Soundboards

[Ron Nossaman]

Soundboard response is governed by a combination of mechanical impedance
and fundamental resonant frequency. Both of which are determined by the
stiffness and mass of the assembly at different points of the scale. In a
soundboard, the spring back recovery rate of the material should be fairly
high, with a minimum of internal friction. Rib configuration, case shape
and construction, and bridge placement are also important, since the
stiffness of the assembly under the bridge will be different for a bridge
placed closer to the center of the ribs, than for one placed closer to the
rim. These parameters affect the energy transfer rate between the strings
and the soundboard, and it really shouldn't matter what the construction
materials are as long as the finished assembly has a high enough spring
recovery rate, low internal friction so the string energy will be
dissipated as sound rather than heat, and an appropriate stiffness and mass
at any point of the scale. There isn't any physical reason at all that
alternative construction materials couldn't out-perform the vast majority
of all the solid spruce boards ever built. There are psychological reasons
why they would probably be hard to sell, and possible cost concerns,
depending on the materials and assembly methods, but from a performance
standpoint, it's do-able.

A lot of the performance problems of laminated panels come from trying to
just directly substitute materials, using the same construction, without
taking into account the different physical properties of the alternate
material. When it doesn't work all that well, everyone's baffled. After
all, it looks like a real soundboard. To me, it's reminiscent of the early
attempts of manned flight. Birds fly, it looks like a bird, therefore it
must fly. It took the Wright brothers' efforts to define the problems
scientifically before any real understanding and progress happened.
 
Ron N