Need some help designing a low pass filter. - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 27th July 2010, 01:55 PM   #11
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 96
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by rikvancoolwijk View Post
when you put a right and a left signal in the diferen vc's and the signal is is stereo (diferent per chanel) you will rip the woofer apart.
Where did you learn this? Sounds complete nonsense to me so I'm curious to know how you came by the idea...
__________________
It doesn't have to take the form of a conspiracy, rather a consensus... James H Kunstler
  Reply With Quote
Old 27th July 2010, 02:17 PM   #12
cbj591 is offline cbj591  United States
diyAudio Member
 
cbj591's Avatar
 
Join Date: May 2010
Boscoe

Correct - You will know if the voice coils are connected correctly right away. Low to no bass = Out of Phase.
  Reply With Quote
Old 27th July 2010, 02:23 PM   #13
Boscoe is offline Boscoe  United Kingdom
diyAudio Member
 
Join Date: Feb 2010
Location: England
Thanks great help! Now does anyone know where I can get 100Wrms kit amps in the UK?!!
  Reply With Quote
Old 27th July 2010, 03:02 PM   #14
epa is offline epa  Netherlands
diyAudio Member
 
Join Date: Apr 2010
Location: amsterdam
Quote:
Originally Posted by abraxalito View Post
Where did you learn this? Sounds complete nonsense to me so I'm curious to know how you came by the idea...
just my 2 cents.
dual vc are intended especialy 4 this purpose
just make sure they are in phase
  Reply With Quote
Old 27th July 2010, 03:43 PM   #15
diyAudio Member
 
Join Date: Sep 2008
Bass is not always in phase so you run the possibility if wasting energy and melt it (if they are out of phase at that point).
It should not however tear it self apart due to former being quite strong and made to handle the force generated in normal use.
But you never know if we are talking about cheap speakers.

Signal variant BL and Qes would be a little unpredictable one would expect. And back EMF could be dissipated by the other channel/amp if the signals differed.
  Reply With Quote
Old 28th July 2010, 01:53 AM   #16
cbj591 is offline cbj591  United States
diyAudio Member
 
cbj591's Avatar
 
Join Date: May 2010
Correct, the phase can and will be different at certian points in the program material.

I was speaking in basic terms of the wiring without getting to in depth. I just didn't want him to keep turning it up is the bass output was low and fry the voice coils.

Good catch...

Brian
  Reply With Quote
Old 28th July 2010, 02:43 AM   #17
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 96
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by David_Web View Post
Bass is not always in phase so you run the possibility if wasting energy and melt it (if they are out of phase at that point).
Yeah, that's a good point. If the signals to the two voicecoils mainly cancel out then there will be little output but plenty of heat in the coils. Normal voicecoil cooling does depend to some extent (not sure how much - does anyone know about such things?) on it moving. A static voicecoil seems to me to be more likely to fry than one in motion at the same power level.
__________________
It doesn't have to take the form of a conspiracy, rather a consensus... James H Kunstler

Last edited by abraxalito; 28th July 2010 at 02:46 AM.
  Reply With Quote
Old 28th July 2010, 03:39 PM   #18
epa is offline epa  Netherlands
diyAudio Member
 
Join Date: Apr 2010
Location: amsterdam
so what is the purpose of a dual vc speaker?
4 instance in my car i have an 18" dvc speaker
one vc connected 2 the left output of my amp the other one 2 the right channel.
this is working for 5 years.
the only thing i smell is the amp after while of d&b
my gues is that it may be sligtly out of phase some times ,but never a complet cancelation

Last edited by epa; 28th July 2010 at 03:43 PM. Reason: added info
  Reply With Quote
Old 28th July 2010, 03:45 PM   #19
Boscoe is offline Boscoe  United Kingdom
diyAudio Member
 
Join Date: Feb 2010
Location: England
I want to use it as a sub and it seems to be alright to do what I want.

Thanks
  Reply With Quote
Old 28th July 2010, 05:15 PM   #20
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Quote:
Originally Posted by Boscoe View Post
I want to use it as a sub and it seems to be alright to do what I want.

Thanks
I hate to pop in after much discussion, but not clear where you are coming from, where you want to go, and what efforts and education on your part you welcome performing.

While standing on one leg, let me offer a synopsis. Having a single woofer is a great idea (better one good woofer than two poor ones, eh) and owning a dual voice coil gives you options most people lack. But the cross-over frequency has to be below a frequency that upsets your stereo image (I'd say as high as 150 Hz and have more than 43 yrs of experience with mixed bass, but nobody would agree with me).

Today, and in the context of this DIY board, most would urge you to do an electronic mixer and crossover and not fuss with lousy low-level crossovers. Besides, at low frequencies, there's no way to make a sharp crossover using coils and capacitors and you must keep those low frequencies out of your mid-range. Again expecting nobody to agree with me, a third-hand amp from 1985 is a perfect match in quality to the best speakers today.

On the other hand, if all your boxes are close to one another, easy enough to create a low-level crossover over 200 Hz and just treat the woofer as if it were two units with each fed by each side.
__________________
Dennesen ESL tweets, Dayton-Wright ESL (110-3200Hz), mixed-bass Klipschorn + giant OB using 1960's Stephens woofer; Behringer DSP
HiFi aspirations since 1956

Last edited by bentoronto; 28th July 2010 at 05:18 PM.
  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
designing simple low pass subwoofer filter asbn369 Subwoofers 8 2nd August 2010 12:55 PM
Low Pass filter for sub? cathode_ray Subwoofers 9 25th April 2007 05:04 PM
low pass filter AudioAddicted Car Audio 17 2nd November 2006 06:44 AM
NO low pass filter? jmar Digital Source 7 19th January 2006 12:53 PM
low pass filter crazyant Car Audio 3 15th September 2005 06:15 PM


New To Site? Need Help?

All times are GMT. The time now is 02:14 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