Sound waves(The behavior of soundboards)

[Delwin D Fandrich]

----- Original Message -----
From: "John Delacour" <JD@Pianomaker.co.uk>
To: <pianotech@ptg.org>
Sent: December 18, 2001 10:56 AM
Subject: Re: Sound waves(The behavior of soundboards)


> At 8:00 AM -0600 12/18/01, Ron Nossaman wrote:
>
> >So you never said the bridge didn't move. Quite true, you didn't. You
said
> >it didn't have to move to make quite satisfactory piano sounds,
>
> I said that the sound was impaired.  You said that the sound ought to
> be completely killed, as it would be according to your theory.
>
> >  but aren't interested in  actually trying it to prove your
> >intuition - even to
> >yourself. Meanwhile, the unchallenged fact that the bridge does move has
> >little or nothing to do with sound production, but it's definitely not
the
> >string movement that is moving the bridge.
>
> What I have suggested all along is that the vibrations travel from
> the string thtough the bridge to the soundboard.  The soundboard
> responds with vibrations in the vertical plane and that it is these
> movements that cause the bridge to move up andf down.  That is the
> whole tenor of my proposition, which neither you no Del seem to have
> noticed.  Your proposition is the soundboard moves because the bridge
> is moved.


Oh, I understand what you're saying. I just don't agree with it.

Are you familiar with the Baldwin electronic SD-6 of the 1950's or 60's? The
piano had no soundboard but it did have a conventional (production) plate,
string set and bridge configuration. The bridges were mounted on a series of
force sensors uniformily spaced under the bridges. Sound was created by
amplifying the electrical signal generated by the force sensors in response
to the motion of the bridge in response to the vibrating energy of the
strings.

Del