Bridge/soundboard relations

[Arlie Rauch]

I'm wondering whether any study or book is available that explains  
the relationship of the sound passing through a given bridge with  
respect to various locations on the soundboard.  This could simplify  
on spot soundboard repairs.

I am working on an ancient Angelus player.  The notes speak well  
except in the lower half of the bass--the vibrations obviously are  
not being magnified.  Could be some other cause, I suppose, but my  
first attention is focused on the soundboard cracks.

Any ideas?

Arlie Rauch