How do you shield a Center speaker?

Bucking magnets......Parts Express carries them.

I have seen those "bucking magnets" and I wonder how they affect the performance of the driver you put them on. I would prefer the shielding approach.

Most manufacturers that shield their speakers use the bucking magnet approach, it's simple and effective. Any change in the Q of a driver is too small to make any difference and will not be noticed by your ears. IMO, lining the inside of a speaker cabinet with metal is bound to change the tonal characteristic of said speaker for the worse. Manufacturers strive to have inert cabinet interiors, not highly reflective surfaces.

Will sheilding taped to the outside have any effect? It seems the simplest (maybe not the prettiest) solution.