[pianotech] Pitch Change (was: Grey market pianos, seasoned pianos, etc.)

[David Love]

It's not hard to do a simple test of bridge height change and accompanying
change in pitch using the nose bolts of a given piano that has them.  By
lowering the plate a measured amount you can effectively calculate a change
in the in the bridge height (using bearing measurements as well) and then
measure the change in pitch.  It's not a perfect test but it can give some
idea.  While I can't comment on Ric B's calculations not having done them I
can say that even modest changes to the nose bolts create quite a difference
in pitch when compared to the normal seasonal change we experience.  I'm not
convinced that the soundboard/bridge rise and fall isn't a significant part
of the pitch change even if it is not the entire story.   Certainly
compression soundboards change enough during seasonal swings as to impact
the tone, that they should impact the pitch would not be unexpected.   For
purposes of client communications and simplicity I think it's not an
unreasonable offering.  

 

David Love

www.davidlovepianos.com

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ryan Sowers
Sent: Saturday, April 03, 2010 10:09 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Pitch Change (was: Grey market pianos, seasoned
pianos, etc.)

 

It sure looks like the sun is going around the earth too, and people had a
hard time wrapping their brains around the fact that the opposite is true. I
really think the rising/falling soundboard theory (RFST?) fits in the same
category. Actually, geocentrism actually makes more sense because the theory
at least seems to fit our direct observation. Nobody really observes the
soundboard rising and falling. Maybe because we know there is supposed to be
crown in a soundboard and the tuning drifts in a crown like pattern in
response to humidity change makes the RFST make sense. 




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