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<p class=MsoPlainText>It's not that hard to investigate this sort of thing,
which Dave Carpenter and I did a number of years ago while preparing a seminar
for the Chicago School. I don't have time at the moment to get into a
long discussion of this, but will toss our grist into the mill FWIW.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>I made a toy soundboard, like the M&H device, on
which we could gauge the amount of flex along the grain. It had 3 sockets
for tuning forks: one at 1/2 the length, one at 1/3, and one at 1/4. We put
a vibrating fork in the middle and flexed the board while Dave measured it with
some sort of spectrum analyzer he had lying around. As we gradually increased
the flex, a distinct "node" appeared where the 2nd partial jumped out
of the spectrum--a little more flex and it disappeared. This is the point
where the salesman raises his eyebrows and the customer goes,
"Oooooooo...." A little more flex and another, weaker node
appears for the 3rd partial. Move the fork to another socket and the same thing
happens but at different degrees of flex. Using a different pitch fork does the
same thing with different flex. Dave and I spent the better part of a morning
doing this with different pitch forks accumulating quite a pile of data. When
we graphed it, Dave thought he saw the beginnings of a complex pattern, but all
I saw was a bunch of dots. As Del and Ron have already said, this data
means very little because real soundboards are not crowned along the grain--at
least not nearly enough to produce this sort of effect.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>So make a similar device that can be flexed across the
grain the way soundboards are crowned, and what happens to the spectrum as you
flex it? Nothing.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>Draw your own conclusions.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>Bob Hohf<o:p></o:p></p>
<p class=MsoPlainText>Wisconsin<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
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