much together. The upper plot in the esl_seg_ui window shows the magnitude of the voltages applied to each of the individual segments by the ladder resistor network. You can see that at fL, all segments are receiving full voltage, and the response has started to follow the -3dB slope of a dipole line source ESL. So, if you set fL lower than fX(crossover frequency) you will just be throwing away sensitivity.

General guidance is to set fL = fX, or at most fL = fX * 1.15.
If your diaphragm resonance is undamped and within 1.5 octaves of fX, you will see some response lift at fX from the resonance. So, you could move fL up in frequency by as much as a factor of 1.5 and gain 1 - 2dB of efficiency while retaining the response level at fX. Of course with resonance so close to fX you would need to use a notch filter in combination with the crossover to avoid over driving the diaphragm at resonance. I seem to recall you already having experience with this.

***
Found what I was thinking of: Thinking about a segmented wire stator ESL - Post#186 & #187
Attached Images
File Type: png fL_for_Fx.png (208.9 KB, 95 views)

Last edited by bolserst; 23rd May 2018 at 11:16 PM.
  Reply With Quote

Reply


experiences with ESL directivity?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
Constant Directivity Horn EQ Horizons Multi-Way 4 19th December 2008 11:41 AM
Constant directivity EQ Saurav Multi-Way 11 19th May 2008 02:41 AM
Constant directivity horn - or waveguide? hasselbaink Multi-Way 6 1st April 2008 01:24 PM
A question on directivity swak Multi-Way 18 31st July 2005 03:03 PM
Open baffles and directivity Yuihb Multi-Way 18 27th February 2004 08:22 PM


New To Site? Need Help?

All times are GMT. The time now is 10:48 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki