Scored lines on speaker voice coil former

N

N_Cook

Guest
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one end
to the other , so if made in use would require the diaphragm (spider?) being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one end
to the other , so if made in use would require the diaphragm (spider?) being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.
Click to expand...
Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)
 
Ron <ron@lunevalleyaudio.com> wrote in message
news:vLudnWM2Pu2treLUnZ2dnUVZ8vqdnZ2d@bt.com...
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the
phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each
pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one
end
to the other , so if made in use would require the diaphragm (spider?)
being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.

Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)
Click to expand...
the lines are on the smooth internal surface that glides over the central
section of the magnet, not the coil surface.

I doubt the lines are anything to do with the failure, that is well outside
the coil area. Probably due to stress on epoxy curing on a supposed stress
relieving bend of the coil runout wire inside a fillet ring of epoxy where
the cone meets the phenolic cylinder and before the join with the pigtail,
so repairable.

Will try a pic of the lines


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
Ron <ron@lunevalleyaudio.com> wrote in message
news:vLudnWM2Pu2treLUnZ2dnUVZ8vqdnZ2d@bt.com...
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the
phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each
pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one
end
to the other , so if made in use would require the diaphragm (spider?)
being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.

Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)
Click to expand...
There is no overheating , scoring or any damage to the coil or elesewhere
just these lines.
http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg
Could someone confirm that the woven and corrugated yellow part I've
labelled purple "S" is called the spider. The cone is to the other side of
it.
"L" is the lead out of the coil and "G" is some sort of optical guide laid
in the layup, on the manderel, of the phenolic for placing the lead-outs to
then meet up with the pigtails at the cone. Moire fringing is where the coil
is. A second sight guide and second of a pair score line is part in shadow
off to the upper right.

There is a third and fourth pair of lines diametrically opposite these 2
pairs

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:
Ron <ron@lunevalleyaudio.com> wrote in message
news:vLudnWM2Pu2treLUnZ2dnUVZ8vqdnZ2d@bt.com...
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the
phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each
pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one
end
to the other , so if made in use would require the diaphragm (spider?)
being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.
Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)

There is no overheating , scoring or any damage to the coil or elesewhere
just these lines.
http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg
Could someone confirm that the woven and corrugated yellow part I've
labelled purple "S" is called the spider. The cone is to the other side of
it.
Click to expand...
Yes the rear suspension is traditionally refered to as the spider
because in early speakers it was a (usually) three legged tufnol affair
a bit like the '3 legs of Man' mounted insided the v/c and screwed to
the pole piece of the magnet. The v/c was centered by loosening off the
screw and moving the spider around. Often a low frequency (100 hz) (120
in the USA) note was played through the speaker whilst the adjustment
took place

"L" is the lead out of the coil and "G" is some sort of optical guide laid
in the layup, on the manderel, of the phenolic for placing the lead-outs to
then meet up with the pigtails at the cone. Moire fringing is where the coil
is. A second sight guide and second of a pair score line is part in shadow
off to the upper right.
Click to expand...

I dont think that line G is any form of optical sight, just where the
layup of the laminations of the former are recessed to feed the lower
coil leadout up

There is a third and fourth pair of lines diametrically opposite these 2
pairs
Click to expand...
I think those are just marks made by withdrawing the coil former from
whatever chuck held it in the winding machine or curing oven - or both.

If there`s no rubbing or burning of the coil, you`ll probably find the
o/c is where the end of the coil passes throught the cone and is
soldered to the pigtail. This is sometimes repairable by scraping off
the glue and reheating the 'blob'. Not worth messing around tho,
replacement speakers like those are cheap.

Ron
 
N_Cook wrote:

Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one end
to the other , so if made in use would require the diaphragm (spider?) being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.
Click to expand...
How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham
 
Eeyore wrote:
N_Cook wrote:

Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one end
to the other , so if made in use would require the diaphragm (spider?) being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.

How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham

Graham,
Click to expand...

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?

jak
 
Ron <ron@lunevalleyaudio.com> wrote in message
news:9t2dnVSZuJsk3OLUnZ2dnUVZ8tDinZ2d@bt.com...
N_Cook wrote:
Ron <ron@lunevalleyaudio.com> wrote in message
news:vLudnWM2Pu2treLUnZ2dnUVZ8vqdnZ2d@bt.com...
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the
phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each
pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from
one
end
to the other , so if made in use would require the diaphragm (spider?)
being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.
Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which
seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)

There is no overheating , scoring or any damage to the coil or
elesewhere
just these lines.
http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg
Could someone confirm that the woven and corrugated yellow part I've
labelled purple "S" is called the spider. The cone is to the other side
of
it.

Yes the rear suspension is traditionally refered to as the spider
because in early speakers it was a (usually) three legged tufnol affair
a bit like the '3 legs of Man' mounted insided the v/c and screwed to
the pole piece of the magnet. The v/c was centered by loosening off the
screw and moving the spider around. Often a low frequency (100 hz) (120
in the USA) note was played through the speaker whilst the adjustment
took place

"L" is the lead out of the coil and "G" is some sort of optical guide
laid
in the layup, on the manderel, of the phenolic for placing the lead-outs
to
then meet up with the pigtails at the cone. Moire fringing is where the
coil
is. A second sight guide and second of a pair score line is part in
shadow
off to the upper right.


I dont think that line G is any form of optical sight, just where the
layup of the laminations of the former are recessed to feed the lower
coil leadout up


There is a third and fourth pair of lines diametrically opposite these 2
pairs

I think those are just marks made by withdrawing the coil former from
whatever chuck held it in the winding machine or curing oven - or both.

If there`s no rubbing or burning of the coil, you`ll probably find the
o/c is where the end of the coil passes throught the cone and is
soldered to the pigtail. This is sometimes repairable by scraping off
the glue and reheating the 'blob'. Not worth messing around tho,
replacement speakers like those are cheap.

Ron
Click to expand...

If it was scoring from expandable/contractable mandrel or a chuck of some
sort I'd expect it to be engineered and pairs of lines exactly 6mm or
something precise apart, these are about 6 to 8 mm apart and some lines have
a nearby accompanying line. They are white as in scoring not grooves set in
at moulding . Or more likely no marks as what is the point if the process
leaves such serious imperfections where you don't want them.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:
Ron <ron@lunevalleyaudio.com> wrote in message
news:9t2dnVSZuJsk3OLUnZ2dnUVZ8tDinZ2d@bt.com...
N_Cook wrote:
Ron <ron@lunevalleyaudio.com> wrote in message
news:vLudnWM2Pu2treLUnZ2dnUVZ8vqdnZ2d@bt.com...
N_Cook wrote:
Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the
phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each
pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from
one
end
to the other , so if made in use would require the diaphragm (spider?)
being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.
Something isnt right here. Are the scored lines on the inside or the
outside of the coil former? Are the windings damaged by the scoring?
If it were the setting shims to blame for the scored lines - which
seems
doubtful they`d use metal, all mine are plastic - they go on the inside
of the coil former. The windings are on the outside.

Take photo if you can.

Ron(UK)
There is no overheating , scoring or any damage to the coil or
elesewhere
just these lines.
http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg
Could someone confirm that the woven and corrugated yellow part I've
labelled purple "S" is called the spider. The cone is to the other side
of
it.
Yes the rear suspension is traditionally refered to as the spider
because in early speakers it was a (usually) three legged tufnol affair
a bit like the '3 legs of Man' mounted insided the v/c and screwed to
the pole piece of the magnet. The v/c was centered by loosening off the
screw and moving the spider around. Often a low frequency (100 hz) (120
in the USA) note was played through the speaker whilst the adjustment
took place

"L" is the lead out of the coil and "G" is some sort of optical guide
laid
in the layup, on the manderel, of the phenolic for placing the lead-outs
to
then meet up with the pigtails at the cone. Moire fringing is where the
coil
is. A second sight guide and second of a pair score line is part in
shadow
off to the upper right.

I dont think that line G is any form of optical sight, just where the
layup of the laminations of the former are recessed to feed the lower
coil leadout up

There is a third and fourth pair of lines diametrically opposite these 2
pairs
I think those are just marks made by withdrawing the coil former from
whatever chuck held it in the winding machine or curing oven - or both.

If there`s no rubbing or burning of the coil, you`ll probably find the
o/c is where the end of the coil passes throught the cone and is
soldered to the pigtail. This is sometimes repairable by scraping off
the glue and reheating the 'blob'. Not worth messing around tho,
replacement speakers like those are cheap.

Ron




If it was scoring from expandable/contractable mandrel or a chuck of some
sort I'd expect it to be engineered and pairs of lines exactly 6mm or
something precise apart, these are about 6 to 8 mm apart and some lines have
a nearby accompanying line. They are white as in scoring not grooves set in
at moulding . Or more likely no marks as what is the point if the process
leaves such serious imperfections where you don't want them.
Click to expand...
I don't know what else it could be then, if it were damage which occured
in use, the lines wouldn't be so precise -a small amount of metal or
grit in the magnetic gap makes a mess. It looks to me as thought the
coil former has been slid off some kind of holder which has left marks
where the contact points were. Are they such 'serious inmperfections'?
you might possibly find every single speaker of that model has the same
marks, and I doubt that they affect the performance of what is in
reality a cheap speaker.

The whole exercise is academic anyway, it`s a ten quid speaker which
almost certainly failed because of some other defect - probably customer
misuse.

I suggest Mr Cook that you are a frustrated forensic pathologist - you
obviously take great pleasure in taking things apart and performing
autopsies,

;) <-----


Ron
 
On Tue, 27 Jan 2009 16:56:04 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

There is no overheating , scoring or any damage to the coil or elesewhere
just these lines.

http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg
Click to expand...
I've often encountered speakers which sound distorted but are still
functional. By moving the cone by hand, I can feel and hear the coil
scraping against something. Would this be caused by blistered
insulation as a consequence of overheating?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:j9b1o4t69ghhmtmvshn9qhp8tjnftjh6t7@4ax.com...
On Tue, 27 Jan 2009 16:56:04 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

There is no overheating , scoring or any damage to the coil or elesewhere
just these lines.

http://home.graffiti.net/diverse:graffiti.net/voice_coil.jpg

I've often encountered speakers which sound distorted but are still
functional. By moving the cone by hand, I can feel and hear the coil
scraping against something. Would this be caused by blistered
insulation as a consequence of overheating?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
Click to expand...

Any bits of swarf or grit, causing lines in service, would be only
half the length of these lines. They extend the whole axial length of the
coil former, into the dome space.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
jakdedert wrote:

Eeyore wrote:
N_Cook wrote:

Due to dirt in use or at manufacture?
Carlsboro 10 inch ,open circuit, so burrowed in to explore. On the phenolic
cylinder that is the former for the voice coil . 4 pairs of scored
ines( stand out white against the amber colour of the phenolic). Each pair
about 6 to 7mm apart and arranged pairwise diametrically.

I suspect 4 pieces of sharp edged metal shim used in the original cone
setting and scored on removal. All the lines go axially , fully from one end
to the other , so if made in use would require the diaphragm (spider?) being
driven 10 mm into the magnet housing. Apart from the nearly symetrical
distribution of the lines.

How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham,

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?
Click to expand...
I discovered it a long time ago and I contribute useful information. N_Cook however
is a twat. He is a self-admitted 'bodger'.

Graham
 
jakdedert wrote:
Eeyore wrote:

How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham

Graham,

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?

jak
Click to expand...

He is a troll on the other electronics newsgroups, and bitches about
everything. He despises anything to do with the United States. He
thinks he is a genius, and keeps bragging about his IQ. Just another
'Skippy' who claims to be the world's foremost audio electronics
designer.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
Michael A. Terrell wrote:
jakdedert wrote:
Eeyore wrote:
How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham

Graham,

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?

jak


He is a troll on the other electronics newsgroups, and bitches about
everything. He despises anything to do with the United States. He
thinks he is a genius, and keeps bragging about his IQ. Just another
'Skippy' who claims to be the world's foremost audio electronics
designer.


A 'skippy'? do explain please
Click to expand...

Ron(UK)
 
Ron wrote:
Michael A. Terrell wrote:
jakdedert wrote:
Eeyore wrote:
How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham

Graham,

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?

jak


He is a troll on the other electronics newsgroups, and bitches about
everything. He despises anything to do with the United States. He
thinks he is a genius, and keeps bragging about his IQ. Just another
'Skippy' who claims to be the world's foremost audio electronics
designer.


A 'skippy'? do explain please

Ron(UK)
Click to expand...

Look at the archives of rec.antiques.radio+phono and you will see the
original 'skippy' in action, before he disappeared. At one point, he
was making threats by telephone. He lost multiple ISP accounts before
he disappeared. He was a self appointed expert on old audio gear, and a
royal pain in the ass.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
Michael A. Terrell wrote:
Ron wrote:

A 'skippy'? do explain please

Ron(UK)


Look at the archives of rec.antiques.radio+phono and you will see the
original 'skippy' in action, before he disappeared. At one point, he
was making threats by telephone. He lost multiple ISP accounts before
he disappeared. He was a self appointed expert on old audio gear, and a
royal pain in the ass.

Ah, there`s a lot of it about ;)
Click to expand...

Ron
 
On Tue, 03 Feb 2009 09:03:23 +0000, Ron <ron@lunevalleyaudio.com> put
finger to keyboard and composed:

Michael A. Terrell wrote:
jakdedert wrote:
Eeyore wrote:
How much time do you waste inflating customers' bills by wasting time on the
pointless ?

Graham

Graham,

Since you've discovered this group, you've done just as little to
contribute as you do on any other. Why don't you just go to bed...and
stay there?

jak


He is a troll on the other electronics newsgroups, and bitches about
everything. He despises anything to do with the United States. He
thinks he is a genius, and keeps bragging about his IQ. Just another
'Skippy' who claims to be the world's foremost audio electronics
designer.


A 'skippy'? do explain please

Ron(UK)
Click to expand...
A Skippy is an Anglo-Celtic Aussie. I always thought Eeyore was a Brit
living in Britain.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
Franc Zabkar wrote:
A Skippy is an Anglo-Celtic Aussie. I always thought Eeyore was a Brit
living in Britain.
Click to expand...

There was a cartoon drawn with a drooling idiot who was called
'Skippy'


--
You can't have a sense of humor, if you have no sense!
 
Michael A. Terrell wrote:
Franc Zabkar wrote:
A Skippy is an Anglo-Celtic Aussie. I always thought Eeyore was a Brit
living in Britain.


There was a cartoon drawn with a drooling idiot who was called
'Skippy'
Click to expand...
Speaking of Eeyore (aka Graham Stevenson) I haven't seen him online for
months, any one heard anything from him?

Ron(UK)
 
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