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Delwin D Fandrich wrote:
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<div style="FONT: 10pt arial">----- Original Message -----</div>
<div
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><b>From:</b>
<a href="mailto:Richard.Brekne@grieg.uib.no" title="Richard.Brekne@grieg.uib.no">Richard
Brekne</a></div>
<div style="FONT: 10pt arial"><b>To:</b> <a href="mailto:pianotech@ptg.org" title="pianotech@ptg.org">pianotech@ptg.org</a></div>
<div style="FONT: 10pt arial"><b>Sent:</b> December 04, 2001 12:20 PM</div>
<div style="FONT: 10pt arial"><b>Subject:</b> Re: Modal Analysis (was Negative
bearing (long))</div>
Phil, Ron, and Del.
<p>Here is a page from the text of Wograms article that addresses directly
I think Phils remarks, and what I interpret as his assertion of the predictability
of modal analysis from the unloaded to the loaded conditions. I would highly
recommend this whole article to anyone interested or directly involved
in work relating to soundboard impedance issues. Even for someone like
me who just wants to gain better insights such reading is valuable... so
read away folks..</blockquote>
<p><font color="#000080"><font size=-1>Yes, Richard, I have the book and
I've read the article. As I have said several time, my experience was some
different.</font></font>
<p><font color="#000080"><font size=-1>Del</font></font></blockquote>
<p><br>Sorry if I seem er.... eager to help..... but it seemed like you
said you had very limited experience with Wograms experiment and had little
knowledge of his work and that you based your tentative skepticism to modal
analysis on just one piano and that on the other hand you had learned quite
a bit from that one experiment about soundboards in general... all that
seemed just a little vague so I threw this out.
<br>
<p>you reply to Phil kind of matter of factly about this again when you
say...
<br>
<blockquote>"I can't see any advantage to this. Other than as a teaching
aid to help
<br>understand how the soundboard works. It is only going to illustrate
at what
<br>point the soundboard resonances come in and what their shapes are.
Again,
<br>this is with an unloaded board. Everything is going to change once
the
<br>strings go on and their up to pitch."</blockquote>
<p><br>but you seem to be saying you have too little experience with Wograms
work and modal analysis (haveing done just one yourself) to state this
position as a fact...
<p>You said....
<br>
<blockquote>"Well, as I've said, I have limited experience with the technique.
But that
<br>was on a new grand piano I had designed and built. So I was at least
<br>intimately familiar with the instrument and with what the designer
intended
<br>to achieve with the design. I learned more about the design during
the few
<br>days I was able to work with an engineer from B&K on the modal
analysis
<br>project than I ever expected. It gave me insights into the functioning
of
<br>the soundboard I doubt I'd have gotten any other way."</blockquote>
<p><br>Now I dont mean to tick you off or anything Del... I am really just
trying to get straight what your experience base is on this, and why you
seem to feel so strongly that Wograms standpoint on the relationship between
unloaded and loaded conditions is wrong. Couldnt you describe a bit
more about this example you mention above... what you did, how you measured
both before and after and that kind of thing. I would also be very interested
in knowing what kind of things you felt were valuable... you mention some
insights into soundboard functions... what particulars.
<p>Could any of us learn any of these same things by carrying out the sand
experiment ?
<p>--
<br>Richard Brekne
<br>RPT, N.P.T.F.
<br>Bergen, Norway
<br><A HREF="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A>
<br>
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