JOSÉ ROMANILLOS 02 | GOOD and BAD Spruce

[rlholo]

I don't think he's saying the fiber transmits waves, but at 6:00 he reveals his point: wood elasticity is better without runout. Well cut wood (seems) to vibrate better. Wood with runout is more brittle and (subjectively) its tone is more brittle. I think it's just that longer fibers can stretch farther and so more comfortably stretch enough to vibrate well. Shorter fibers (the result of runout) are nearer their elastic limit when the wood vibrates, and therefore, more dampened / inefficient.

[vgfigue]

It makes sense. When you hit the wood, you introduce energy on one side of the wood. Ideally, you want that energy to travel through the entire piece of wood, much as you want the string energy to travel through the entire sound board.