Killer Octave CC & CC&R

[Frank Emerson]

I think the most common error in piano manufacturing is the inevitable
notion that if more is good, then a whole lot more must be even better. 
Conversely, if lower RH is good, even lower must be better.  4% RH in
soundboard work seems like too little to me.  Some factories insist on
nothing less than 6%.  Others insist on no more than 5%.  This may seem
like splitting hairs, but it is critical.  It has been argued that the
exact species must be factored in, some requiring more and others less RH. 
Ultimately it comes down to each individual factory's experience with their
particular material and methods, and the extent to which they experiment
and measure the results of multiple variables.  I have insufficient
knowledge or experience to back this up, but it has been suggested to me
that Sitka spruce requires a lower RH, while Eastern Canadian spruce
require a slightly higher RH.  I cannot speak to the best RH levels for
European, Russian, or Chinese species, but certainly more study of these
species is need.  Like it or not, more and more pianos are being built with
materials from these regions.

Frank Emerson