Soundboard mass

[Ron Nossaman]

> The stiffness of the bridge increases as the _square_ of the height, to 
> that a bridge of 33mm is about 70% stiffer than one of 1 inch and a 
> bridge of 38mm is 33% stiffer than one of 33mm.

Moment of inertia of the section for the flexure formula is 
calculated on the cube of the height, but yes, a little added 
bridge (or crowned rib) height makes for an assembly that's 
considerably stiffer. A similar net effect can be gotten with 
a short bridge with the addition of more crowned ribs.

Ron N