Killer Octave Question - S shape theory

[Delwin D. Fandrich]

----- Original Message -----
From: "Isaac OLEG" <oleg-i@wanadoo.fr>
To: "Pianotech" <pianotech@ptg.org>
Sent: Saturday, April 19, 2003 3:33 AM
Subject: RE: Killer Octave Question - S shape theory


> I repost that as I will have a discussion with a colleague about it.
>
> S shape as took by the soundboard under the bridge in the killer zone
> being seen as a valuable profile from a stability point of view,
> bridge top being shaped in prevision of this set. I believe that one
> can eventually compute or ascertain where the inflexion point will be
> installing under the load.
>
> Reflex ion after having seen that harpsichord builders are supposedly
> wanting this shape to install on their soundboards, for the same
> stability reason (resistance to moisture change)

I shouldn't think the S-shaped soundboard distortion found in many, if not
most, pianos possesing compression-crowned soundboards can be considered a
desirable feature. Or something that would be designed into either the piano
or the harpsichord. It is the natural result of the compression-crowning
technique being used to make an overly large soundboard and then loading
that soundboard along an off-center bridge.

Del