impedance and empericism -- longer

[Richard Moody]

----- Original Message -----
From: Delwin D Fandrich <pianobuilders@olynet.com>
To: <pianotech@ptg.org>
Sent: Tuesday, June 27, 2000 8:49 AM
Subject: Re: impedance and empericism -- longer


> >
> >
> > > >> Sound boards *do* affect inharmonicity--and they are affected by
> relative
> > > >> humidity. .
> > > >>
> > > >OK, perhaps soundboards DO have inharmonicity.
> > >
> > > Ric,
> > > That's not what he said. What was said is that soundboards **affect**
> > > inharmonicity. .....
> > > Soundboards **may** indeed have what might reasonably be called
> > > inharmonicity ,... but that hasn't been suggested yet.
> > > Ron N
> >
> > OK, Then I am suggesting perhaps soundboards DO have
inharmonicity. ---ric
> >
> --------------------------------------------
>
> Meaning what, exactly?
>
> -- ddf
>
I suppose you would have to conduct experiments to determine if the
statements of Ron and I are true, not true, or kinda close but not
definitive.

Ron said "Soundboards  **may** indeed have what might reasonably be called
inharmonicity "

I said, " OK, Then I am suggesting perhaps soundboards DO have
inharmonicity.

You ask, "Meaning what, exactly?"



I am asking if soundboards DO have inharmonicity?   If so, how do you find
out how much?   We have the experiments of R. Young for steel strings.  If
suggestions of Ron and I for Ih for soundboards are true, they would have to
be verified by experiment.  But how would these experiments be set up?


,... This discussion started about humidity affecting inharmonicity.   I
noted that the research on inharmonicity only considered it as an effect of
a vibrating steel wire.
No parameters were given to include effects of humidity.  Now inharmonicity
readings from ETD's are apparently different from day to day.  What is
causing the difference?
    I say that if a vibrating string has inharmonicity due to stiffness and
diameter, then a vibrating sound board MIGHT have inharmonicity in itself
due to stiffness and diameter.(thickness).
    If the concept that strings have inharmonicity can be followed why can't
soundboards be investigated for their own inharmonic properties.   I am not
saying they DO have Ih,  only they MIGHT.   The real question is, "Do
soundboards have inharmonicity?"
    Or from another angle, are the partial frequencies of vibrating
piano wire affected by humidity, or are the partial fequency readings
affected by humidity on the soundboard?  We need to devise a simple
experiment.  Compare the partial readings of a string between two clamps to
one of the same length on a sound  board.  Keep a record over varying days
of humidity and temperature.  Which changes the most?   Is this a valid
experiment to arrive at an understandingof the effects of RH on IH ?
---ric