Sound waves(The behavior of soundboards)

[Delwin D Fandrich]

----- Original Message -----
From: "John Delacour" <JD@Pianomaker.co.uk>
To: <pianotech@ptg.org>
Sent: December 20, 2001 12:21 AM
Subject: Re: Sound waves(The behavior of soundboards)


> At 10:35 PM -0600 12/19/01, Ron Nossaman wrote:
> >Sorry John, but I have one more question I forgot to add to that last
post.
> >
> >When these compression waves supposedly travel down through the bridge to
> >the soundboard, moving the board before the bridge moves, how does this
> >manage to happen with the board attached to the bridge at exactly the
spot
> >that these waves are supposed to move the board? I'd love to know the
> >mechanics behind this.
>
> For the same reason that the wine glass does not shatter the moment
> the lady sings the top C but a moment afterwards.  The glass is
> unaffected while the wave is travelling towards it.  Surely this is
> obvious.
>
> JD


When an object is set to vibrating sympathetically--as with the wine glass
exposed to an adequate amount of sound energy at the proper frequency--it
takes some period of time for those vibrations to build up. It is not
instantaneous.

Del