laminated ribs

[Ron Nossaman]

> But let's assume that are working on a Steinway like piano and you don't
> want to alter that low tension scale but you want to use that somewhat
> firmer hammer in order to produce the balance of partials in the way that
> you want. 

You probably wouldn't want to increase tension significantly 
for structural reasons, whatever sound you might want.


> Presumably you could do this by increasing the stiffness of the
> soundboard spring.  

Yes, the spring rate. A functional CC board has a progressive 
spring rate. It's non-linear, so a little bearing increase 
makes a relatively large difference in assembly stiffness and 
tone production. A RC&S board deflects in a more nearly linear 
fashion, like a beam, so minor bearing changes don't make 
nearly as much difference in tone. It has to be built in by 
design.


>The lower tension string scale now would not be as
> easily capable of moving this heavier rib scale so you would need a somewhat
> harder or heavier hammer in order to impart more energy to the board--which
> is what you wanted.  How you calculate this difference is another matter
> which I leave to the experts design experts I am familiar with.

I don't know about the experts, but deflection calculations 
from string tensions and downbearing, and past experience, is 
the best I've come up with. I'm building higher spring rate 
boards these days that will tolerate a somewhat firmer (but 
still soft by most standards) hammer than those I built three 
or four years ago. I'm not interested in building something 
that needs lacquered hammers to produce tone, if I can avoid 
it, but my early RC&S boards defined too narrow a range of 
hammer choice. I'm narrowing in on a balance I like. Still 
learning.


> My point is that we tend to start from the string scale, calculate a rib
> scale and then figure out which hammer sounds best.  I wonder whether it
> might not make more sense to start with the hammer and string scale and then
> calculate the rib scale that puts everything in equilibrium.  
> 
> David Love

That's pretty much what I'm doing now, though I am under no 
delusions that everyone will be pleased with the result.
Ron N