The Curse of Ferrofluid

[stuwils]

How do one replace the ferrofluid?

see my thread in DIY with link to youtube video.

Meridian tweeter repair

I noticed recently that one of my 25 TAFC/GW-BS1 H1054 - 6 Ohm (Black Dome) tweeters had reduced output and had gone "soft ", switching tweeters confirmed that it was only this tweeter that was affected. I brought out my reserve H539 that was OK 3 years ago only to find that it too has reduced...

pinkfishmedia.net

Rgds
Stuart

 

[Beobloke]

So, by extension, you won't have liked most of the 70s Goodmans models, Minster, Havant, Magnum, Magister, Dimension 8, etc, as these all used the DT3 AFAIK?

No, I'm not a fan of any of them, with the exception of the Dimension 8s and I think that's because you're effectively listening to the tweeters off-axis, which tames them a bit! The Magisters are especially bad, in my opinion - both pairs I've owned came with blown tweeters - I sold the first pair for spares as I was unable to find any tweeters at the time, but the second pair i managed to source a good working set. A friend and I listened to them with no tweeters initially and though they sounded promising, When I fitted the DT3s we both agreed they sounded nicer without them!

Interestingly, the best DT3-equipped models I've heard were the Achromats. The Achromat 400s used a surprisingly complex crossover, which was unusual for Goodmans, but they had an odd tonal balance in the midband which was a shame. The Achromat Sigmas were by far my favourites and I still think are one of the best of any of the old Goodmans speakers. I'd love to re-visit another pair but most that I see these days seem to be knackered and/or have non-original drivers.

 

[Mr Pig]

I only found out recently that there is different kinds of ferrofluid. Just chucking any old kind in might effect the sensitivity of the tweeter.

Linn originally used units with no ferrofluid then switch to ones with. Very noticeable change in sound with pros and cons for each. Reliability is harder to gauge but my later tweeters are all still working.

Naim used the same units in the SBL etc with no ferrofluid.

 

[James]

I prefer to avoid ferro-fluid cooled tweeters. One of the finest sounding 19mm tweeter is the Hiquphon OW-1, which does not have ferro-fluid. I also believe neither the tweeter or dome-midrange of my 40+ year old Yamaha NS-1000Ms are ferro-fluid cooled, and they sound just fine.

 

[davidsrsb]

I prefer to avoid ferro-fluid cooled tweeters. One of the finest sounding 19mm tweeter is the Hiquphon OW-1, which does not have ferro-fluid. I also believe neither the tweeter or dome-midrange of my 40+ year old Yamaha NS-1000Ms are ferro-fluid cooled, and they sound just fine.

Ferro-fluid cooling becomes necessary with 25mm tweeters crossed over a bit low, so a lot of power in the music. Three ways really should not have the issue.

 

[Sue Pertwee-Tyr]

How do one replace the ferrofluid?

Drill a small hole and get a big magnet

 

[Paraheadache]

I have a pair of bw dm7 Mk1 which I've had from new. They mainly live in the spare room but every now and again I put them in the main system for a month or so and they just sound great to me.

 

[timpy]

I have a pair of bw dm7 Mk1 which I've had from new. They mainly live in the spare room but every now and again I put them in the main system for a month or so and they just sound great to me.

Other people with speakers in the spare room do tend to make me feel better.

PS
My spare room speaker count = 9
That is just the spare room though.

 

[Paraheadache]

Other people with speakers in the spare room do tend to make me feel better.

PS
My spare room speaker count = 9
That is just the spare room though.

Yeah I've got 4 pairs in there i love a bit of rotation

 

[Fatmarley]

The ferrofluid in my Mission 731i tweeters was dried up (and the capacitors were miles out of spec).
They were a pain to disassemble (glued together), but sound much better now.

 

[timpy]

Ferro-fluid cooling becomes necessary with 25mm tweeters crossed over a bit low, so a lot of power in the music. Three ways really should not have the issue.

I wondered about this, i.e. whether it was for sensitivity or power handling.
The GR Research design I had in mind, has the tweeter play down quite low (XLS-Encore) and has no ferrofluid in it. Of course, that may be restricting ultimate power handling.

 

[Beobloke]

Other people with speakers in the spare room do tend to make me feel better.

PS
My spare room speaker count = 9
That is just the spare room though.

I have no speakers in the spare room.

I do have 10 pairs in the listening room currently, 3 pairs boxed in the loft and 9 pairs in the workshop, though...