ESl speakers - why no cabinet? - 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 1st October 2008, 06:48 PM   #1
diyAudio Member
 
Join Date: Mar 2007
Default ESl speakers - why no cabinet?

Just curious: if one problem with ESL speakers is bass response due to cancellations from rear waves, why not build a box for the ESL speakers? Isn't that what a box is for? I'm baffled. (*rimshot* ... sorry.)
__________________
Everything I need to know I learned from catching smart people and eating their braaaaains...
  Reply With Quote
Old 1st October 2008, 07:52 PM   #2
diyAudio Member
 
Join Date: Aug 2008
We could but the cabinet would be very large and most think it would be unattractive in any room.
  Reply With Quote
Old 1st October 2008, 08:31 PM   #3
diyAudio Member
 
Join Date: Jan 2007
Location: Florida
You would lose the advantage of the speaker being a dipole line source.
  Reply With Quote
Old 1st October 2008, 09:02 PM   #4
diyAudio Member
 
Join Date: Mar 2007
Default Thanks for the responses

Thanks for the responses so far and forthcoming.

And what is the advantage of a dipole line source?

Thanks,
D
__________________
Everything I need to know I learned from catching smart people and eating their braaaaains...
  Reply With Quote
Old 1st October 2008, 10:04 PM   #5
diyAudio Member
 
Join Date: Jan 2007
Location: Florida
look here for more info on advantages and disadvantages: wikipedia.org/wiki/Electrostatic_speaker

Although I never tried 'boxing in' my electrostatic speakers, I would think you will lose some transparency as well.
  Reply With Quote
Old 2nd October 2008, 02:55 AM   #6
diyAudio Member
 
Join Date: Aug 2008
With any cabinet you will have resonances to deal with.

A dipole source can be good in combination with a beam splitter, you could just use the back wall corner behind the speaker. The reflected waves will combine with the front waves. This can in most cases cause destructive interferences (in the low end) but help support mids and highs.

To isolate the back from the front without the use of a cabinet try making a baffle, what you mount the cell into much much larger then the cells driven area.

happy building
bry
  Reply With Quote
Old 2nd October 2008, 05:11 AM   #7
diyAudio Member
 
Join Date: Mar 2007
Default Great stuff. Thanks!

I guess looking into the disadvantages of a box would have answered my questions somewhat.

Thanks again, all.
__________________
Everything I need to know I learned from catching smart people and eating their braaaaains...
  Reply With Quote
Old 2nd October 2008, 10:00 AM   #8
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

ElZombre You have to distuinguish between a working principle (ESL or dynamic speaker) and the way the membrane is coupled to the surrounding air.
Basically there´s nothing to say against putting an ESL into a cabinet, since it works like a mass-spring-system, similar to the dynamic speaker! This has been done for example by Beveridge.

But while the mass of a dynamic speaker is relatively large, the mass of a ESL-diaphragm is very small. So apart from ridicoulously low membrane tension (low spring rates) the ESL would show high Fs-values. Its lower Bandwidth limit would be too high --> no bass.
The Alternative would be to lower the spring rate of the cabinet, which means more volume and larger size and leads to other practical problems.

The very thin membrane is acoustically transparent over the complete audio frequency range. So any reflection coming from within the cabinet would pass the membrane without any attanuation. A reflection-free cabinet would have to be very deep (think of the Nautilus-concept of Bowers&Wilkins). Anyway the cabinet for a ESL would have to be built different than that for a dynamic speaker and it would have to be impractically large.

Since a ESL cannot develop as much power per area of membrane unit like a dynamic speaker, its membrane area must be larger to achieve the same acoustic power. A large membrane though is clearly advantageous when it comes to the degree of coupling to the air. The ´energy-transfer´of a large membrane to air is far better than that of a small membrane. The typically small membranes of a dynamic speaker are so mismatched to the surrounding air that it needs a cabinet to beef up (match) the performance. ESL membranes can be of a size and shape that allows ideal coupling to the air. So no cabinet at all is needed with regard to this point.

A open system suffers from acoustic phase cancellation which reduces the bass level. Again the ESL counters this by large membrane area and its shape. Using dynamic speaklers you need as well large membrane areas, which is why most open baffle speakers use multiple bass drivers.
The open baffle alters the distribution character, i.e. the way sound energy is spread over the room. This leads to a different, typically very precise and ´boomless´ and natural sounding bass that suits the exceptional qualities an ESL is capable in the mid-and high-frequency range very well.

You could place the ESL in a cabinet and gain something, but you would loose on other things. So in this ´compromise-game´ most designers opt for the open system.

jauu
Calvin
  Reply With Quote
Old 2nd October 2008, 11:20 AM   #9
diyAudio Member
 
Join Date: Apr 2005
Location: Utrecht
Hi,


I once put a very large sewer pipe (cut across its length) behind the esl. This way, I created a small enclosure with non-parallel walls with open ends at top and bottem. Some BAF wadding was used as well. Despite being open, this killed bass. I quickly removed this enclosure. I didn't experiment any further with enclosures as they probably will become unacceptable large.
I've heard someone build a quad57 in a wall with the room behind acting as an enclosure and that would sound great.
__________________
drs M.J. Dijkstra
  Reply With Quote
Old 2nd October 2008, 07:46 PM   #10
diyAudio Member
 
Join Date: Aug 2004
Location: Italy
Hi,

http://www.janszenloudspeaker.com/

interesting hibryd

Cheers,

Paolo
  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
speakers for a wierd cabinet sky12345 Multi-Way 15 13th November 2008 04:48 PM
6x9 FR speakers - what cabinet size? Simpleton Multi-Way 3 15th December 2005 09:38 AM
Bullfrog cabinet speakers Midwestchopshop Multi-Way 0 12th November 2005 10:49 PM
cabinet builders -- will these speakers fit? Dave Jones Multi-Way 3 23rd October 2004 06:04 AM
Sealed cabinet speakers Zepper Multi-Way 3 21st May 2004 12:34 PM


New To Site? Need Help?

All times are GMT. The time now is 08:38 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