Tom Asked: "Question : Tuning a piano where pitch is 2-3 cents flat and a string breaks @ let's say note C-64. Humidity hasn't changed unless profane comments muttered under ones breath is a factor but now three or four notes on either side of the break are a few cents sharp. I thought with less force bearing down on the bridge at that specific point that the bridge rises and increases tension on the adjacent strings. Is this a convenient but incorrect explaination of what is going on here and does this fit somehow into our current discussion?" Tom, First to explain what I think is happening: The plate is under compression from the string tensions. If a string breaks that allows the plate to react in the opposite direction, causing it's neighbors to go sharp. I liken it to two kids pulling a rope in opposite directions and one kid lets go. The other kid moves backwards.<G> The first time I really got this concept was when I was modifying a Yammie GH1. I had tuned the piano to A=440. Then, I proceeded to remove the treble strings that were in the way of my putting tne new hitch pins and wound strings on the piano. Since that GH1 did not have beams the only thing that was holding the tension was the plate. When I removed those strings, A49 went very sharp! Also, the bridge moved upwards at the same time, exacerbating as well. I think the plate has a lot more to do with the piano going out of tune, than we give it credit for. Of course humidity, (or lack thereof), is the major factor, but heat has something to do with it as well. That's my story and I'm stickin' toit!<G> Regards, Joe P.S. Ron N., Admit that there are Low Tension Pianos and there are High Tension pianos AND any calculation of the increase of pitch raise tension will be different from piano to piano.....hence my "plethora" comment. 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/20100403/319f247b/attachment.htm>
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