Dynapleat - 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 11th February 2009, 02:36 PM   #21
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
...um a Q of 0.8 is not overdamped at all.

0.707 is called "critically damped" and the range between that and 0.5 is generally considered optimal damping for a filter. But speakers are a little different.

In a dipole speaker 0.8 is good, since there is no cabinet with an air mass to interact. Even 1.0 is ok fine. Gets you a bit more bass in the real world.

But, if there is overlap between the -3dB point acoustically of the dynapleat in the baffle and the subwoofer, then some adjustment is in order with either the sub's xover point/slope and/or the dynapleat's roll-in - which would imply a high pass.

However, things would likely sound best phase wise without an xover, but again that depends on the phase relationships between the drivers around the xover point anyhow.

Using a high pass will REDUCE the excursion of the dynapleat due to LF energy that does not produce usable output, and so increase the power handling, thus it is not a bad idea in practice,especially if you want to play them loudish.

_-_-bear
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 11th February 2009, 04:04 PM   #22
des1a is offline des1a  United States
diyAudio Member
 
Join Date: Feb 2009
Default greetings bear

Actually, I think critical damping is defined as a Q of unity. Conventional wisdom says that the optimum damping of a cone driver in an enclosure should be .707 due to the overhang that occurs with most relatively massive woofers.

When I built my system, I knew I was going to use a biamped subwoofer and could adjust that crossover point to fine-tune the low end. As you say, a high-pass filter could affect phase response in the mid and upper bass and I preferred to avoid any possible loss of coherency in the range of the Dynapleats. In that overlap region, however, there are probably many things going on. I admit to some luck in getting a result that seems "just right".

I haven't detected any lack of control in the Dyanpleats, even at higher listening levels. The perforated sheet introduces what is called a mixed-mass resistive element not unlike a resistive port in a reflex enclosure. It provides some frequency dependent damping, greater at the low frequencies.
  Reply With Quote
Old 12th February 2009, 10:13 PM   #23
diyAudio Member
 
Join Date: Feb 2003
Location: Québec
Default Re: greetings bear

Quote:
Originally posted by des1a
As you say, a high-pass filter could affect phase response in the mid and upper bass and I preferred to avoid any possible loss of coherency in the range of the Dynapleats. In that overlap region, however, there are probably many things going on. I admit to some luck in getting a result that seems "just right".
I had not thought about the phase shift that would be induced by the high pass filter into the midband.. Makes sense.

All is missing now is some spare time to get my hands again on these drivers and make some experiments..
__________________
Sylvain, Québec
  Reply With Quote
Old 14th March 2009, 06:29 PM   #24
des1a is offline des1a  United States
diyAudio Member
 
Join Date: Feb 2009
Default Crossover addendum

In case you're getting close to buying the coils (inductors) or winding them yourself, I wanted to mention that I changed the values on mine and prefer the newer version. I changed the .6mH to 1.5mH and changed the .3mH to .6mH. The overall sound is now a bit less hard in the upper midrange when the music has a lot of energy in the lower treble range.

I wanted to post this before they make changes in the website. My experience is that website changes usually give me a real headache since I use a non-standard browser.

regards, and I hope you're making progress.
  Reply With Quote
Old 1st June 2009, 11:26 AM   #25
marcusb is offline marcusb  Canada
diyAudio Member
 
Join Date: Jun 2009
Sylvain can you please send me an email.
Thanks
  Reply With Quote
Old 1st June 2009, 09:44 PM   #26
diyAudio Member
 
Join Date: Feb 2003
Location: Québec
Default Email to MarcusB

Hi Marcus, I've tried to email you via this site, but I get a message saying that your account is set up in a way that doesn't allow emailing directly to you..
Sylvain
__________________
Sylvain, Québec
  Reply With Quote
Old 2nd June 2009, 02:02 PM   #27
marcusb is offline marcusb  Canada
diyAudio Member
 
Join Date: Jun 2009
Default dynapleats

Hi again,

This is the email i can be reached mbienv@pacocorp.com

Thanks

Marc
  Reply With Quote
Old 4th June 2009, 01:03 AM   #28
diyAudio Member
 
Join Date: Feb 2003
Location: Québec
Default Email

Hi friend,

I've sent you an email yesterday. Hoping you got it. Check in your spam messages as well. Some software just delete unknown emails.

Bye
__________________
Sylvain, Québec
  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



New To Site? Need Help?

All times are GMT. The time now is 04:47 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