I've talked to some before about the Schireson Flywheel. Well this morning I'm building one and I'm posting pictures of it in detail. It is in my opinion a great alternative to a biscuit bridge for 6 inch cones.
Note: I use a Tri-Cone replacement cone (left) instead of the standard biscuit cone. For one, it comes in a 3 pack, and it is deeper than a biscuit cone.
The wooden cover plate should have saddle support in the center, and beneath a triangular post the screws to the bottom hole in the cone. I cut a shelved reinforcement that goes around the soundboard resonator well so that the cone rim is slightly regressed into the soundboard. This makes it easier to fit the resonator cover.