Blown woofer- Coil replace or Passive Radiator - 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 15th April 2003, 02:58 AM   #1
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
Default Blown woofer- Coil replace or Passive Radiator

I've got a blown speaker here that I'd eather like to fix or convert into a passive radiator. How can I replace the voice coil? Or is it probably better to just get a new speaker ($110)? I am going to contact the company before I make it a PR.

If I convert it into a passive radiator, I will want to remove the magnet, right? Would that change the free air resonance at all? Anyone had any experience with this?
  Reply With Quote
Old 15th April 2003, 03:32 AM   #2
karma is offline karma  Canada
diyAudio Member
 
karma's Avatar
 
Join Date: Feb 2003
Location: hamilton,ontario
Default dang

i have fixed a blown speaker in the past with good results.
i took a butter nife and removed the surrounds from the frame of the speaker and from the side got the spider off around the edges. takes a lot of work but i got the cone and cole out to rewire it.than just used rubber cement to put it back together.what have you got to loose if you mess it up just buy new
  Reply With Quote
Old 15th April 2003, 05:53 AM   #3
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
First of all, I AM A POOR MAN- I AM ON DIYAUDIO!!!

I've got a passive radiator to lose. Also, I don't know how to rewire the voice coil correctly, epseciallly for resistance and power handling. If possible I'd like to increase power handling and decrease resistance (doesn't everybody) but am afraid this will drasticly affect Thielle small parameters.

I am willing to spend time (not much money though) to fix this. I'd like the best fix possible. How to remove the voice coil from the spider? The coil seems to be sealed to the spider, which is sealed to the motor structure, connected to the magnet.

I don't want to lose the passive radiator abilities becase I'd like a PR and they cost over $70 for one with the movable volume this speaker has.

I don't have much money; I have a lot of time.
  Reply With Quote
Old 16th April 2003, 06:54 PM   #4
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
Come on guys.. nobody can give me any info on how to correctly rewire a coil, or remove the spider? Am I going to have to call the company for a replacement coil?

Superglue should work fine to stick it back together I'm guessing.
  Reply With Quote
Old 16th April 2003, 07:02 PM   #5
diyAudio Member
 
JOE DIRT®'s Avatar
 
Join Date: Apr 2003
Location: Brantford, ON
Carman...you can order a new voice coil no probs...there are companies that sell generic ones pretty cheap.......I`ve done it with pro woofers in a couple of hours....just dont use crazy glue...that crap dries out ....use a rubber butyl cement it can take the pounding

Cheers!!The DIRT®
  Reply With Quote
Old 16th April 2003, 11:03 PM   #6
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
Alright so superglue is probably a bad idea? More than drying out I suspect that it will break before bending, unlike butyl rubber cement.
My father said he doubted the voice coil was blown, and it's probably some wiring or the ring next to the coil, so...
I've taken off the dustcap to test the conduction of the voice coil, which is still intact. I then inspected the leads again, and there is a black hole on each positive lead (dual voice coils) next to the coil. Burnt right through the spider and fried an 8-10 guage lead. Nothing like 1000W overdriven at 15-20hz to destroy your 1200W max speakers. The problem is I can no longer see the part of the lead that connects to the coil. The leads were woven into the spider. I'll have to remove the entire cone/spider assembly in order to get in there. Should I get some ribbon cable like the leads and attemp to solder it?
As an alternative I could poke a small hole through the cone (spruce pulp) underneath the dustcap (very stiff plastic) and wire the leads directly to the leads underneath the dustcap. This might screw up the sound a lot, but I wouldn't have to remove the cone/spider. If removal of the cone can be avoided I think it would be best.
2 holes about 4mm in diameter in the spider shouldn't mess things up too bad, should it? I could attempt to patch the holes but want to leave it as original as possible.
Keep in mind that I'd like to use this as a passive radiator if repairs fail. A PR moving 2.5L costs over $50 as far as I can tell. 2 small holes underneath the dustcap, just large enough for wire to pass through, shouldn't affect the passive radiator abilities at all, right? The dustcap and cone are both VERY stiff.

What kind of glue/cement/tape takes a lot of heat without melting and doesn't affect the resistance/capacitance of a wire? I'm going to affix the new lead to the cone to avoid lead slap. Will superglue melt/conduct/capacitate? If I use a larger lead to avoid blowing it again will this affect any of the woofer parameters?

Adding mass to the speaker should lower the resonant frequency and efficiency, while raising the Vas?
  Reply With Quote
Old 16th April 2003, 11:16 PM   #7
diyAudio Member
 
JOE DIRT®'s Avatar
 
Join Date: Apr 2003
Location: Brantford, ON
you could use the same butyl rubber to block up the holes its a great sealant also....I have used plain silicone on tears and holes with great success with no sound compromise....if your worried about that much heat then a high heat silicone will work.....and silicone is not conductive....I have extensive experience with automotive applications where we had to protect relays and circuits with no problems.

also if I could add some advice...everytime I have ever repaired a speaker I have always ran 4-8 Ohm 10 watt resistor in series with the driver and let it run for awhile.....that way if something shorts out it does ruin your amp


Cheers!!The DIRT®
  Reply With Quote
Old 17th April 2003, 02:58 AM   #8
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
I have some copper wire here that is already a good mesh and size, and some nickel wire that I'd need to double up and is not as flexible. Why are the leads generally made of nickel (or is it some other metal?) Is there some property that makes it ideal or would the copper be just as good?

I've shorted the amp at the speaker terminals with no problem- on accident of course. Yes, heat is a major problem here with 700watts rms running through it. After a car drive lasting more than 30 minutes I could go back and feel the magnet radiating heat, and got pretty close to burning my hand. Silicone should do the trick
  Reply With Quote
Old 17th April 2003, 03:08 AM   #9
diyAudio Member
 
JOE DIRT®'s Avatar
 
Join Date: Apr 2003
Location: Brantford, ON
the copper wire should be ok.....but I ask why its getting so hot>????....maybe your over driving it......my pro sub has a vent in the back as big as a ****** bottom and It stays cool....if your persistent on using that driver maybe a different box design to yeild the spl you are looking for>??

Cheers!! the DIRT®
  Reply With Quote
Old 17th April 2003, 03:40 AM   #10
CarMan is offline CarMan  United States
diyAudio Member
 
Join Date: Mar 2003
Location: Reno
From what I've found copper is only bad for high frequencies, in which case it's better to use silver. Temps are possibly high due to overdriving.
Linear peak to peak excursion is 32mm but I've measured the cone traveling up to about 50mm with a ruler, by eye. This sub was built for spl and has a somewhat low efficiency (88db) and stiff surround. I bought it for the mix of quality and spl, since it produces flat response down to 20hz in an anechoic chamber in an 88L ported box, at 111db, for $110. I actually didn't expect it to sound as good as it did. After blowing one I've had the chance to listen to the other in an infinite baffle (in the car). Good definition and a flat response to 15hz in car, at which point my amplifier has a subsonic crossover.
  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
Replace blown tweeters Dirge Multi-Way 5 27th October 2006 02:29 AM
Blown speaker (coil?) anything I can do? aletheian Multi-Way 7 4th December 2005 11:54 PM
passive radiator ??? Ahmad_tbp Multi-Way 20 29th March 2005 08:44 AM
Passive Radiator For ESS qdoc Multi-Way 0 8th July 2004 06:06 AM
blown voice coil krimet420 Multi-Way 3 10th December 2003 03:30 PM


New To Site? Need Help?

All times are GMT. The time now is 06:56 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