Punch holes into lip of sphere opening and tie off wires firmly. Glass or metal spheres require some ingenuity for mounting the speaker. Speaker is now suspended and centered in sphere opening, with the outward firing speaker about 0.1 inch from the plane of the opening and inside the sphere. There is a volume of air around the speaker edges. Do not close this area off.
Performance requires all joints be aIr tight.
0.75 O.D. metal tube to other hole in sphere. Add plunger assembly now or later. Slide the 2.65 inch tube into the wood disc and center the tube with about 1.2 inches of tube on either side of the disc. The disc should fit snugly but should be movable for tuning. Connect speaker to radio or audio source.