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Kef b200g sp1075

 
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Darkwood
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Joined: 02 Dec 2018
Posts: 3

PostPosted: Sun Dec 02, 2018 9:07 pm    Post subject: Kef b200g sp1075 Reply with quote

Hi Iím new member here,
I red a lot of topics here and learned many things about Kef speakers.
Iím a proud owner of kef carlton iii speakers. I bought them as a second hand and they work very good I really like the sound.
But when I open one unit I saw that magnet on one b200g Is little separated from the basket 1mm and someone put a part of toothpick to get it not to move. Could this be repaired? The driver works fine.. I listened it like that almost a year and recently I bought sp1075 constructor series pair as a spare for the carlton. One thing I noticed that the cone isnít as shiny as on ones in carlton. I think that someone pealed off the pva coating on the front or these drivers didnít have any coating on the front at all. Should I coat them and how?

Thank you in advance.
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speakerguru
‹ber Contributor 1000+


Joined: 18 Nov 2005
Posts: 1007
Location: Green Hut, Tovil

PostPosted: Mon Dec 03, 2018 10:18 am    Post subject: Re: Kef b200g sp1075 Reply with quote

Darkwood wrote:
.... I saw that magnet on one b200g Is little separated from the basket 1mm and someone put a part of toothpick to get it not to move....


Welcome to the forum. Could you post a photo?
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Darkwood
Introductory Contributor


Joined: 02 Dec 2018
Posts: 3

PostPosted: Mon Dec 03, 2018 10:31 pm    Post subject: Reply with quote

Thank you for your welcome, here are the pictures.

https://www.flickr.com/gp/143914449@N06/u1zQ9g

https://www.flickr.com/gp/143914449@N06/WRJ7n6

Today I went to my local repair guy he says that he can remove the silly thoot picks and glue the magnet without driver disassembly. Dont know will that work.

Here's the photo of the drivers, see the diference in shinines.

https://www.flickr.com/gp/143914449@N06/GC118b
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speakerguru
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Joined: 18 Nov 2005
Posts: 1007
Location: Green Hut, Tovil

PostPosted: Tue Dec 04, 2018 10:03 am    Post subject: Reply with quote

I see. Something must have gone wrong when the chassis was attached to the magnet assembly. Normally the action of staking the semi shear pins on the top plate (of the magnet) forces the chassis down hard onto the top plate. In this case a gap remained on one side. Nevertheless, if the driver made it through the rest of the production process and testing, I would assume the chassis is rigidly fixed, albeit at an angle, and not rubbing.

In which case I would leave it alone or maybe just put some high viscosity superglue around the toothpick to stabilise it. Do not use any adhesive that might run down into the voice coil gap.

Re the front coat; it was mostly a thin, cosmetic layer on the front. There will be three coats on the back which do the bulk of the cone damping. You could put on a thin coat of any PVA type glue but I doubt you could get that smooth look by brushing. I can't recall atm how they did get that smooth finish in the factory. I would not have been possible to spray after the surround was put on, and the surround would not stick if the cone had been sprayed first.

In short, as we used to say at KEF, "if it ain't broke, don't fix it"
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Darkwood
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Joined: 02 Dec 2018
Posts: 3

PostPosted: Tue Dec 04, 2018 12:51 pm    Post subject: Reply with quote

Ok thank you very much i will leave it alone.
One more thing what pva should i use? What should I buy - henkel moment wood waterproof or regular one or some cheap one, and should I dilute it with water?
Btw the other bass in the cabinet has recone sticker from some company in Holland it says it was reconed in 1997. But i think itís only been centered i cant see that someone removed the spider or spool because it has original glue on it and the wires are stapled to the spider and glued just like the other one. I also noticed that one spider has more yellowish collor then the other could it be that it was changed or is it factory like?

These kef speakers are very musical but highs are not that precise, is it due the soft dome of t33a because when i touch it slightly itís very soft. When i bought spare constructor series b200g bass drivers I also bought with them t33a tweeters but they have thicker membrane on touch?

I also have one pair of monitor audio ma4 with kef sp1039 drivers and isophone kk8 tweeters and they are crispier sounding.
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speakerguru
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Joined: 18 Nov 2005
Posts: 1007
Location: Green Hut, Tovil

PostPosted: Wed Dec 05, 2018 9:50 am    Post subject: Reply with quote

Darkwood wrote:
...One more thing what pva should i use? What should I buy - henkel moment wood waterproof or regular one or some cheap one, and should I dilute it with water?

see http://www.hifiloudspeakers.info/speakertalk/viewtopic.php?t=1655

Darkwood wrote:
... the other bass in the cabinet has recone sticker from some company in Holland it says it was reconed in 1997. But i think itís only been centered i cant see that someone removed the spider or spool because it has original glue on it and the wires are stapled to the spider and glued just like the other one. I also noticed that one spider has more yellowish collor then the other could it be that it was changed or is it factory like?

spider colour varies from batch to batch. Depends on how long they have been baked - like bread. Could have been reconed with a coil-cone assembly from the factory?

Darkwood wrote:
These kef speakers are very musical but highs are not that precise, is it due the soft dome of t33a because when i touch it slightly itís very soft. When i bought spare constructor series b200g bass drivers I also bought with them t33a tweeters but they have thicker membrane on touch?..

Soft dome tweeters should be "soft". That is how the mechanical resonances are damped. Maybe there has been some deterioration with age, damp, fungus, etc.
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