Soundboard stiffness variances

[Richard Brekne]

Hi Jude.

I'm back at the drawing board as well... which is really why I threw out 
that post.  I have my own new project going and I don't expect I'll get 
much help from the RC&S gang.... at least not much more then they've 
already posted through the years.  I wouldn't really expect any of them 
to be interested in trying to find out how to pre-dict the strength and 
stiffness of a compression reliant system as reliably as they feel they 
can an RS&C system. They are more likely to wish the life of compression 
reliant systems me thinks... fair enough really.  To each their own as 
it were.

As for me tho... I'd like to think there was more to the world of 
soundboards then just a set of ribs, and a panel that sits on it rather 
passively no matter what you do to it.... that the world of soundboard 
construction allows for more possibilities then that one approach allows 
for.  Perhaps I am wrong.  So experimentation is of course in order... 
and its going on all over the place really... tho you only hear of a 
small portion of it here on pianotech.

The RC&S camp has showed a very straightforward and quite evidently 
workable way of being able to pre-calculate with pretty fair 
exactingness the strengths characteristics in an RC&S soundboard 
assembly.  It appears to me that CR systems have been arrived at largely 
empirically and that our understanding of just how these soundboard 
systems generate their strengths is not nearly so well understood at 
all.  I've yet to run into a solid answer from either camp as to how one 
can pre-calculate accurately the strengths characteristics of a CR 
system.  Being able to do this seems a pretty tangible direction to 
go... among other directions one could take.  So ... if its a premise 
you need.... I'm working on the premise that it should be equally 
possible to pre-calculate CR system strengths as it is RC&S strengths.  
And if that be true... then we remove entirely from the discussion all 
issues surrounding the comparative predictability of each type of system.

I'm sure your Mason project will yield a lot of increased insights for 
you. The road goes ever ever on as it were.

There is always room for talk... discussion... whilst we carry on each 
with our own projects.  Jogs the mind and helps us on our way.

Cheers
RicB




    Hi Ric,

    I'm still here and still interested. For my part, I ran out of
    things to
    talk about so I'm back to the drawing board. I get to a point where
    I can
    only learn by getting my hands on some work and hearing the results.
    To that
    end, Ron N. and Terry are helping me out with a Mason A6 RC&S
    design. I'm
    hoping this experience raises as many questions as it answers; keeps
    life
    interesting.

    Perhaps we should be talking about what controlled experiments we
    could be
    conducting  to prove, disprove or answer any questions we have.
    While we
    need to start with a premise, talk only goes so far, wouldn't you agree?


    Best,

    Jude Reveley, RPT
    Absolute Piano Restoration, LLC
    Lowell, Massachusetts