Ferrofluid questions.


I am considering changing out the ferrofluid in the tweeters on my Thiel CS 3.6 speakers. It appears that I should be able to do the work myself. Someone gave a link in another thread to little tubes of the ferrofluid that you can buy for less than $10 from Parts Express.

I have been attributing unclear vocals to my Bryston 4Bsst2 amp being not clear enough. I may still upgrade the Bryston amp to the "cubed" version of the 4B but I’m starting to wonder is it more an issue of my older Thiel speakers’ tweeters having overly resinous ferrofluid.

Could too old of ferrofluid in a tweeter contribute to coarseness in the treble range? What about a slight lack of vocal elocution? I have resorted to using the Soundhound app on my iPhone when listening to vocal music in order to bring up the lyrics. Or, I read the lyrics on the CD cover if they are provided.

If the new ferrofluid improved vocal clarity I would be a very happy guy.

I hope I don’t damage the tweeters in the process.

Also, if you can change the ferrofluid on the tweeter, does the midrange cone work in the same manner?

I look forward to optimizing my speakers further. Thanks for any help you can give.


masi61
I suspect these tweeters are out of production. If you could purchase replacement tweeters of the exact spec they would surely be more than $100! These speakers are at least 30 years old. The sound is still quite good. I’m just wanting to perfect it a bit more.
Thank you @tomic601 I will contact Rob at Coherent Source Audio with the question of ferroflid replacement. 
Just curious: How much are new tweeters? Can't be more than $100 each unless out-of-production.
Original will be more than that, if still made, also never sub them, as the speaker resale will fall off a cliff. 

It'll be $100 for new diaphragms/voice coils if you can get them, and you still have to clean out the old Ferro Fluid from the magnet gap.
So you  may as well just clean the old diaphragm coils as well as save that $100.

Cheers George
Hi OP, I thought you might want to check out our range of Ferrofluid products https://frenergy.com.au/collections/magnetic-ferrofluid. If you have any questions you can check out our product page, the Knowledge page or get in contact with us, we'd be happy to help.
They were made by Vifa and are a metal dome so you have to be very careful not to dent the dome. I would tape something like a tuna fish can over it for safety. Rinse the gap out with electronics parts cleaner like this 
https://www.grainger.com/product/4YPJ5?ef_id=Cj0KCQjw0emHBhC1ARIsAL1QGNfcJANB-xIsHWM6sjm9xZGV44OYOOH...
Until it comes out clear. I'm not sure what kind of seal is in there, probably an "O" ring which you might want to replace. Home Depot has a selection of sizes.
One of the best speakers made in it's day considering the price. Good Luck!
I personally am against ferrofluid now. When the ferrofluid tweeters first came out, I thought it was great and a breakthrough, mainly for the added power handling. After listening to FF tweeters compared to non-FF tweeters, I can say the fluid does affect the sound negatively. Maybe like some have mentioned, various quality and they do tend to thicken over time. I'm now a big fan of ribbons and JBL 2405 type diaphragm tweeters. It would be interesting to hear the tweeters if you decide to clean them out to remove the ferrofluid, before adding new fluid. Maybe reassemble without the fluid and listen at lower volume. I would be very interested in this test should you decide to pursue...