<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <body bgcolor="#FFFFFF"> Delwin D Fandrich wrote: <blockquote TYPE=CITE><style></style>   <blockquote dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <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 03, 2001 12:04 PM</div> <div style="FONT: 10pt arial"><b>Subject:</b> Re: Negative bearing (long)</div>  Delwin D Fandrich wrote: <blockquote TYPE="CITE">  <br>The understanding of soundboard function has moved a bit beyond the purely <br>empirical--even beyond 90% empirical--though certainly not to the stage of <br>pure science either. Still, techniques such as modal analysis have enabled <br>the study of soundboard function at a level not even dreamed of even thirty <br>or forty years ago. It is my hope that before I pass from the scene that <br>this understanding will be still some closer to scientific and much less <br>reliant on the empirical. <p>Del</blockquote> <p><br>Been reading and weeding through and find much that is interesting, but this comment caught my eye and I must admit is confusing. I wrote about modal analysis a year and a half back and you came out and said it was basically useless in designing soundboards, since the conditions for measurement are different then the conditions for full strung, and if done full strung well the deed is already done so to speak... further you pointed out then that you meant that there was no reliable way of forcasting said changes. <br>  <p>From the fall of 1999  where we were in a disscussion about impedance matching, and the usefullness of modal analysis came up I submit the following three posts.</blockquote> <div dir="ltr"></div> <p dir="ltr"><font color="#000080"><font size=-1>Pease go back and read what I wrote, to wit:</font></font> <br><font color="#000080"><font size=-1>    "One of the problems I have with most of the testing I have seen on the piano soundboard is that it was done on an unloaded board and is, therefore, largely meaningless."</font></font> <p dir="ltr"><font color="#000080"><font size=-1>There is no rule that states modal analysis cannot be done with good results on a loaded board, complete with strings. It's just more difficult. Tests with unloaded boards are, in my opinion, largely meaningless. It becomes something else when done in a real world setting complete with strings and loading. Again, my experience is some limited. I have only used the technique to analyze one soundboard assembly and it did lead to some considered changes in the ribbing which--again, in my opinion--improved the performance of the piano involved.</font></font> <p dir="ltr"><font color="#000080"><font size=-1>Del</font></font> <br> </blockquote> Yes... I read all that...and I made that very point about doing it on a loaded board as well, and this was also refuted at the time.... the reason being as I stated..... the deed was already done on a loaded board and you couldnt change it... <p>I remember the discussion well... tho perhaps the varying opinions from different folks cloudied what I thought you all were saying at the time... <p>I refer you to the other postings I attached. <p>So... how is modal analysis then a valuable tool.... after the fact as it were ? <br>  <br>  <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>  </body> </html>