EMS speakers are quality products and perform very good as they are. The ones with a field coil motor are true gems for audio. Fast and detailed in sound, affordable to buy.
My friend Cees Pel has been modifying these units for years now, also in cooperation with Musical Affairs and is retired now. As his curiosity and ideas are not retired, he now and then still modifies these. Not for sale purposes, purely to satisfy his curiosity, to explore, to learn. His latest modification has been captured on camera and with his permission these photos are shown below. So maybe others get inspired too or maybe some solutions are presented to people already into modifying activities..
Cees is convinced about old techniques, meaning wooden spiders and hand selected goat leather surrounds. Like they were made in the old days, those very first dynamic speakers. He has some lying around, very old ones, from the 20ies, one age ago. These are still functional and have specific sound qualities that he likes very much. So he reinvents those techniques, by hand, practise patience and precision as that is key. One unit takes about five full days to finish! So no, he is not trying to improve these, he is just exploring possibilities. Catherine and Michel Fertin supply the parts, so he won't have to scavenge new units. They have auditioned his modified units as well and are truly enthusiastic about his craftsmanship. Obviously they do sound different..
Enjoy!