Michael, Your questions are entirely appropriate. The graphs are my own invention to describe a hypotheses about downbearing. They are not related to any experiments. You are probably right in pointing out the lack of direct measurements of polarized string motions. There is indirect evidence, though, that the strings behaves in the manner I have described. I refer you to The Coupled Motion of Piano Strings by Gabriel Weinreich published in Five Lectures on the Acoustics of the Piano were the string motions are shown to effect the decay of piano tone. In particular pages 74 and 75 where he talks about the relation between string motion and soundboard impedance. I have simply taken Mr. Weinreichs idea and added the concept of downbearing altering the soundboards impedance. I think this is logical and highly likely. By the way there are some graphs there similar to mine. Although my article contains a lot of speculation there is some hard evidence behind it. What I have tried to do is piece together the various clues from the more credible sources available and to show how they may relate to a specific aspect of the piano. I am a piano rebuilder not a scientist so my interest is in finding ways to utilize the existing information to enhance my craftsmanship. I am not interested nor am I equipped to prove some of the more speculative aspects of the subject. For what its worth, and this may be little assurance, I can tell you that much of the theory in the article is in agreement with my own experience in the shop. In particular the aspects related to string motions described in part three. John Hartman RPT
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