KEF 104.2 tweeter

AX tech editor
Joined 2002
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Hi,

As part of a sale I got a pair of KEF Reference 104.2 speakers. Basically sound except that the tweeters seem to have lost their output.
I found several sources saying that after many years the ferrofluid in those tweeters dries out and the voice coil starts to stick.

So it seems I have a choice of replacing the tweeter (there are non-KEF replacements) or renewing the ferrofluid.

Anybody here who has done this for this particular tweeter?

Jan
 
I have replaced the ferrofluid, I got from some eBay seller.
Disassemble the tweeter are pretty easy.
I cleanout the gap using filter-paper ...takes about 10-15 pieces to remove the old oil
and used some q-tips wetted with some isopropanol to clean the coils

finally used a syring to apply 0.1ml ferrofluid, before re-assemble the tweeters

You might find more info here: Home Page hifiloudspeakers.info
 
Hi,

As part of a sale I got a pair of KEF Reference 104.2 speakers. Basically sound except that the tweeters seem to have lost their output.
I found several sources saying that after many years the ferrofluid in those tweeters dries out and the voice coil starts to stick.

So it seems I have a choice of replacing the tweeter (there are non-KEF replacements) or renewing the ferrofluid.

Anybody here who has done this for this particular tweeter?

Jan

Hi Jan,
Just wondering if and how you progressed with the 104/2's?

asking for a friend :D
Restauratie KEF Reference 104/2 - forum.zelfbouwaudio.nl
 
Disabled Account
Joined 2019
The FF on this speaker is a very light one on the indice and just there for a little help on the cooling side. If you have not the ref take any one but putting vet few : less than the half height.


Or you have this, very close enough if not best, according what you like with music . I find the T33 of the Kef 104/2 I already refurbished once to be forgiving so musical.


I have found this speaker to make music with the acurate strong amp and room size w/o the cube.


if you want a new tweeter, I find this one close enough : Boutique Haut-parleurs & Audio DIY
 
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Joined 2019
... less good imho. Thete is also the Morel 294 at Meniscus iirc but less good too.

One has to measure the impedance of the new tweeter around 3k to adapt the tweeter filter...the 7.5 uf and after...
The Peereless seems a good compromise since the 25tg is non sold anymore.
 
Last edited:
attached measured response of both tweets with ff removed (green, black) and with ff (red). does not look like what it should be
 

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  • SP A & B no ff 2.83V.JPG
    SP A & B no ff 2.83V.JPG
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Joined 2019
measure above 10 K hz is totally another driver than the T33B in the Audax, Morel seems closer but some have experienced better hearting quality in the kef 104 ref with the Peereless DX I linked and its cheaper brother alternative still in the catalog.


now the FF was very light ferro damped so newer may act too much. Also maybe the recoating In the one I refurbished the two original dome had aged differently : one was harder at the finger than the other mellow one ?!
 
Hi nice to see this thread.:D
Bedankt Henkjan voor de voorzet.:cool:
I now have ordered the Audax TW025A2.
The reason for this is that i hope that this unit will be a bit more hold back.
At this moment i have the T33 without the ferro fluit in place and the sound quite aggressive, tuning up the volume is not pleasant this way.
Below you see how the speakers look like at this moment.
Y9CHel7.jpg

When the Audax tweeters are installed i will give you an update of the sound.