diy esl suggestions thread - Page 3 - 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 February 2007, 07:42 PM   #21
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

well I could easily measure the difference and even more...its clearly audible imo in that way that with the linesource You can walk through the room and You have the impression of a more constant loudness. Especially when You aproach the source (nearfield conditions) the difference becomes very obvious, because the linesource doesn´t get louder but it is indeed getting softer. Of course won´t You measure the complete theoretical +3dB, but the difference is there.

As Brian already pointed out, it is relatively easy possible to get linesource conditions for the bass. Its just a matter of the height of the speaker and the floor-ceiling-distance.

I had for example the problem of very serious roommodes in vertical direction that made listening nearly impossible. The typical small dipole bass wouldn´t help here even when it was already better suited to the room than other basses. The solution came when I built the bass-tower. It very obviously excites the vertical modes far less.
And while the bass is not beaming like the higher freqs, You can clearly hear and measure the dipolar distribution character.
And I must say I´m most happy that this ´antiphase sound is causing a lot of trouble´ ...I´m spending now too much time in front of them listening and just having one goosebump after the other :-)

jauu
Calvin

ps:
@MJ.....Are these personal assumptions or do you have any experience with well built dipol basses?
  Reply With Quote
Old 6th February 2007, 11:04 PM   #22
diyAudio Member
 
Join Date: Apr 2005
Location: Utrecht
Quote:
Originally posted by Calvin
Hi,


ps:
@MJ.....Are these personal assumptions or do you have any experience with well built dipol basses?

Hi,

Nice one!

I just wanted to make clear that the theories describing the propagation of sound are based on a theoretical model which has nothing to do with domestic conditions. Of course my style of writing is a bit incisive, provoking some discussion here, so don't take it personal.

I have built around four pairs of full range dipole esls. 1,85 to 2,0 meter high. So not from floor to ceiling (almost none of the esls I've seen are from floor to ceiling, except some 240 cm high ESLs build by Fikier which doesn't fit in his new house with its lower ceiling). The response of one of the largest ESL was measured and showed a suck-out between 100 and 200 Hz roughly. I have listened for many years to this speakers. They had their obvious strengths but the suck-out was annoying; most of all after switching from headphones to the ESLs which I frequently did. Some of the warm Fender sounds simply dissapeared in case of the ESLs. I have seen similar behaviour in the measurements of large Final1.2 ESLs.
__________________
drs M.J. Dijkstra
  Reply With Quote
Old 7th February 2007, 08:33 AM   #23
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

don´t worry MJ....a bit of provocation livens up an otherwise boring thread sometimes. I like that

The suckout prob is really a matter of any open baffle. With my hybrid I have to correct just slightly for this effect by letting the HP-filter have a bit more gain, but without correction it sounds a bit thin (together with the ´wings´ beeing ~45cm wide the cancellation starts at ~600Hz).
The folded shapes for the woofers behave differently as You can see from the measurements below.
Thats what I like about this system. You don´t need to equalize very much, thereby conserving a large dynamic headroom for the panel and the dipole sub fills up the rest of the spectrum nicely to the lower freqs. Sonically I can´t hear any transition artifacts between bass and panel. It sounds like a fullranger ESL, but without the tendency of thinning and with considerably greater efficiency and dynamics. And the size of the system isn´t that different to a big FR-ESL. either

jauu
Calvin
  Reply With Quote
Old 7th February 2007, 12:31 PM   #24
diyAudio Member
 
Join Date: Apr 2005
Location: Utrecht
Hi Calvin,

Sounds interesting!
What's the lowest frequency you get with the dynamic dipole?
What power do you need at that frequency?
Don't you have some problems (suckout) when placed closed to the backwall?

Best regards, MartinJan
__________________
drs M.J. Dijkstra
  Reply With Quote
Old 7th February 2007, 06:52 PM   #25
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

the 6.5" drivers I use have an free air Fs of ~42Hz that sinks after build-in down to 35Hz. I need a slight bass boost that I realize with a subsonic filter in the active crossover. With the parameters of this boost You can fudge a bit with the lower cutoff freq, but You can reach 30Hz without equalizing and stressing the drivers too much.
I drive them with a 100W amp and wire the 8 drivers per side to give >8 Ohms since the amp is rather an 8Ohm design. The amp is nearly able to drive the speakers to full excursion and efficiency of the system fits nicely to the second amp driving the ESL. Still I intend to build some more powerful D-amps in nearer future to have more reserves (clipping etc).

I didn´t test placing the towers close to the backwall, since they should stay in close proximity to the panels and I wouldn´t place those close to a wall anyway.

jauu
calvin
  Reply With Quote
Old 9th February 2007, 06:35 AM   #26
Zombie is offline Zombie  Sweden
diyAudio Member
 
Join Date: Feb 2003
Location: At home
Default Save yrself trouble

...build these: http://cgi.ebay.co.uk/ws/eBayISAPI.d...MakeTrack=true

You won't be dissapointed...
  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
need amp suggestions please. kendt Tubes / Valves 14 23rd February 2009 01:13 AM
Yet Another Phono Stage Suggestions Thread dsavitsk Tubes / Valves 34 20th November 2008 11:36 AM
sub amp- suggestions coz790 Solid State 0 9th January 2006 08:43 AM


New To Site? Need Help?

All times are GMT. The time now is 08:30 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