[pianotech] Soundboard deflection - Pitch raise

[Ryan Sowers]

Its times like this that I wish PTG had a research and development
department to answer some of these basic questions once and for all!

I would argue (and no, I have no empirical evidence whatsoever so take it
for what its worth:[?]!) that there must be a number of different factors
effecting pitch drop when pianos are pulled up to tension.

When you consider what the teeniest changes to the tuning pin do to pitch,
why wouldn't the teeniest movement in the bridges, plate, pinblock, rim,
etc, have a noticeable effect?

I agree that the theory that the drop is caused by the soundboard being
pressed down is probably mostly a myth. It sounds good, and seems easy to
explain to clients, but I doubt it contributes much.

On Tue, Aug 4, 2009 at 7:20 PM, <PAULREVENKOJONES at aol.com> wrote:

>  My answer was not a suggestion. It was a request for data to support your
> contention.
>
> P
>
>  In a message dated 8/4/2009 7:26:02 P.M. Central Daylight Time,
> davidlovepianos at comcast.net writes:
>
>  Are you suggesting that soundboard deflection is the cause for the
> predictable 25% - 30% loss in the initial pitch correction even when that
> net change is similar whether pianos have no crown and no bearing or quite a
> bit of crown and ample bearing?
>
>
>
> David Love
>
> www.davidlovepianos.com
>
>
>
> *From:* pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] *On
> Behalf Of *PAULREVENKOJONES at aol.com
> *Sent:* Tuesday, August 04, 2009 2:46 PM
> *To:* pianotech at ptg.org
> *Subject:* Re: [pianotech] Soundboard deflection - Pitch raise
>
>
>
> And unproved. David, where's the data?
>
>
>
> P
>
>
>
> In a message dated 8/4/2009 11:45:27 A.M. Central Daylight Time,
> AlliedPianoCraft at hotmail.com writes:
>
>  Interesting.
>
>
>
> Al G
>
>
>
>
>
>  *From:* David Love <davidlovepianos at comcast.net>
>
> *Sent:* Tuesday, August 04, 2009 10:05 AM
>
> *To:* pianotech at ptg.org
>
> *Subject:* Re: [pianotech] Soundboard deflection - Pitch raise
>
>
>
> Not board deflection but plate contraction is the culprit.
>
>
>
> David Love
>
> www.davidlovepianos.com
>
>
>
> *From:* pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] *On
> Behalf Of *Al Guecia/AlliedPianoCraft
> *Sent:* Tuesday, August 04, 2009 4:19 AM
> *To:* Pianotech List
> *Subject:* [pianotech] Soundboard deflection - Pitch raise
>
>
>
> I did 2 pitch raises yesterday (new customers). One was at A-418 and the
> other was A-420 before I started. What I found interesting was the amount of
> board deflection. On one of the pianos (A-418), the first 3 notes (A-0, A#-0
> & B-0, were dead on, (go figure) on my first pass. I raised the pitch to
> 440, (some notes on this piano were 190 cents flat, wow!). On my second pass
> the first 3 notes were about 10 cents flat. I was surprised that the board
> deflected that much. No question here, just an observation I thought I'd
> pass on.
>
>
>
> Al G
>
>
>
>
>
>
>  ------------------------------
>
>
> ------------------------------
>



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