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

[Ryan Sowers]

But doesn't changing the nose bolts also change the stresses on the plate?
Any pitch change could be caused more by that then by the string height
relative to the bridges.



On Sun, Apr 4, 2010 at 12:25 PM, David Love <davidlovepianos at comcast.net>wrote:

>  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.
>
>
>


-- 
Ryan Sowers, RPT
Puget Sound Chapter
Olympia, WA
www.pianova.net
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