Yesterday I spoke with a guy at a Russian audio forum who reported that he played with addressing many problems of compression driver by pumping ferrofluid in the gap. I am not a big fun of ferrofluiding generally and in case of compression drivers in particularly.  The main advantages of ferrofluiding: better VC cooling and the VC self-centering can’t not be utilized in compression drivers. Also, the compression drivers mostly are self-damped by the air off back chamber, so ferrofluiding might drive the damping all the way down, converting sound of aluminum into sound of carton.  There are other side-benefits of ferrofluiding, I have no idea how they might manifest themselves in compression drivers. Generally ferrofluiding equalizes dynamics and eats transients – not necessary a bad thing with some compression drivers, particularly with resonating suspension.

I personally never play with adding the ferrofluids. All my experiments with ferrofluid were around taking the ferrofluided drivers, get ring of ferrofluid, add air damping and try to use them in horns. I was not successful but I was a big fun of the drivers before the ferrofluid was removed.

So, what I wonder if anyone played with it and if a SENSIBLE ferrofluiding might be recognized as an additional tool for use with SOME particular off the wall drivers. I for instance would like to learn if the S2 with old metal-suspended cone would be benefited in any way by some kind ferrofluiding. The ringy metal-suspended diaphragms of the S2 driver might be benefited but you never know how those compression drivers would behave…