The main problem with these B&W tweeters is that the neodymium magnet loses its coating, causing particles to obstruct the air gap. Repairing the magnet assembly itself is virtually impossible.
(The dried-out ferrofluid could, in principle, be replaced.)
This repair service involves bonding a sonically impressive tweeter (manufactured in Europe) onto the original tweeter faceplate. Consequently, this is not a factory-standard repair.
(The first two images show the modified tweeter. The subsequent images show the original magnet assembly with flaking coating obstructing the air gap.)
The conversion of the tweeter costs 180.- CHF per piece
The professional facilities and large stock of loudspeaker spare parts make us the leading provider of loudspeaker repairs in Switzerland.
Further information and pictures at: speakerrepairs
Procedure:
You remove the defective tweeters from the box and send them to us by mail.
(Since this offer is a service/repair, it cannot be ordered directly online...)