Soundboard Construction Methods

[Ron Nossaman]

> By the nature of the barred and crowned soundboard, no matter how it is 
> constructed, there will be compression ( or, in extreme cases, a 
> reduction in tension!) at the top of the system on the one hand when the 
> necessary radial pressure of the strings comes into effect and on the 
> other as the moisture content of the board exceeds the moisture content 
> at assembly.  What distinguishes the various methods is the _degree_ of 
> compression and in particular its proximity to the yield point of the 
> wood across the grain.

All of which we have said enough times in enough ways that 
everyone should have long ago had a firm grasp on the concept. 
Yes, there will likely always be some compression at some time 
in all panels. How much is there initially can only be 
indicated in a relative manner by noting the MC at assembly, 
the assembly method, the degree of deflection after stringing, 
and the MC at the time of the estimate. The difference, yet 
again, is that in RC&S assemblies, that compression is 
intentionally kept well below the immediate yield point of the 
panel material, and the ribs are supporting the string bearing 
rather than panel compression supporting both string bearing 
and bending the ribs to form crown, as in CC construction. 
That's it. The story isn't ever going to change because that 
is what it's about. No one is ever going to have compression 
figures for you or anyone else because they will be different 
in every panel, and in different sections of each panel as a 
result of changing atmospheric conditions, non uniformity of 
materials, and a never ending swamp of essentially irrelevant 
details. The people building RC&S assemblies frankly aren't 
interested in this infinite minutia, any more than are the 
people still building the CC boards. The RC&S people are 
implementing what they consider to be improvements in 
construction methods to improve predictability of results and 
longevity of the assembly in use. If they didn't like the 
resulting sound, they wouldn't be doing it, much less 
repeatedly covering the same ground with the same people from 
the same starting point in explaining the concept. We're 
trying to expand what we've already learned and take it where 
it can go by building soundboards to the principals we've 
outlined here.


>A long time ago asked a friend who has principal pianist with the 
> Shanghai Symphony Orchestra what it was most that led him to prefer the 
> Steinway, and his answer was that a Steinway "has bones".  I knew what 
> he meant and I know now that "bones" (and I don't mean ribs!) is _one_ 
> of the essential qualities of the piano tone that I seek out and aim to 
> reproduce.  Without bones, other essential qualities of the modern piano 
> sound that _I_ aim for cannot be properly developed.

But let's don't muddy the waters.


> Now my experience and taste suggest to me that the qualities I am 
> looking for are closely connected to the state of compression of the 
> soundboard.  I am at a disadvantage in not having had direct contact or 
> heard recordings made with pianos whose soundboards are made by 
> variations of the "RCS" method.  To say I am open-minded would be mildly 
> hyperbolic, but I'd like to know where I can hear them on-line.  My mind 
> opens and changes very promptly when I get evidence to dispel my illusions.
> 
> JD

Kent Swafford posted recordings of comparisons two months ago 
on this list.
Ron N