Killer Octave & Pitch Raise

[David Love]

Not sure I understand this, if you drop the soundboard on a perfect
sphere, the high point will always be the same no matter which way you
place it.  

David Love
davidlovepianos@comcast.net 

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Arnold Duin
Sent: Saturday, February 12, 2005 12:43 PM
To: Pianotech
Subject: Re: Killer Octave & Pitch Raise


Hi Richard

Unfortunately I have to tell you there is no K-point although the K
sounds
appealing it is just the highest point on the soundboard and it has
nothing
to do with the choice to use the rib or the compression crowning method.
As
I understand Steingraeber& Sons uses a different method to crown a board
then Mr. Klaus Fenner explains in his book. They both use the
compression
crowned method though.

When you picture a spherical shape and drop a soundboard on top of that
and
let it take on the shape of that sphere then there will be a highest
point
on that board. The highest point will be on different places dependent
on
how you place your board on the sphere, resulting in possible curvature
in
the direction of the long bridge. Mr. Klaus Fenner wanted to shift the
tension (if that is the right word) in the board to the treble side to
get a
better adoptation to the higher frequencies which he called a
asymmetrical-spherical soundboard crown. Steingraeber sound boards (as I
understand) has his highest point more in the middle of the board and
shapes
his rim to accommodate and support the spherical form of the board. (Mr.
Fenner also shapes the rims) which is a different method than Fenners
uses.

Greetings

Arnold

>
> Thats my understanding of things anyways.  Perhaps some of our German 
> reading friends out there can translate a bit of this so called
K-point 
> from Fenners recent book.
>
> Cheers
> RicB
>
>
>
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