fullrange dipole with Qts 0.25 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 17th July 2005, 04:10 PM   #1
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
Default fullrange dipole with Qts 0.25

Hello all!

My task was to build something that sounds like an open baffle but doesn`t need that much space. And now I managed to build a dipole from a Qts 0.25 driver standing directly in front of the wall. Pictures of my design will follow soon, but first I want to know whether there is anybody else who managed to get bass out of a Qts 0.25 driver in a dipole.

Greets, Oliver
  Reply With Quote
Old 17th July 2005, 06:57 PM   #2
diyAudio Member
 
Join Date: Oct 2001
Hallo Oliver,
you should try a currentsource or add a large resistor in series with the output of your amp (you will loose some power ca. 12 Ohm).
So bette go for a current source.
Andreas
  Reply With Quote
Old 17th July 2005, 07:54 PM   #3
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
Hi Oliver,
there seems to be a common misperception regarding the Qts of a driver when used for Open Baffle. A lower Qts (0.25) only means that you will require more eq than a high Qts driver to maintain a flat response. It has absolutely nothing to do with "how much" bass can be produced. That is determined by other factors, such as the drivers Sd, xmax and the path length difference for your acoustic short circuit. You made no mention of these for your driver.
Another common issue for those who want OB (dipole) but lack the space to do so, is control of your rear wave. One possibility is to heavily treat the area behind the speaker, if it is to be relatively close to the rear wall. This can be effective for upper frequencies, but less effective for the lowest. You could try an OB that does not extend too low in frequency, then use a sub for the lowest.
Another alternative is a cardioid. Using a u-shaped baffle and acoustic absorbers to reduce the resulting resonance peak. Gradient uses this method in their speakers. John K uses a cardioid sub for his NaO design.
Good luck and please post some pics of what you have done.

Cheers,

AJ
  Reply With Quote
Old 18th July 2005, 02:34 PM   #4
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
And now I managed to build a dipole from a Qts 0.25 driver standing directly in front of the wall.
Greets!

FYI, you created either a BR or TL depending on the baffle's dims, not dipole. Position them well away from the walls/corners to make them dipoles and hear your LF disappear due to the low Qts.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 18th July 2005, 03:42 PM   #5
Rudolf is offline Rudolf  Germany
diyAudio Member
 
Rudolf's Avatar
 
Join Date: Mar 2003
Location: Germany
Default Re: fullrange dipole with Qts 0.25

Quote:
Originally posted by el`Ol
I want to know whether there is anybody else who managed to get bass out of a Qts 0.25 driver in a dipole.
Hi Oliver,

My personal record holder is Timo alias "tiki", who built a W-frame dipole sub with two Isophon PSL 385/400. Qts=0,17

Timo has documented his dipole here (sorry, its all German ):
http://www.hifi-forum.de/index.php?a...ack=&sort=&z=2

Another guy putting his OBs against the wall is another Timo, who presents his "SOS" in the Visaton forum (again German spoken only):
http://www.visaton.de/vb/showthread....threadid=10090

So it seems your approach is a very "teutonic" one
__________________
www.dipolplus.de
  Reply With Quote
Old 18th July 2005, 04:54 PM   #6
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
Here..
Attached Images
File Type: jpg hauke1.jpg (16.6 KB, 495 views)
  Reply With Quote
Old 18th July 2005, 04:55 PM   #7
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
are..
Attached Images
File Type: jpg hauke2.jpg (18.3 KB, 473 views)
  Reply With Quote
Old 18th July 2005, 04:56 PM   #8
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
..the pictures.
Attached Images
File Type: jpg hauke3.jpg (15.7 KB, 441 views)
  Reply With Quote
Old 18th July 2005, 05:03 PM   #9
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
The speakers are attached to the wall. Angle is 30. Drivers are FE126E. They sound like OB, not like BR or TL. The 2/3 tube forms some kind of horn. Bass is ok, I don`t find a sub necessary. Unfortunately the treble is far behind my Ciares, I would try the Supravox 135LB instead of the Fostexes next time.
  Reply With Quote
Old 18th July 2005, 06:20 PM   #10
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
Wow, that close to the wall! That setup looks more like some sort of TL ,venting at the top, I can't see OB there. Is the cylinder solid? The only scenario I can think of in that situation would be a flat panel baffle with your driver and lots of acoustic absorbtion on the wall behind. The frequency range of that tiny driver won't extend too low, where the absorbers have the least effect. Good luck!

Cheers,

AJ
  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 Ribbon tweeter isolation from dipole mid-woofer array Bent Planars & Exotics 5 21st May 2009 12:10 PM
(WW) MMTMM dipole 4 vs 3 way / dipole benefit frequencies? charliemouse Multi-Way 25 7th July 2007 11:19 PM
Designing a fullrange dipole? Kensai Full Range 10 6th January 2006 03:49 PM
When is a dipole not a dipole anymore? Bas Horneman Multi-Way 5 5th December 2003 03:02 PM
Fullrange IB with Dipole Sub taufern Multi-Way 16 1st June 2003 01:24 AM


New To Site? Need Help?

All times are GMT. The time now is 11:10 PM.


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