---------------------- multipart/alternative attachment Delwin D Fandrich wrote: > > > ----- Original Message ----- > From: Richard Brekne > To: pianotech@ptg.org > Sent: December 03, 2001 12:04 PM > Subject: Re: Negative bearing (long) > Delwin D Fandrich wrote: > > > > > The understanding of soundboard function has > > moved a bit beyond the purely > > empirical--even beyond 90% empirical--though > > certainly not to the stage of > > pure science either. Still, techniques such as > > modal analysis have enabled > > the study of soundboard function at a level > > not even dreamed of even thirty > > or forty years ago. It is my hope that before > > I pass from the scene that > > this understanding will be still some closer > > to scientific and much less > > reliant on the empirical. > > > > Del > > > 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. > > > 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. > > Pease go back and read what I wrote, to wit: > "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." > > 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. > > Del > 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... I remember the discussion well... tho perhaps the varying opinions from different folks cloudied what I thought you all were saying at the time... I refer you to the other postings I attached. So... how is modal analysis then a valuable tool.... after the fact as it were ? -- Richard Brekne RPT, N.P.T.F. Bergen, Norway mailto:rbrekne@broadpark.no ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/b6/bc/57/b7/attachment.htm ---------------------- multipart/alternative attachment--
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