I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

"JCBrunelli" wrote in message ...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

I think it's called "ferrofluid". It's main purpose is to conduct heat
away from the voice coil. If you remove it, you'll have to replace it.

It's called Ferro Fluid. It's a magnetic fluid that dissapates the heat and
increases the power handling of the tweeter. The amount is supposed to be
the same in both tweeters as it has an effect on the physical response of
the tweeters.

Mark T.
"JCBrunelli" wrote in message
...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

Don't dry it out, leave all you can. This is ferrofluid, which provides
added power handleing and damping to the tweeter. Its effect is part of the
reponse of the tweeter, which I assume you do not want to change away from
the manufacturer's intended sound qualities..

Wylie Williams

"JCBrunelli" wrote in message
...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

JCBrunelli wrote:

I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

That sounds like Ferrofluid. It is supposed to help conduct heat from
the voice coil to the surrounding magnet structure; and perhaps to
provide some mechanical damping to the voice coil.

-Gene Poon

(JCBrunelli) wrote in message ...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

This is the famous "ferrofluid" that you have undoubtedly heard of. It
floats around in the magnetic gap but does get on the voicecoil if you
remove it. What's best is to not dry it up and just put it back. Most
likely what you see represents a minority of the total fluid still
present in the gap, although this is not absolutely certain as some
tweeters tend to scoop out more than others. If by doing the surgury
you did some FF got smeared in other places you can wipe this off. It
should be on or very nearby the coil, nowhere else. After
investigating this a quite few times I found that there are ussually
no audible or significant measurable differences after doing something
like this. You should be just fine.

You should avoid potential generic audiophile advice from some who say
that ferrofluid doesn't sound better etc and to remove it. It's true
that you see much less of it these days in the upper range drivers.
The tweeter was designed to have it in there so if you would remove
it, the chances are good the frequency response will be linear, but no
longer neutral (flat). I like your tenacity to do this, it's fun to do
that kind of stuff isn't it?

Wessel

In article , says...
"JCBrunelli" wrote in message ...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

I think it's called "ferrofluid". It's main purpose is to conduct heat
away from the voice coil. If you remove it, you'll have to replace it.

Not really.
The tweeter will work fine without it; actually, most sound better without
it.


--
Whenever I consider my mortality and ask myself what I would do if
I only had a short time to live, an intrinsic part of the answer is,
Get the most musical pleasure.
- Dr. Gizmo

Gene Poon wrote:




JCBrunelli wrote:

I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

That sounds like Ferrofluid. It is supposed to help conduct heat from
the voice coil to the surrounding magnet structure; and perhaps to
provide some mechanical damping to the voice coil.

-Gene Poon

For the record Ferrofluid is a brand of magnetic oil (oil with magnetic
particles in suspension) in the voice coil. As mentioned it assists in
damping, cooling and it seals the "hole" in the gap.The magnetic particles keep
the oil from leaking out of the gap.

On 4 Oct 2004 23:51:02 GMT, Dalibor Bauernfrajnd
wrote:

In article , says...
"JCBrunelli" wrote in message ...
I own a Moudaunt-Short MS10i Classic bookshelf loudspeaker. Recently
one of the tweeters stop working. I was able to fix it since it was a
broken wire in the coil connection. However, in this disassembling
process I found (in the two tweeters) a dark brown liquid inside the
circular groove in the magnet where the coil is supposed to stay. Is
this liquid part of the tweeter mechanism (and the coil is dipped on
it) or is just moisture accumulated over the years? I am afraid to dry
it up. Any help would be very welcome. Thanks very much. Jose Carlos
Brunelli

I think it's called "ferrofluid". It's main purpose is to conduct heat
away from the voice coil. If you remove it, you'll have to replace it.

Not really.
The tweeter will work fine without it; actually, most sound better without
it.

That is *very* bad advice. While many will argue that tweeters which
do not use ferrofluid sound better than those which do, this is a very
different matter from *removing* ferrofluid from a tweeter which was
designed to use it. At best, you'll get a ragged frequency response
with a severe resonance peak (which had been damped by the
ferrofluid). At worst, because the fluid is largely a heat conductor,
you'll fry the tweeter voice coil.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

You should avoid potential generic audiophile advice from some who say
that ferrofluid doesn't sound better etc and to remove it. It's true
that you see much less of it these days in the upper range drivers.
The tweeter was designed to have it in there so if you would remove
it, the chances are good the frequency response will be linear, but no
longer neutral (flat). I like your tenacity to do this, it's fun to do
that kind of stuff isn't it?

Wessel

Thanks for the reply. Yes it was fun and I was very lucky being able
to fix it. I do not understand how this thin wire broke but some of
the fluid reached external areas (maybe by some capillarity process)
far away from the gap and coil.

JCBrunelli wrote:

...I do not understand how this thin wire (to the tweeter voice coil) broke...

Probably just flexing over a long period of time, perhaps helped along
by extreme excursions of the tweeter dome. It is not that uncommon a
fault, and splicing or soldering the wire occasionally is necessary to
fix a speaker at all, if the tweeter is no longer available from its
manufacturer. It does take good eyes and steady hands.

-Gene Poon

Gene Poon wrote:
JCBrunelli wrote:

...I do not understand how this thin wire (to the tweeter voice
coil) broke...

Probably just flexing over a long period of time, perhaps helped along
by extreme excursions of the tweeter dome. It is not that uncommon a
fault, and splicing or soldering the wire occasionally is necessary to
fix a speaker at all, if the tweeter is no longer available from its
manufacturer. It does take good eyes and steady hands.

-Gene Poon

I had a lot of failures with burnt dome tweeter voice coils once. It turned
out they always blew at the bend where the wire went underneath the coil to
go upwards to the connection. That bend was so sharp, that the conducting
diameter went down, heating up too much and burned away. I talked to the
manufacturer, who changed the method and voila- no more failures.
--
ciao Ban
Bordighera, Italy