I have three 435be drivers and two of them need a little work. With the diaphragms removed I saw that there was what looked to be a little metal specks in the coil gap. I cleaned the coil gap quite well and now need to replace the ferrofluid. What should I be purchasing? Also I am in need of one of the O-rings that goes around the diaphragm and holds it in the back chamber. I hope that makes sense.
Here are some photos of the O-ring and you can see it installed with the diaphragm in the back chamber.
Thank you,
Dan