Crossover Replication Difficult? - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

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 9th August 2012, 06:33 PM   #1
diyAudio Member
 
Join Date: Dec 2005
Question Crossover Replication Difficult?

Is it difficult to replicate a crossover made by a manufacturer? I have one of two that is failing. They are not cheap. Hopefully the problem is just a microscopic sized solder joint crack that I can redo. It will supply to the midrange but not the tweeter. However, after some 20-40 minutes of play, the tweeter will start to come in occasionally (Iím thinking the xover is heating up and that temporarily fixes it). The tweeter is fine because I tested it using the other xover. Can the items be measured electrically plus using the text on some of the components to replicate a new one?

The crossover that is wonky is one of the two for the Polk SR6500 driver set (which has been discontinued due to cost).

Thanks.
  Reply With Quote
Old 9th August 2012, 07:00 PM   #2
Einric is offline Einric  United States
diyAudio Member
 
Einric's Avatar
 
Join Date: Feb 2011
Location: Bozeman, MT
You should be able to find the values of the crossover components by looking closely at them.
I recently rebuilt some Polk Monitor crossovers from '92 and they worked great.
Most likely the problem you are having is either a solder joint or a capacitor, inductor problems don't just come and go.
  Reply With Quote
Old 9th August 2012, 07:03 PM   #3
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
I would run jumper wires to determine the location of the problem and resolder if that's the problem or renew a part if it has failed.
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 9th August 2012, 08:22 PM   #4
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
I'd agree on solder joints.


WHen the tweeter is not working, look for where the signal is lost. One thing to do is whack the side of the thing, if the tweeter pops on or tries to come on, that mechanical shock of whacking it exposed a loose connection. And just tap on each part on the thing, looking for one that responds with tweeter sound.

Crossovers usually have a lot of parts either glued down or strapped in place, but not all. In any case, any part of size that can vibrate can also break off its wires. SOmetimes you see a cap with a wire lead going into the hole in the cicuit board, and the other side has a nice smooth intact solder joint around the bend over wire lead, but inside the hole, that lead is snapped in two. SOmetimes it touches and sometimes it doesn;t.. SO moving/pushing/tugging on each part can expose that.

Similarly, grasp the circuit board and flex it. That also can reveal broken or cracked connections.

certainly we want to look VERY closely at all the solder joints for small cracks around the lead ends.
  Reply With Quote
Old 9th August 2012, 09:51 PM   #5
diyAudio Member
 
Join Date: Dec 2005
Location: Kuala Lumpur
There is likely to be a series dropper resistor, which could be cooked
  Reply With Quote
Old 10th August 2012, 09:52 AM   #6
diyAudio Member
 
Join Date: Dec 2005
Quote:
Originally Posted by Enzo View Post
I'd agree on solder joints.

WHen the tweeter is not working, look for where the signal is lost. One thing to do is whack the side of the thing, if the tweeter pops on or tries to come on, that mechanical shock of whacking it exposed a loose connection. And just tap on each part on the thing, looking for one that responds with tweeter sound.

Crossovers usually have a lot of parts either glued down or strapped in place, but not all. In any case, any part of size that can vibrate can also break off its wires. SOmetimes you see a cap with a wire lead going into the hole in the cicuit board, and the other side has a nice smooth intact solder joint around the bend over wire lead, but inside the hole, that lead is snapped in two. SOmetimes it touches and sometimes it doesn;t.. SO moving/pushing/tugging on each part can expose that.

Similarly, grasp the circuit board and flex it. That also can reveal broken or cracked connections.

certainly we want to look VERY closely at all the solder joints for small cracks around the lead ends.
Thank you for the agreement on solder joints! (I hope it is just that)

A very small and visually undetectable solder joint crack unless using a loupe is my hope (I have loupes for photography purposes). I found a crack in my Jeep's 'internal lighting amount slider switch' and it was only the loupe that showed the microscopic crack that caused the sometimes on/off electrical connection. I resoldered it and saved myself like $400 from the dealer!

The board inside each xover is not flexible, heh. Polk installed them in heavy steel heatsinks so I would have to remove the board. Overkill for the heatsinks if you ask me. Each mid/tweet combo driven by each xover can handle 125rms and I have a 150rms/ch amp. But, my EARS cannot handle that kind of rms, heh.

I most definitely appreciate all the advice and, as I mentioned above, I have seen solder joints crack in a very, VERY tiny way which makes them wonky. I'll carefully take apart the wonky xover and inspect it.

Thanks ALL! Truly appreciate it!

Or, as others have said, it can be rebuilt! Nice!
  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
Summer Project - Replication of MBL loudspeaker 101mkII Magnasanti Planars & Exotics 77 21st November 2012 08:31 AM
Difficult Question jpetek Multi-Way 8 20th August 2008 10:50 AM
battery charger = difficult taloyd Parts 10 1st July 2005 06:33 PM
Are TL's difficult to build? ERICSPEEd Subwoofers 23 14th December 2004 03:28 PM
What is a difficult load? Bricolo Solid State 9 23rd August 2003 03:37 AM


New To Site? Need Help?

All times are GMT. The time now is 04:43 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