Ferrofluid tweeter misshap!

[Tino]

I had a pair of older blown vifa tweeters which I got from a friend. For a low price, I picked up the replacement diaphrams so I took them off but noticed lots of wood dust (MDF) here and there so I was gently cleaning the motor assembly (with the diaphram off). All was fine until I got to the 2nd assembly. I by accident pressed a bit too hard on the compressed air trigger and the air must have gone into the gap and pushed what I would assume would be about 1/2 a drop to 1 drop of the ferrofluid oil out.

Should I worry about this? Do you think the one tweeter will sound any different than the other with this amount of ferrofluid missing? I guess cooling will be adversly affected too?

Lastly, the old burnt diaphrams also had ferrofluid on the coils (on both). So does this mean that after 1 or two diaphram changes, there would be less oil in there, possibly changing the sound and cooling effects of the tweeter? Can one buy ferrofluid and inject it back into the gap?

Thanks and sorry for the seemgly insane questions

[ashok]

You should check the Voice Coil magazine.
A company had advertised small ( 0.5ml?) refill pouches of Ferro Fluid for tweeter repair applications.
Did you search on Google ?
Damping does affect performance in addition it helps to improve power handling a bit . So you either have both tweeters without it or with it. You will probably will have to clean the other tweeter in any case to remove all contamination by dust etc.
So it now means you have two tweeters with no ferro fluid !!

Cheers.

[hunter audio]

firstly - sound quality

to keep both tweeters performing equally , i am sorry but i have to advise you to remove the ferro fluid

as according to ferro fluid type , tweeter dome replacement procedure you should remove all fluid completely

and add new fluid (comes in small application containers _ for repair purposes ) , 1 of this is emptied entirely into 1 tweeter and a 2nd pouch is used for the other tweeter

if this is not done and _ new fluid is topped up

both tweeters will not sound the same

(even though both has ferrofluid in them ! )

from experience i should also advise that most of the fluid comes out with the burnt dome , therefore a little must be remaining

next

there is not much change in the frequency responce , though the tonal balance may be upset due to damping

next

to protect the tweeters from blowing < if you do not use ferrofluid > you can

affix a 20 watt motorcycle headlamp in series to the tweeter _ after the capacitor

this headlamp should not be halogen and can be any make with a resistance less than 1 ohms

this has been used by jbl in their control series to protect their titanium domes

and by bose to protect his toy cubes

suranjan

[Tino]

Thanks everyone for responding. I'm going to look for new ferrofluid from somewhere. I've looked on the net and could not find any sources so I contacted a manufacturer directly and explained my situation. Maybe they would considering selling me a tiny sample.

Once I have that, I can repair the tweeters. I'm sure that its probably cheaper for me to buy new tweeters but if I can get a tiny sample of fluid, then I can always have some for future use. I have never blown a tweeter myself but you never know....


Tino