Ferrofluid


Hey guys. So I have been texting someone from Germany I met online as he also has a pair of B&W 800 Matrix speakers. He mentioned that he treats his tweeters every so many years with Ferro fluid. It was kinda hard to actually text about it online with someone I just met from another county. I did google it and looked on utube for some videos and there are some. It’s seems it should be done about every 10 years or so. And u actually have to take the tweeter out of the cabinet disassemble / remove the voice coil clean out the old Ferro fluid and add new Ferro fluid. It’s seems to be some kind of a magnetic liquid used in speakers especially tweeters for better clearer sound, highs, voices etc. It really looks like a job for the experienced in rebuilding speakers. Has anyone heard of this or had it done ? I’d really love to know from folks who had experience with this. My speakers are from the 90s and even though they still sound phenomenal I’d really like to know more about this. I do plan on keeping my speakers for the long term. Thanks to all in advance. 

128x128Ag insider logo xs@2xtattooedtrackman

Showing 5 responses by katman

There’s nothing inaccurate about a cheap meter, they are all good. I see no relays in that crossover ( or any other crossover ) and diodes generally don’t go bad.

a meter would confirm to op that all caps are good and I bet they are as they used quality components.

I wouldn’t change a thing about the crossovers and I think that is good advice.

Personally, I would not spend a nickel on those crossovers , I’d triamp them but then I have an active crossover sitting in a drawer and the amps to run it, I would not recommend this route to OP.

My only FF experience was when I rebuilt my Boston a400’s. It took me maybe 10 min per tweeter . One had tarry looking FF, the other looked fine - go figure.

I replaced both anyhow. I used a meter ( $20 off Amazon ) to check capacitance of the caps and a few were off so I replaced all with film caps.

You should get meter and check them before replacing . I have a 40 year old set of ads 1230’s and and 42 year set of GNP Valkeryies and both had all caps in spec so why replace them? I’ll read posts of ADS owners sending their crossovers to Richard So to be recapped but why bother if they are fine?

Btw, a good track to show off how good your speakers are is the song by the cars called “Drive”. If they are revealing, after the second stanza , you’ll hear bongos playing a counter melody in the back ground of the “duh duhs”.

No need for a tech, just order a capacitance meter off Amazon $20, put either lead on either side of each cap and see if the number on the meter is with 10% of the number on the cap.

It’s really that simple and you can do both crossovers in 15 min, no chance of damaging anything .

In the time it takes to call someone up and explain what you want you can have one done. But hey, it’s your call.

I don’t want to spin this into a Triamp thread but when I say triamp, I said use an active crossover , not passive .

You can call me a hypocrite as I have my energy 2.8’s passively triamped but I plead innocence as :

1) the manual says don’t use an active crossover with them.

2) I have three NAD 208 amps, might as well use them, right?

No, won’t start another thread. My thought was , if you have a quality, well designed speaker , going to active bi/tri amping is more likely to improve things that 

than trying to “improve “ the crossover which isn’t likely to improve anything . Most likely, in this situation , best thing to do is nothing .

One way to make those speakers sound better is to temporarily hook up an old avr with room correction , turn off all tone controls and try to get freq response flat ( +\- ) by changing speaker location, angle and adding /removing room conditions .

Then, get rid of that avr.