This will be a "build" thread. I have 2 8" Magnat drivers, and 4 10" SDK-10 Aguiar(eminence) the Magnat's just need re edgeing, and the kits just came to re edge with butly rubber instead of foam. These take the "angled" kind of foam, and they are an odd size, slightly larger than a normal 8. First here are some before pictures, and some after cleaning pictures, they I'll post step by step. The reedging will be easy, the reconing I might screw up. So here are the Magnat drivers
Ummm, butyl rubber surrounds have a completely different property than the closed cell pressed foam. There's no way in hell that the TS parameters will be even remotely close (assuming you know what the original ones were). The moving mass is much greater and there is less damping (ie. more bounce) in the material. Did the supplier provide the necessary shims and dustcap?