I have read what has already been written in this thread, currently. Ron, I'm not going to sift through the archives. The dissusion has been and still is being presented now. I'm merely adding to it as you are giving my current thoughts on the matter again, as you are. Have YOU had the time to do all of these measurements yourself? If so, I don't know how you managed to find it let alone have the patience for it. I haven't nor do I have the desire to do so. Taking measurements is not the only proof available. When does logic and common sense ever come into play here? Yes, of course, everything will change from the sound board movements. It's "logical." :-) As I asked, then, what else can it be? If the piano were entirely made of some material that did not flex in any way whatsoever, would the piano strings still change pitch as they do? -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Ron Nossaman Sent: Saturday, April 03, 2010 10:35 AM To: pianotech at ptg.org Subject: Re: [pianotech] Pitch Change (was: Grey market pianos, seasoned pianos, etc.) Gerald Groot wrote: > OK, a little play in words....... In so many sentences you and others are > indeed saying that it is not the main reason. I am saying that I think it > is. Has the rise and fall ever been measured? You mean instead of just taking it on faith? Have you ever calculated the string elongation change necessary to produce the tension change to take a string's pitch 5¢ higher or lower, and how much the soundboard would have to rise or fall to accomplish this at the low to vanishing downbearing angles we find in pianos? How about comparing downbearing readings before and after seasonal pitch swings? If the soundboard's moving enough to make the tensions change that much, the angles will change too. > Doors and door jams expand and contract as much as 1/4" during each seasonal > change. Sound boards do expand and contract a lot. If it is not the > expansion and contraction of the sounding board causing it, then, what is? Read what has already been written in this thread, and chase it down in the archives. There's plenty of discussion. Ron N
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