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Speaker cone feels "loose". Is it damaged?

Mitkraft

Mitkraft

Super Member
I have a pair of Infinity CS3006 that I planned on refoaming since the surrounds are nearly gone. I got them in this condition so I don't know the history. One cone feels normal but the other is "loose" and "floppy". If I manually move the normal feeling cone you can fell the pull of the magnet and that the voice coil is still centered. The other cone feels almost as if there isn't a magnet since it moves more freely and you can feel it rubbing on whatever side you move it towards.

Assuming my description makes sense and tells you anything, what does this mean? Is the speaker toast or will a refoam job bring it back into place? Is there another failure I need to check for? I was pretty sure when I got these I tested the drivers by laying the speaker on its back and playing at very low volume just enough to hear each speaker working.

Just realized one bit of detail wasn't clearly spelled out: The foam on both speakers is toast and almost completely crumbled.

Any help is appreciated. Thanks!
 
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Mitkraft said:
I have a pair of Infinity CS3006 that I planned on refoaming since the surrounds are nearly gone. I got them in this condition so I don't know the history. One cone feels normal but the other is "loose" and "floppy". If I manually move the normal feeling cone you can fell the pull of the magnet and that the voice coil is still centered. The other cone feels almost as if there isn't a magnet since it moves more freely and you can feel it rubbing on whatever side you move it towards.

Assuming my description makes sense and tells you anything, what does this mean? Is the speaker toast or will a refoam job bring it back into place? Is there another failure I need to check for? I was pretty sure when I got these I tested the drivers by laying the speaker on its back and playing at very low volume just enough to hear each speaker working.

Any help is appreciated. Thanks!
Click to expand...

Well I would put a meter on them and do a ohm test.

Best-

Boozehound
 
Sounds like toasted foam on the floppy one. Also check the spider (glue et.al.).
Unless you have the speakers playing when you are moving the cone; or the voice coil is wound with steel wire, the coil passing the magnet provides no resistance.
The spider and surround provide the resistance and keep the voice coil centered.
 
Yes check the spider. If that's OK it may just be the foam is more shot on one than the other. But if it was played hard without foam, the flopping could have loosened or disconnected the spider.

If it looks OK and plays ok at low volume on its back then refoam and see how it is.
 
SaturationPt said:
This is an example of a disconnected spider.
Click to expand...

Ahh, the spider, that makes sense. Is the "disconnected" part the cracked looking areas near the voice coil? Is a disconnected spider repairable? I haven't come across any info (not that I've looked) about disconnected spiders and what to do about it.
 
In the case of the speaker in the photo, a "cone kit" from JBL includes the spider, voice coil assembly, cone, surround, dust cap so it isn't a concern, especially with a bolted magnet assembly.

I don't know how your speaker is constructed, but I believe that Simply Speakers does stock/sell spiders as well as foam and cones for many speakers. If you're replacing the foam, this would be the time to replace the spider if it is not in good condition.

As far as repairing? I don't think it's worth repairing.
 
The spider might just need to be re glued to the frame or cone. When I was re foaming a woofer on a 35 year old driver the spider came unglued from the frame once. it was just old glue which had deteriorated, the spider it's self was fine.
 
Defenitly has a broken spider. The voice coil is rubing pretty good to when I move it bu hand, is that just because the spider is broken? It reads 3.6 ohms btw.

Can the spider be repaired? Replaced? Advice?
 

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That might be repairable, looks like it sheared at the glue line. The glue edge became the flex-point of the spider and probably simply fatigued there. I think I'd try gluing them together, then possibly wet a small-thin ring beyond the glue line with an epoxy or other flexible material to spread some of the strain out away from a hard glue-line (I would use West Systems epoxy, I'm a boater so I keep it around. Other epoxy like a fiberglass resin material should also work). Be sure it's centered well.

OTOH, if you're re-foaming anyway, this would be the time to replace the spider if available (which is likely a better solution).
 
I'm looking around and I haven't yet found any replacement spiders that specifically say they are for this speaker. That leaves me with two questions:

1. Like foams, is there a way to buy a generic replacement spider based just off size?
2. If the spider is completely detached from the voice coil and cone, can I lift out the voice coil to visually check for damage? I'm concerned about its health as well.
 
I can't answer your question about a replacement spider, but I can say the glue from simply speaker is very forgiving and you can reposition things many times if needed. Personally I would reglue what you have and try it. The question is glue the surround first or the spider? From my limited experience from the one that came apart on me I would( If had to do it again) I would do the surround first and get it lined up good this way you have support and the cone won't be flopping around while you reglue the spider. if the surround is lined up properly I am willing to bet the spider will fall right in to place and inline to where it broke making regluing it and final tweaks if needed relatively easy.
 
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This would be a good time to cut out the dust cap and shim the voice coil when you're refoaming. I've done plenty of refoams without shimming and never had a problem with the VC rubbing, but that's because the spider is keeping things centered. If you shim and refoam, the voice coil will then be both centered and stabilized by the cone/surround.
 
toxcrusadr said:
This would be a good time to cut out the dust cap and shim the voice coil when you're refoaming. I've done plenty of refoams without shimming and never had a problem with the VC rubbing, but that's because the spider is keeping things centered. If you shim and refoam, the voice coil will then be both centered and stabilized by the cone/surround.
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That's exactly what I was thinking as well. I hadn't planned on removing the dust cap and shimming the voice coil but with the spider and cone being detached I'm betting that is the best way to do it. I'm going to plan on taking NH-MAN's advice and gluing the surround first then attempting the repair on the spider.

That leaves me with two unanswered questions:

1. With the spider and surround detached is it safe to remove the voice coil for inspection? Obviously I'd have to be careful of the two leads, but should the rest of the coil remain intact on removal? I'm led to believe that if it should remain intact unless its "blown".

2. What adhesive (preferably that I can get at the hardware store or wallmart) is best to use on the spider? I'm guessing the foam adhesive isn't preferable.

Thanks for the help and advice guys!!
 
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Mitkraft said:
That's exactly what I was thinking as well. I hadn't planned on removing the dust cap and shimming the voice coil but with the spider and cone being detached I'm betting that is the best way to do it. I'm going to plan on taking NH-MAN's advice and gluing the surround first then attempting the repair on the spider.

That leaves me with two unanswered questions:

1. With the spider and surround detached is it safe to remove the voice coil for inspection? Obviously I'd have to be careful of the two leads, but should the rest of the coil remain intact on removal? I'm led to believe that if it should remain intact unless its "blown".

2. What adhesive (preferably that I can get at the hardware store or wallmart) is best to use on the surround? I'm guessing the foam adhesive isn't preferable.

Thanks for the help and advice guys!!
Click to expand...
If the leads are long enough there should not be an issue with taking a peak. Obviously you want to be careful not to harm the voice coil by denting it ect.(they are pretty tough) I would order a tube from simply speakers as it is great to work with and you will have plenty left over to do more down the road. I did 4 6.5 surrounds and a 15" surround re glue to the frame (it was old and came loose) and still have some left.
Oh might want to make a mark on the cone and the spider with a sharpie so you can line them back up during reassembly so all the low and high spots where it broke will align back up
 
NH-MAN said:
If the leads are long enough there should not be an issue with taking a peak. Obviously you want to be careful not to harm the voice coil by denting it ect.(they are pretty tough) I would order a tube from simply speakers as it is great to work with and you will have plenty left over to do more down the road. I did 4 6.5 surrounds and a 15" surround re glue to the frame (it was old and came loose) and still have some left.
Click to expand...

OOPS! I misspoke. My question was meant to be "What adhesive is best to use on the spider" (original question now correct). I have adhesive that came with the surrounds, but I'm guessing surround adhesive is not best suited for the spider repair. I've read that you want something strong and flexible like a rubber cement or 2 part epoxy.
 
epoxy is brittle, I used the same glue as the surround but someone else might have a different thought on it. I am not aware of there being a differnt kind of glue just for the spider which leads me to believe one would use the same glue as the surround. It looks the same
 
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