Variable phase subwoofer - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 20th October 2002, 02:38 PM   #1
palesha is offline palesha  India
diyAudio Member
 
Join Date: Nov 2001
Location: Pune India
Default Variable phase subwoofer

I have seen new subwoofers with variable phase. Anybody have designed or used this type of circuit? I will like to know more about the circuit so that i can add the same to my subwoofer.
Mahendra Palesha
  Reply With Quote
Old 21st October 2002, 12:09 PM   #2
f4ier is offline f4ier  Australia
diyAudio Member
 
f4ier's Avatar
 
Join Date: Sep 2001
Location: Sydney
The circuit is called an All-Pass Filter; linkwitzlab.com has a bit of information on a first order APN -- http://www.linkwitzlab.com/filters.htm

hth

Isaac
Attached Images
File Type: png apn.png (12.7 KB, 437 views)
__________________
Crossover/Subwoofer Simulator
  Reply With Quote
Old 22nd October 2002, 04:24 AM   #3
diyAudio Member
 
dhengkoel's Avatar
 
Join Date: Nov 2001
Location: CIA
Try this link too: http://www.rane.com/library.html

Regards:
ragil.hastomo
__________________
:: The last but not least ::
  Reply With Quote
Old 22nd October 2002, 06:02 AM   #4
argo is offline argo  Estonia
diyAudio Member
 
Join Date: Feb 2001
Location: Estonia
Both circuits (shown on Linkvitz page and Rane manuals) will work
BUT you need Exponential curve tracking potentiometer (single for 180 deg and dual ganged pot for 360 deg variations) to make these circuits usable.

Argo
  Reply With Quote
Old 22nd October 2002, 05:57 PM   #5
palesha is offline palesha  India
diyAudio Member
 
Join Date: Nov 2001
Location: Pune India
argo,
Can u give details of the circuits u have mentioned at the two sites? More information about the Exponential curve tracking potentiometer is required.
MP
  Reply With Quote
Old 23rd October 2002, 09:16 AM   #6
argo is offline argo  Estonia
diyAudio Member
 
Join Date: Feb 2001
Location: Estonia
Quote:
Originally posted by palesha
argo,
Can u give details of the circuits u have mentioned at the two sites? More information about the Exponential curve tracking potentiometer is required.
MP
Isaac has already shown a typical allpass filter - also called delay filter i.e. a filter that passes all frequencies and only delays the signal to certain degree and consequently alters the phase. The gain of the filter is 1. The value of the Rf is kept equal and unchanged while by changing the value of resistor R you can delay the signal - here is where you need potentiometer. But changing the resistor R value doesnít alter phase by linear relationship but logarithmically. For an example: turning your 10k linear potentiometer from 0 position to 50% of its turn will not change phase from 0 deg to - 90 deg as you would have wanted, 75% turn wonít change the phase to 135 deg, and so on. Thatís why you may want to use exponential (inverse logarithmic) potentiometer in order to maintain linear scale when turning your potentiometerís knob.
Now if you use one of such filter bloc, you can change the phase from 0 to - 180 deg, if you use two of those identical blocs (hence the dual pot need) in series it will be possible to change the phase of the signal from 0 to -360 deg.
Look also at http://www.linkwitzlab.com/filters.htm 4 - Delay correction
Click the image to open in full size.

and http://www.rane.com/pdf/ac22sch.pdf find detail 2: Rane's typical delay circuit.

Argo
  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
variable phase 0-180 deg. Marcelinho Subwoofers 3 31st December 2006 02:14 AM
Circuit for variable phase 0-180 control for active L/R xover georgehifi Solid State 4 20th September 2006 10:55 AM
Subwoofer variable phase control AudioFreak Solid State 23 18th July 2004 04:54 PM
Simple variable subwoofer Crossover.. deepanger Solid State 5 25th February 2003 02:47 AM
Variable phase circuit for sub ergo Subwoofers 1 29th August 2001 01:06 PM


New To Site? Need Help?

All times are GMT. The time now is 04:58 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