Changing Inharmonicity

[jolly roger]

>So what really happened here?  I don't remember the conversation following
the
>demonstration, but I am assuming the steam rearranged the strength of the
>partials.  Roger may wish to comment.
>
>Regards,
>Clyde Hollinger, RPT

Hi Clyde,
               The voicing changes the pitch of the partials,  hence the
beat.  This is clear and easy to hear.   Now the voicing changes the
elasticity of the hammer and hence the dwell time. ( length of time the
hammer is on the string, and how the harmonics develop.)
Oleg is also correct, even blows will also have an effect. Since dwell time
is also effected.   Now enter the weather,  the hammer swellls and shrinks,
with humidity changes
Changing FAC numbers is very sensitive to, weather changes, and felt
compression on a well used piano.
At a guess, I think the changes are more due to humidity and hammer
hardness changes, than board changes.
One way to get an indication.  Sample FAC. (don't play the piano for a
month)  Re sample again after a large humidity swing.
I have done test where the pitch was the same, and the notes were struck
with a constant velocity and mass device.  Cjhanges occur.   But from
what??????   The sampler?  Just the felt? The board? The bearing? The SAT?
Or all of the above?
I suspect all of the above.  No answers just rambling thoughts.

Roger