Oops... Re: Unusual rib structure?

[Delwin D Fandrich]

----- Original Message -----
From: "gordon stelter" <lclgcnp@yahoo.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: May 08, 2003 3:40 AM
Subject: Re: Oops... Re: Unusual rib structure?


>
> Why? I can see that with a proper cutoff bar.
> But aren't we really saying the same thing here, with
> a slightly different "angle": that they were trying to
> get sound production out of an otherwise dead portion
> of the board? .
>      T
>
> > The idea is to keep the available energy out of that
> > corner.
> >
> > Del
> >

I'm not sure just what the theory behind these devices was (is?). I've not
found anything in the literature I have available that discusses them at
all. If the theory was to get sound production out of an otherwise dead
portion of the board, it was a flawed theory.

In no case is this a "dead" portion of the board. It moves. Unfortunately,
it moves out of phase to the main speaking portion of the board. The strap
across the ribs does not alter this. It does add a bit of mass and it
certainly adds some stiffness and this is generally helpful. But it is not
as beneficial as a full cutoff bar.

Del