Assistance required in rebuild of a focal 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 30th March 2009, 10:07 AM   #1
diyAudio Member
 
Join Date: Mar 2008
Default Assistance required in rebuild of a focal crossover

Hey everyone!

I have an old focal speaker that I would like to rebuild the crossover with some higher quality components.

Attached are two pictures front and back

C1 - 3.3J 250V
C2 - 6.8J 250V
C3 - 18uF 63V
C4 - 33uF 63V

R1 - 7R1/7W (7.1 ohms / 7 Watts)
R2 - 10R/10W (10 ohms / 10 Watts)
R3 - 1R8/10W (1.8 Ohms / 10 Watts)

L1 - Unknown, need to test with multimeter
L2 - Unknown, need to test with multimeter
L3 - Unknown, need to test with multimeter
L4 - Unknown, need to test with multimeter
L5 - Unknown, need to test with multimeter

Click the image to open in full size.

Click the image to open in full size.
  Reply With Quote
Old 30th March 2009, 10:08 AM   #2
diyAudio Member
 
Join Date: Mar 2008
Any ideas what C1 and C2 capacitors are in uF?
  Reply With Quote
Old 30th March 2009, 10:09 AM   #3
diyAudio Member
 
Join Date: Mar 2008
Could someone help reconstruct the layout?
  Reply With Quote
Old 30th March 2009, 10:39 AM   #4
diyAudio Member
 
Join Date: Mar 2008
Worked out C1 and C2

3.3uF and 6.8uF
  Reply With Quote
Old 30th March 2009, 10:42 AM   #5
diyAudio Member
 
jerome69's Avatar
 
Join Date: Feb 2008
Location: Lyon
Hello,

C1 and C2 are in uF. You can change C3 and C4 by film capacitors.
Don't change the inductors.


  Reply With Quote
Old 30th March 2009, 10:44 AM   #6
diyAudio Member
 
Join Date: Mar 2008
Looks like the resisters are ceramic, can they be changed to MOX?
  Reply With Quote
Old 30th March 2009, 10:47 AM   #7
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by jerome69
Hello,

C1 and C2 are in uF. You can change C3 and C4 by film capacitors.
Don't change the inductors.



Hi,

So I could not use Mundorf Mcap Supremes for C3 and C4?

Thanks.
  Reply With Quote
Old 30th March 2009, 10:49 AM   #8
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by soundengine355
Looks like the resisters are ceramic, can they be changed to MOX?
How would:

R1 7.1ohms/7W TO 1.5 + 5.6 ohm 20W MRESIST Supreme Resistor
R2 10ohm/10W TO 10 ohm 20W MRESIST Supreme Resistor
R3 1.8ohm/10W TO 1.8 ohm 20W MRESIST Supreme Resistor
  Reply With Quote
Old 30th March 2009, 11:02 AM   #9
pjpoes is offline pjpoes  United States
diyAudio Member
 
Join Date: Jan 2005
Location: New York
Send a message via AIM to pjpoes
adding resistors in parallel reduces resistance. Adding in series adds it, but also increases inductance (still typically quite small) and puts undo load on the higher value resistor. I wouldn't recommend this, just use the right value.

The electrolytic caps can be changed to film, but they will be huge, and may have a negligible effect on sound. They are probably in the woofer lowpass filter, and thus in parallel.

I know you won't probably do this, but I had a whole writeup on my rebuild of some focal speakers. An Electra Center and L-R speakers, and my rebuild found the greatest improvement by redesigning the crossover. Numerous measurements were taken of the individual drivers as well as the entire system both in a room and free space, as well as a lot of modeling. The final result was the largest single improvement I could have made. While changing the parts with better ones may make a difference, it's in the last .1% type change, where as changing the crossover was much more substantial. I fear you will invest a lot of money into upgrading parts only to find the improvement minimal if audible at all.
  Reply With Quote
Old 30th March 2009, 11:08 AM   #10
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by pjpoes
adding resistors in parallel reduces resistance. Adding in series adds it, but also increases inductance (still typically quite small) and puts undo load on the higher value resistor. I wouldn't recommend this, just use the right value.

The electrolytic caps can be changed to film, but they will be huge, and may have a negligible effect on sound. They are probably in the woofer lowpass filter, and thus in parallel.

I know you won't probably do this, but I had a whole writeup on my rebuild of some focal speakers. An Electra Center and L-R speakers, and my rebuild found the greatest improvement by redesigning the crossover. Numerous measurements were taken of the individual drivers as well as the entire system both in a room and free space, as well as a lot of modeling. The final result was the largest single improvement I could have made. While changing the parts with better ones may make a difference, it's in the last .1% type change, where as changing the crossover was much more substantial. I fear you will invest a lot of money into upgrading parts only to find the improvement minimal if audible at all.
Hi,

This is good to know, what Electra models do you have?

Thanks
  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
Crossover help required zebra100 Multi-Way 11 15th December 2008 02:52 PM
Hi everyone. Assistance required for DIY Audio beginner! the_chase1 Introductions 4 24th November 2008 10:55 PM
need crossover help with focal 7w4411 and td90tdx mdelrossi Multi-Way 5 30th July 2008 03:26 AM
Orion crossover assistance needed SteveA Multi-Way 8 16th January 2004 06:48 PM


New To Site? Need Help?

All times are GMT. The time now is 02:04 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