Tannoy i12 diaphragm replacement with ferrofluid 

This is how I did it. There doesn't seem to be any rule-of-thumb directions out there. This is just another opinion to consider in the DIY world. The European gear can be very expensive to obtain parts. After hours of research, I felt very comfortable with this procedure. Sorry about the video quality. I did this all while trying to work and hold the camera. For those that want the rest of the story, Tannoy uses Ferrofluid APGS15N if you just wanted to order some. Syringe comes with 0.3ml. I would prefer about twice that much.