It seems to me, that if you have a grand in the shop, put a jack under the soundboard and just jack it up 1mm at a time and measure the pitch change. That would, at least, be a starting point of consideration, I should think. Change the humidity in your shop 10% see how much the soundboard will move. A piano will react very quickly to an increase in humidity, but will purge that humidity very slowly. (an article in Scientific American, 1970's proved all of this phenomenon). Those two quick experiments should tell us wether or not the soundboard swelling will change the pitch markedly. Of course, that is only one faction in the whole equation of pitch changing, due to atmospheric conditions, but it's a start. I'm really suprised that studies were not done and documented by some manufacturers. With all the Soundboard experiments that were, supposedly done, by Baldwin, there must be some documentaion laying around somewhere.?????? 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/20100405/667c79c7/attachment.htm>
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