Many years ago, I owned a pair Janszen Z960 speakers, which used the same woofer as the Z600. I am not sure if Janszen made the woofer, or had it outsourced. The only thing about the speaker in the photo, that looks like the original
is the orange colored surround. The original woofer had circular ridges over the cone area. You can google "Janszen 350D woofer" and get some photos of the original.