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<p>Ron Nossaman wrote:
<blockquote TYPE=CITE>>Since string winding tension ect has a large effect
on the harmonic content
<br>>and power, please educate me on how you integrate the bass string
<br>>scaling/design with the Z of the board.
<br>>A direct formula will suffice.
<br>>Regards Roger
<p>* Again, that's scaling, and is graphable and reasonably predictable
in the
<br>design stage. As for the soundboard, I agree. A direct formula would
<br>certainly suffice. Harold Conklin published what he called a characteristic
<br>impedance formula for strings in "Thoughts on Thoughts" in the Journal
that
<br>is quite helpful in scaling. Technicians have always believed in hammers.
<br>They have partially accepted, and are beginning to believe in string
<br>scaling. <b><i>They don't yet believe in soundboards, but when the
right people</i></b>
<br><b><i>with the necessary mathematical knowhow start believing in soundboards</i></b>
<br><b><i>enough to actually explore the possibilities, we'll eventually
be able to</i></b>
<br><b><i>graph that on the spreadsheet too.</i></b> Until then, I have
to go on the basic
<br>concepts of impedance, as introduced by Del, and discussed at great
length
<br>on the list, and personally observed cause and effect relationships.
Kind of
<br>like voicing.
<p> Ron N</blockquote>
Brings up a really interesting point about soundboards that probly most
tuners dont consider much. The soundboard is not just a something that
projects the sounds of the strings as they are played. A soundboard also
has its resonate fequencies or modes. Different degrees of thickness, types
of wood, quality of wood, size and shape of the finished board, etc etc,
will result in a different set of values. Strings that have frequencies
that correspond two these modes or resonant frequencies in the soundboard
will typically have short decay times as the board is very effiecient at
these. String frequencies that are off resonance with regard to the soundboard
have long decay times. We are dealing with impedance matching (strings
to board) here. Decay of the piano tone being varied also means that to
some degree or another the quality / timbre of the sound varies.
<p>Now most of this is way over my head and is of course way more involved,
tho these things are known and known well by some of the better piano manufacturers.
I have not heard that restringing programs take any of this into consideration
(perhaps it is not possible yet or perhaps it is not needed ??). Being
aware of these characteristics of a soundboard, and how to identify them
to some degree with your ear, helps in making decisions with regard to
what field technicians can and cannot accomplish with voicing problems.
<p>Personally, I'd like to know more about all this. Is it possible / helpfull,
to be able to measure the frequency modes of a soundboard when attempting
to rescale and existing piano ? Perhaps this is too expensive or time consuming
?
<p>Nice post by the way Ron.
<p>Richard Brekne
<br>I.C.P.T.G. N.P.T.F.
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