Ferrofluid

Ok.  So I just got off the phone with Bill from Miller sound. Very nice guy BTW. He said that he definitely does that it is very responsible $105 ea tweeter. But he said to be extremely careful shipping them if I can’t make the 2.5 hr drive to PA from NJ where I am. But —— he said IF I still hear good and loud treble with my tweeters they are definitely still good with the ferro fluid and he advised me not to touch them. BTW last night before I even heard about this Ferro fluid thing I was up in my music room for about 5 hrs enjoying my system and I decided to take all 6 speaker covers off and listen for the rest of the time with them off. And as I was listening to the Cars - Dangerous Type , btw I love the drums thundering and exploding on that song with my speakers. So i definitely heard the great loud detailed treble on both tweeters. So I will definitely take Bills advice and until I hear anything different ( negative) with them I’ll leave them be. Bill also mentioned a place closer to me in NYC that he recommended that does great work on speakers too. It’s called Technetron. That way I could bring them in instead of taking a chance and shipping them and having them get damaged in the mail which I very much appreciated him telling me that also. 

There is no set rule regarding how long ferrofluid lasts.  I have read 10-15 years is typical.

Chances are your ferrofluid is still basically still ok and you will hear little or no difference after having it changed, but who knows.  My speakers were also built in the 90's, and I think it is wise to change the ferrofluid to ensure no damage.

About the crossovers, I will leave it to the experts here to recommend whether or not to update them if they still sound great.  The question is if crossovers with high quality parts like your (and my) speakers last longer than those with more generic parts?  A quality repair guy once told me he thought they do.

Better yet, see if you can talk with B & W about the advisability of updating the crossovers or not. 

@jetter Right now I will hold off and put the ferro fluid on the back burner. I’m just very glad to know more about it and more importantly where to go to have them serviced. About the crossovers. I found a guy on EBay who makes crossovers from original speaker schematics using all much higher quality caps and resistors than originals including better wiring etc.  Says as follows. This auction is for B&W brand 800 Matrix. This auction is for a pair of new crossovers. They are built to the original schematics with the improved parts quality and some small tweaks to take the speakers to another level of sonic purity.  Service provided   Full crossover upgrade. Replace capacitors in tweeters with premium film capacitors. Replace midrange capacitors with poly film capacitors. Replace tweeter/ midrange resistors with film type resistors. Replace all capacitors in woofer section + film bypass. Replace woofer inductors with 14/15 awg steel low distortion core inductors. Replace midrange inductors with air core low distortion type. Replace all resistors with higher power type.  In return you will get more powerful better extended low frequency , more dynamic clearer midrange. And smoother higher resolution highs. The speakers will come to life with more detail and dimensions.  20+ years of experience in high fidelity crossover design. He has a lot of great reviews with his crossovers. I was emailing him last night and seems very knowledgeable and gets back to you right away. He also offers a 3 year warranty. And said his crossovers will be good for at least 30 yrs. His username is Crossoverchef-com   Check him out.