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B139 problem

 
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Wouter
Intermediate Contributor 50+


Joined: 18 Jun 2004
Posts: 60
Location: Ramsel (Belgium)

PostPosted: Mon Nov 08, 2004 12:46 pm    Post subject: B139 problem Reply with quote

Hello,

One of my B139 bass drivers has a miss-alignment.
When I place the speaker with the magnet on the table, one side of the flat cone is a little bit higher than the other side.
This results in a little 'noise' when you push in and out the membrane (I think it is the voice coil which slides across the magnet.

What's the best I can do? Re-allign? Buy another one?
I don't know the history of the speaker (bought them second-hand), so I don't know what happened whit this one.

I received a tip, to turn the driver 180 degrees. After a while, the situation would become normally, but I am a little scared that the voice coil becomes damages when it slides constantly to the magnet.

Is this a common problem for the B139?


Best regards,
Wouter
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Gary
Senior Contributor 200+


Joined: 07 Nov 2004
Posts: 275
Location: Toronto, Canada

PostPosted: Thu Nov 11, 2004 9:02 pm    Post subject: Reply with quote

Hi!

I'd presume playing them would eventually damage the voice coil....

I know of someone here in Toronto that can probably fix it. Is there anyone where you live that can fix this stuff?
_________________
Sometimes I lie awake at night, and I ask, "Where have I gone wrong?" Then a voice says to me, "This is going to take more than one night."
-- Charles M. Schulz (as Charlie Brown)
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Wouter
Intermediate Contributor 50+


Joined: 18 Jun 2004
Posts: 60
Location: Ramsel (Belgium)

PostPosted: Fri Nov 12, 2004 4:31 pm    Post subject: Reply with quote

That's what I fear too...
It's just a little noise when you push it (it cannot be heard when music is played), but I fear damage of the voice coil.

I will check some DIY-audio-shops...

Regards,
Wouter
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terry
Senior Contributor 200+


Joined: 22 Apr 2003
Posts: 262
Location: UK

PostPosted: Fri Nov 12, 2004 10:27 pm    Post subject: Reply with quote

There is little you can do other than rotate 180 degrees as the problem has arisen due to sagging. Repair would mean replacing the rubber surround and I suspect you may find it difficult to find someone who will do that.
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Wouter
Intermediate Contributor 50+


Joined: 18 Jun 2004
Posts: 60
Location: Ramsel (Belgium)

PostPosted: Sat Nov 13, 2004 10:23 am    Post subject: Reply with quote

Hi Terry,

Does this happen often with the B139? Is this a common problem?
I never heard about this...

(PS In the meantime I am started with my cabinets for the concerto-speakers!)


Regards,
Wouter
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Gary
Senior Contributor 200+


Joined: 07 Nov 2004
Posts: 275
Location: Toronto, Canada

PostPosted: Sat Nov 13, 2004 8:58 pm    Post subject: Reply with quote

Talking with the Speaker Shop guys, they told me it could either result from misuse or old age. I don't know much about the B139 but it could be an "old age" thing...
_________________
Sometimes I lie awake at night, and I ask, "Where have I gone wrong?" Then a voice says to me, "This is going to take more than one night."
-- Charles M. Schulz (as Charlie Brown)
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Wouter
Intermediate Contributor 50+


Joined: 18 Jun 2004
Posts: 60
Location: Ramsel (Belgium)

PostPosted: Sun Nov 14, 2004 12:13 pm    Post subject: Reply with quote

Yes, that can be... After all, these units are almost 40yrs old.... Misuse, is also possible. I bought them second-hand some time ago, so I don't know the history of these units...

Thanks anyway! I will keep an eye on Ebay for a replacement...
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terry
Senior Contributor 200+


Joined: 22 Apr 2003
Posts: 262
Location: UK

PostPosted: Mon Nov 15, 2004 9:38 am    Post subject: Reply with quote

Old age is the problem if the speakers have been kept in suitable environmental conditions. I have however seen rather corroded B139s which have spent some of their life in humid conditions or in a garden shed!
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Wouter
Intermediate Contributor 50+


Joined: 18 Jun 2004
Posts: 60
Location: Ramsel (Belgium)

PostPosted: Mon Nov 15, 2004 10:05 am    Post subject: Reply with quote

I don't think that the speakers have been stored in extreme humid conditions. The overall condition of all of the six units is very good. No corrosion on the metal, or something, which refers to 'wet conditions'...

I think it would be misuse (pushed in or too much power,...).
Anyway, I will try to get it repaired and in the meantime, I will check regularly Ebay for a replacement-one...

Regards,
Wouter
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