On the directivity of dipole tweeters - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

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 22nd February 2010, 02:38 PM   #11
Rudolf is offline Rudolf  Germany
diyAudio Member
 
Rudolf's Avatar
 
Join Date: Mar 2003
Location: Germany
Quote:
Originally Posted by mondogenerator View Post
mow i need to learn more German so i can try an do some interesting sims too as i only use as much as i understand in german language
I'm taking my hat off to any foreigner who is trying to understand Boxsim in German!
The text in Boxsim would be foreign language for most Germans too.
There has been some initiative to get an english version of Boxsim. Trouble is that the complete text is imbedded in the code - no separate language database. So UweG - the coder - shies away from excising all those textstrings.
__________________
www.dipolplus.de
  Reply With Quote
Old 22nd February 2010, 06:24 PM   #12
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally Posted by keyser View Post
...
Perfect dipole treble seems impossible in the real world
...
With distributed mode transducers one can get larger than wavelength
without beaming. Dipole radiation is a natural way to use a DML.


Kind regards
__________________
Oliver, RFZ believer (?)
www.dipol-audio.de
  Reply With Quote
Old 22nd February 2010, 07:47 PM   #13
Rudolf is offline Rudolf  Germany
diyAudio Member
 
Rudolf's Avatar
 
Join Date: Mar 2003
Location: Germany
Default A man has to do what a man has to do ...

Am I completely nuts?

Click the image to open in full size.

I cut the front plates of two Dayton ND20FA to the minimum and glued them roughly together without any baffle. You can compare the size to the previous baffle above. Dipole length now is 3.1 cm.

Then the same horizontal measurement procedure as before:

Click the image to open in full size.

Since I could not believe what I saw, I did the same for the backside of the dipole tweeter and moved to the other 90deg side:

Click the image to open in full size.

Green lines are for power response. Don't know why the 75deg response for the first diagram did not come up like that for the second series.

Tell me that this can't be true. Both drivers together are under 19 Euro. One BG Neo3 is 79 Euro in Germany.
Attached Images
File Type: jpg DaytonND20 b2b_2.JPG (32.8 KB, 1205 views)
File Type: gif DaytonND20 tinyb2b_1.gif (26.4 KB, 2010 views)
File Type: gif DaytonND20 tinyb2b_2.gif (24.9 KB, 1505 views)
__________________
www.dipolplus.de
  Reply With Quote
Old 22nd February 2010, 08:43 PM   #14
diyAudio Member
 
Join Date: Mar 2008
Hello Rudolf,

this is a really impressing - and cost efficient - result !

For vertical angles i would expect some more disturbances,
but when that configuration is mounted at the right height
that should be neglegible in practice.

Kind regards
__________________
Oliver, RFZ believer (?)
www.dipol-audio.de
  Reply With Quote
Old 23rd February 2010, 02:31 AM   #15
diyAudio Member
 
Join Date: Sep 2002
Location: Oregon, USA
Wow, that's really impressive. And just when we'd all agreed that dipole up to 20kHz was impossible
  Reply With Quote
Old 23rd February 2010, 04:03 AM   #16
diyAudio Member
 
Join Date: Dec 2002
Location: Planet Earth
Nice Rudolf! Can you remove the front plate from the ND20 to cut it down or do you just mask off the dome and cut it?
__________________
Dennis H
  Reply With Quote
Old 23rd February 2010, 07:34 AM   #18
diyAudio Member
 
jerome69's Avatar
 
Join Date: Feb 2008
Location: Lyon
Quote:
Originally Posted by Rudolf View Post
One BG Neo3 is 79 Euro in Germany.
You can get it for 49 in France
It is rare that things are cheaper in France.
  Reply With Quote
Old 23rd February 2010, 09:49 AM   #19
Rudolf is offline Rudolf  Germany
diyAudio Member
 
Rudolf's Avatar
 
Join Date: Mar 2003
Location: Germany
Quote:
Originally Posted by Saurav View Post
Wow, that's really impressive. And just when we'd all agreed that dipole up to 20kHz was impossible
Yeah. When I started with cutting the drivers front plate, I expected to push that dipole irregularity 0.5 kHz up at the upmost. Really did not expect it to almost vanish. But obviously those last mm can make a vast difference.

Quote:
Originally Posted by catapult View Post
Can you remove the front plate from the ND20 to cut it down or do you just mask off the dome and cut it?
Click the image to open in full size.
No removable front plate. But you can easily saw or cut around the magnet housing from the backside. Quite soft plastic, no danger of anything chipping away. I did mask off the dome, yes.

Instead of simply glueing the drivers together - as I did - it could be a good idea to make a pair of mounting flanges like this:

Click the image to open in full size.

Quote:
Originally Posted by CLS View Post
Will this be a little more 'convenient':
Dayton ND16FA-6 5/8" Neodymium Dome Tweeter
or ... Dayton ND20FB-4 Rear-Mount 3/4" Neodymium Dome Tweeter
Not really. The ND16FA is just a 16 mm instead of 20 mm dome in a housing of the same size. That is no deal IMHO.
The ND20FB-4 is larger in both directions. Both tweeters have more of a waveguide in front than the ND20FA. I fear that they might develop some sort of horn directivity before the dipole directivity disappears.

Quote:
Originally Posted by jerome69 View Post
You can get it for 49 in France
It is rare that things are cheaper in France.
Thank you, nice to know. The German import only sells a special PDR-I version.
Quote:
Originally Posted by LineArray View Post
Hello Rudolf,
For vertical angles i would expect some more disturbances,
but when that configuration is mounted at the right height
that should be neglegible in practice.
The vertical distance of the drivers is 2 mm less than in the previous version. So the vertical balance should be no worse than before. I will do new measurements some time this week.

Thanks to everybody for your appreciation of my work
Rudolf
Attached Images
File Type: jpg DaytonND20_3.JPG (4.3 KB, 1170 views)
File Type: gif DaytonND20FA_2.gif (3.1 KB, 1171 views)
__________________
www.dipolplus.de
  Reply With Quote
Old 23rd February 2010, 01:05 PM   #20
sendler is offline sendler  United States
diyAudio Member
 
Join Date: Aug 2004
Location: ny
Default Crossover point?

That is a great pattern but how much of the already minimal power handling and low frequency extension will remain after EQ to even make it to a 3k crossover?
__________________
Scott
  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
Dipole tweeters firestorm Multi-Way 19 7th February 2010 02:18 AM
FS: Linaeum/Tandy Dipole Tweeters rabidlistener Swap Meet 3 27th July 2007 11:16 AM
FS: 1 pair of aura / linaeum dipole ribbon tweeters zobsky Swap Meet 9 13th September 2006 10:46 PM
Blending controlled directivity treble with dipole midrange? 454Casull Multi-Way 21 17th September 2005 01:28 AM
Set of 4 Optimus Linaeum Dipole Tweeters on Ebay The Paulinator Swap Meet 1 13th July 2005 07:30 AM


New To Site? Need Help?

All times are GMT. The time now is 03:28 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