William said: "This may be the way we've been explaining it for eons, but this theory is certainly in question. Read Ron N.'s article in the April 2006 Journal which speaks directly to this. More, I believe it was Ric Brekne who wrote an article some time back which addressed the concept of pitch change due to soundboard crown increasing. When he isolated the one variable of rise and fall of the soundboard, it was pretty quickly apparent that the amount of soundboard rise required to affect a significant pitch change was absurdly large. The math just doesn't support the theory that soundboard rise and fall is responsible for major pitch changes. It is involved to be sure, but is likely not even the major factor. Lot's to chew on, and I apologize in advance if I've referenced the wrong author." William, It's not just the soundboard that swells in a higher moisture situation. The entire piano swells, which puts stress on the plate and the rest of the sound producing body(s). That's the way I tend to envision it. There must have been some experiments done by manufacturers some where? Anyone? Joe Joe Garrett, R.P.T. (Oregon) Captain, Tool Police Squares R I -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100402/64739f30/attachment.htm>
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