Hi
While I have loads of old speakerunits, I was wondering if a separate thread would be an option,
Using DATS3 , I found out that a lot of them, mostly domes, but also a few paper cone midwoofers were out of spec, I started by taking the domes apart, a lot of them had old ferrofluid in them, that stuck like glue to the coils, removing the fluid, cured most of the wrong specs....but what to do, fill the gaps with new ferrofluid, what type, where to buy, etc.
If possible a bit of knowledge on this subject would be nice, maybe there are more people interested in this.
Cheers, Tom.
While I have loads of old speakerunits, I was wondering if a separate thread would be an option,
Using DATS3 , I found out that a lot of them, mostly domes, but also a few paper cone midwoofers were out of spec, I started by taking the domes apart, a lot of them had old ferrofluid in them, that stuck like glue to the coils, removing the fluid, cured most of the wrong specs....but what to do, fill the gaps with new ferrofluid, what type, where to buy, etc.
If possible a bit of knowledge on this subject would be nice, maybe there are more people interested in this.
Cheers, Tom.
There is a choice of ferrofluids, each defined by its saturation in gauss (G) and viscosity in centipoise (cP).
You'll find more information from the following UK supplier of a ferrofluid specifically formulated for high fidelity tweeters:
https://willys-hifi.com/products/ferrofluid-refill-kit
I doubt the grade matters much... probably a matter of taste. SEAS uses a thin or light one, others may differ.
I have used this cheaper ferrofluid from Blue Aran near Southampton.
You clean out the old stuff with a penetrating oil and kitchen roll on the magnet. Only about 0.1mL required. It also centres the voicecoil apparently.
Enough for 5 small tweeters:
http://www.bluearan.co.uk/index.php?id=SONFF05
Don't know about shipping cost or ability, but you could ring them. There is a good supplier in the Netherlands too, IIRC.
I have used this cheaper ferrofluid from Blue Aran near Southampton.
You clean out the old stuff with a penetrating oil and kitchen roll on the magnet. Only about 0.1mL required. It also centres the voicecoil apparently.
Enough for 5 small tweeters:
http://www.bluearan.co.uk/index.php?id=SONFF05
Don't know about shipping cost or ability, but you could ring them. There is a good supplier in the Netherlands too, IIRC.
Hi
Thanks for the answering, another dome, an Audax from 1982, I took apart and there the foam behind the dome was breaking up and parts were on the coil and so disturbing the coilmovement, what can that be replaced with, any suggestions?
Cheers, Tom.
Thanks for the answering, another dome, an Audax from 1982, I took apart and there the foam behind the dome was breaking up and parts were on the coil and so disturbing the coilmovement, what can that be replaced with, any suggestions?
Cheers, Tom.
Attachments
Just removing ferrofluid is no problem at all. I have literally done it dozens of times without any adverse effects. There is hardly any reason to renew ferrofluid.
Simply wipe the old fluid out with a a folded piece of envelope paper and repeat the wiping until the paper stays clean and no longer shows bits of ff.
Simply wipe the old fluid out with a a folded piece of envelope paper and repeat the wiping until the paper stays clean and no longer shows bits of ff.
Hi
I cleaned the gap, no problem, but should the foam be replaced, with what, I put in a small piece of sound absorbing foam, basotect, seems to work well...
Cheers, Tom.
I cleaned the gap, no problem, but should the foam be replaced, with what, I put in a small piece of sound absorbing foam, basotect, seems to work well...
Cheers, Tom.
I possibly misunderstood your question: if the voice coil assembly of the Audax has attracted pieces of foam, you can clean the vc assembly with alcohol, using e.g. one of those cloth or soft felt (whatever it is ) ear cleaners on a stick.(=wattenstaafje)
The foam can be replaced by a fitting felt piece. Many moons ago my Audax HD12x9 had felt under the dome, and so did a number of Vifa's.
If you've fixed them this is a bit moot.... 🙂
Sounds like the soft sponge or felt pad actually touches the Dome:
http://www.troelsgravesen.dk/large_domes.htm
Trial and error indicated here I think...
You could try a bit of that white BAF wadding you find in speakers and air-conditioning filters.
Or trim some felt to fit without touching the dome.
I use these cheap stick on felt pads from LIDL as speaker feet, but I expect you could cut one to size and use rubbery bicycle inner-tube glue if necessary.
Best, Steve.
Sounds like the soft sponge or felt pad actually touches the Dome:
http://www.troelsgravesen.dk/large_domes.htm
Trial and error indicated here I think...
You could try a bit of that white BAF wadding you find in speakers and air-conditioning filters.
Or trim some felt to fit without touching the dome.
I use these cheap stick on felt pads from LIDL as speaker feet, but I expect you could cut one to size and use rubbery bicycle inner-tube glue if necessary.
Best, Steve.
Answered before I saw your post...the Visatons (25 and 50 mm titanium domes) also had bad foam, with parts on the coils, cleaned those, removed ferrofluid and put basotect in the chambers behind the magnet, I will have to try them out, to see, hear, if they sound ok now
