Kef Reference Tweeters-Ferrofluid Replacement

It took me three months to build up the courage to replace the Ferrofluid oil in my Kef tweeters.
There were several good videos on the internet how to go through the process, one in particular out of Texas. 
There were no videos or instructions which directly related to my specific speakers; Reference 3~2.
They are ~ 20 years old and I noticed that the highs were muddy and dull in the right speaker.
I run a Cardas Frequency Sweep record every 6 months or so.  The tweeter issue was noticeable during this maintenance procedure.
No replacement speakers (tweeters) are available from Kef or anywhere on the internet, so one wrong move and the speaker system would be worthless.  I felt like I was performing brain surgery.

First speaker took ~ 3 hours.  Second about 30 minutes.
I am happy to announce that the 'oil change' was successful!
The speakers are back to full factory operating specifications.
I've attached a link with some photos below.
If anyone needs to perform this procedure I can help walk you through the process.

Take care,


Showing 7 responses by quincy

Yes, same place I purchased mine!

I had no idea how many or how much when I did mine.
I bought six, used two.

So, to answer your question, one packet per tweeter.

Its amazing stuff.  The tweeter magnet just grabs the ferrofluid and it distributes itself around the entire annulus via magnetism.

Don't forget to clean off your voice coil with q-tips saturated with rubbing alcohol.   You need to get all the old gunk off.  Be gentle!

The tweeter needs to be gently pushed out forward from the mid range speaker once you pull the screw and rubber washer out.  Use a 1/4 drive extension about 6" long.  You will need to un-solder the small, thin wires first or the tweeter will not come out far enough to work on it.  Purchase a small electronic soldering iron for this purpose.  Use a pair of small electronic needle nose pliers to help get the wires out once you melt the solder.

Carefully remove the tweeter dust cover using a 'eye glass' flat bladed screw driver.  There are 2 small gaps for this purpose.  The voice coil is right under this 'cap'.  The voice coil is actually immersed into the Ferrofluid.  It sits into the groove annulus of the tweeter.  So, I can now understand how this system works.  The Ferrofluid is used as a lubricant and coolant for the operation of the voice coil.   I'm not 100% certain, but I believe the voice coil dithers up and down some how in this groove to create the high frequency. 

Use great caution.  Everything is very fragile!  Good luck!  Let me know how you make out.   
The voice coil sits in the fluid.  
Yes, I cleaned it.
Q-Tip with rubbing alcohol in a circular motion.  Very gentle!
Both inside and outside diameter was cleaned.

I did not remove the voice coil entirely from the speaker body.  Enough slack is avail in the wires to lift it out an off and to one side.  See photo.
Hello Alex,
I will try my best to assist you in your rebuild of your Kef speakers.
The black plastic 'diffuser'  (not sure what it is called) is held on with Allen head hex screws.  Six each speaker in my case.  Borrow or purchase a inexpensive set for this process step.  It has to come off, you can't get to the speakers with it in place.  I had 6 plastic plugs that were in front of (on top of) the allen hex screws.  I saw no purpose to these 'plastic plugs' other than to confuse you about the disassembly process.  I did put them back because, well, you just never know.....  You can get the plugs out by jamming a phillips head screwdriver into them and rotating counter clockwise.  These plugs are not attached to anything, only a press fit.  I often wonder how many folks stopped at this stage because of the confusion created.  No written or visual instructions exist, that I could find anyway.  That's why the first speaker took me 3 hours of 'discovery'.
Okay Alex,

Any thing else just ask away.

Don't know if its possible, but if you send a pm, I'll supply my phone number and try to help that way if you wish.

Good luck!
Thanks for the additional info and support guys!
Please post the contact information for others in regards to the company authorized to work on Kef equipment.  Phone, e-mail address, etc.

Good luck reassembling everything!