Adjustable Passive Crossover? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 September 2011, 03:38 PM   #1
diyAudio Member
 
nonsuchpro's Avatar
 
Join Date: Sep 2011
Location: Bowie, MD
Question Adjustable Passive Crossover?

Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!
  Reply With Quote
Old 11th September 2011, 03:44 PM   #2
diyAudio Member
 
rvrazvan's Avatar
 
Join Date: Jul 2010
you can build something similar i guess. but what's the point? go active(digital)
  Reply With Quote
Old 11th September 2011, 04:03 PM   #3
Helmuth is offline Helmuth  Netherlands
diyAudio Member
 
Helmuth's Avatar
 
Join Date: Oct 2008
Location: Winterswijk
Quote:
Originally Posted by nonsuchpro View Post
Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!
With bipolar capacitors and switches it would not be to expensive, only coils will be and high cost.

serie coils you can ad the value parallel them L=1/(1/L+1/L)
capacitors parallel you can ad the value series C=1/(1/C+1/C)

Why make it this difficult, just calculate the XO. And buy a big coil then unwind the to big coil to the right value. You need to measure the value with a LCR meter. Or buy 3 coils one almost the right value and two small ones who you can place in series and paralel lets say 3mH and two 1mH. Then you can make 0,42mH 0,5mH 0,75mH 1mH 1,75mH 2mH 3mH 3.5mH 4mH 5mH .

buy not the calculated capacitor but parallel small ones to the right capacitance so you can remove rome and have smaller value or bigger when adding more capacitors.
__________________
( (( KUGELWELLE )) )
recent projects :OB-mk1 /fatboy / monitor-xl / Horn-AM / dappolito / td124-mk1-rb301 / Hybrid-pse / Vfet

Last edited by Helmuth; 11th September 2011 at 04:13 PM.
  Reply With Quote
Old 11th September 2011, 04:17 PM   #4
diyAudio Member
 
nonsuchpro's Avatar
 
Join Date: Sep 2011
Location: Bowie, MD
Quote:
Originally Posted by rvrazvan View Post
you can build something similar i guess. but what's the point? go active(digital)
Well honestly, i want something I can install in a speaker like an L-Pad. I just haven't come across such a beast
  Reply With Quote
Old 11th September 2011, 04:18 PM   #5
diyAudio Member
 
nonsuchpro's Avatar
 
Join Date: Sep 2011
Location: Bowie, MD
Quote:
Originally Posted by Helmuth View Post
With bipolar capacitors and switches it would not be to expensive, only coils will be and high cost.

serie coils you can ad the value parallel them L=1/(1/L+1/L)
capacitors parallel you can ad the value series C=1/(1/C+1/C)

Why make it this difficult, just calculate the XO. And buy a big coil then unwind the to big coil to the right value. You need to measure the value with a LCR meter. Or buy 3 coils one almost the right value and two small ones who you can place in series and paralel lets say 3mH and two 1mH. Then you can make 0,42mH 0,5mH 0,75mH 1mH 1,75mH 2mH 3mH 3.5mH 4mH 5mH .

buy not the calculated capacitor but parallel small ones to the right capacitance so you can remove rome and have smaller value or bigger when adding more capacitors.
Easier said than done, I'm not an "internals" expert. lol
But i'm learning

Thanks for this!
  Reply With Quote
Old 12th September 2011, 12:46 AM   #6
MCPete is offline MCPete  United States
diyAudio Member
 
Join Date: Nov 2005
A passive filter's cut-off frequency is dependent on load impedance. A two way speaker system including two woofers and two tweeters would give you three different crossover frequencies switchable at the speaker.

For the woofers, one woofer can be connected into the network and the other one left out, or the woofers can be connected in series or parallel. If the nominal impedance of each of the woofers is 8 Ohm, this gives you 8, 16, or 4 Ohms load impedance.

The switching of the pair of tweeters would be the same as that of the woofers.

When connecting in parallel, the voltage sensitivity would increase by 6 dB relative to the two other load settings. Compensating for that would make the set-up somewhat complicated, but if you can live with a 6 dB jump in that one case, the manual switching circuit isn't going to be too difficult to implement.

Unlike a L-pad, the above only allows for large steps in the crossover frequency, not at all close to an infinitely variable change. If you wanted something infinitely variable and passive, then that is probably relatively much more complicated and expensive.

Another possibility would be a ganged L-pads for each of a single woofer and single tweeter in a two-way system, except that you modify the variation of series and parallel resistance of each L-pad to increase or decrease load impedance.

My apologies if either of the two above proposals are the same as the vidsonix method (I didn't take a look at that yet).

Regards,
Pete

Last edited by MCPete; 12th September 2011 at 12:55 AM. Reason: add. idea
  Reply With Quote
Old 12th September 2011, 09:55 AM   #7
Francec is offline Francec  Australia
Banned
 
Join Date: Jul 2006
Location: Port Melbourne, Australia
Quote:
you can build something similar i guess. but what's the point? go active(digital)
Yep, easier and better.
  Reply With Quote
Old 14th September 2011, 11:58 PM   #8
MCPete is offline MCPete  United States
diyAudio Member
 
Join Date: Nov 2005
Quote:
Originally Posted by nonsuchpro View Post
Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!
Did you want to have an adjustable crossover frequency adjustment as a permanent feature of a finished speaker system, or a temporary rig for settling on the best crossover frequency for a speaker?

I like the idea, so I'm just curious as to what you hoped to accomplish with it.

Regards,
Pete
  Reply With Quote
Old 15th September 2011, 12:42 AM   #9
diyAudio Member
 
Join Date: Apr 2010
Location: Oregon
I wonder if a variac would make a good variable inductor for this purpose. Anybody know what inductance range to expect?
  Reply With Quote
Old 15th September 2011, 07:55 AM   #10
diyAudio Member
 
nonsuchpro's Avatar
 
Join Date: Sep 2011
Location: Bowie, MD
Quote:
Originally Posted by MCPete View Post
Did you want to have an adjustable crossover frequency adjustment as a permanent feature of a finished speaker system, or a temporary rig for settling on the best crossover frequency for a speaker?

I like the idea, so I'm just curious as to what you hoped to accomplish with it.

Regards,
Pete
Yes, as a permanent feature of the speaker. I think it would have good advantages like driver swap outs and possible room adjustments, wall distance, etc.... IDK, something different... tired of the same ol
  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
adjustable inductor in SP1/2E crossover spendorspain Multi-Way 11 26th January 2008 04:20 PM
crossover software - adjustable while listening to a song jaygeorge1979 Multi-Way 32 5th January 2006 06:18 AM
adjustable crossover rv1890 Multi-Way 2 11th January 2005 10:03 PM
adjustable resistor or potentiometer choise to use in a crossover maya1 Multi-Way 1 2nd May 2004 02:41 PM
Adjustable Infinite Slope Crossover Rarkov Solid State 1 22nd September 2002 07:02 PM


New To Site? Need Help?

All times are GMT. The time now is 12:07 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