Dead Note

[Jim]

Dear list:

When I layed out the soundboard-bridge-rib alignment for the piano which
later became the Walter piano, I was ignorant of the need for a rib
to pass under the portion of the bridge notch under the plate strut.
vibration energy travels down the bridge easier than in spruce.  Where
there is a notch in the bridge the tone gets choked off partly because
there is too much flexiblity and the higher partials are dissipated
rapidly.  This leaves a rather thumpy tone.  No amount of voicing
will cure this.  Try the pluck test, you'll see that the problem is
in the tone generating system.  The Kawai company had the same problem
in their 45" studio.  They alleviated it by placing a beech bar on
the back side of the soundboard between two ribs under the notch area.
Chuck Walter followed course and did the same thing later, solving the
problem of dissipation.  He later redesigned the entire soundboard layout
which greatly improved his piano.  I am not to be credited in any
way with the current Walter pianos.  They are much better.

There is a tendency to lose down-bearing at the bridge notch.  It is
better to not have a bridge notch, but on many vertical and some grands
it is necessary because it it impossible to sufficiently strengthen the
plate in that area and still have bridge clearance.

You can't solve tone generating problems with voicing.  You can only
slightly cover them.

Jim Coleman, Sr.

On Mon, 27 Aug 1956, Bonifield-Poulson wrote:

> List Members: I recently restrung Vose and Sons upright, circa 1900.
> One problem has cropped up.  G5, the first note after the treble plate
> strut, has very little sustain and much less volume than its
> neighboring notes.  I've tried voicing it up, down, and every which
> way, with no improvement.  The bridge at this point is notched quite
> deeply,to pass under the strut, and the strings for G5 are very close
> to the edge of the notching.  Scott Johnson of this list has suggested
> that the energy transmission has been compromised by having the
> strings so close to the edge.  He suggested installing a maple bar on
> the back side of the soundboard, behind the bridge, to increase the
> energy transmission, and also lightening the hammer moulding and
> reshaping the hammer to more of a pointed shape.  Any other ideas
> before I dive in to these modifications?  The owner is  nervous about
> operating on his heirloom instrument.  Thanks, Patrick Poulson, RPT
>
>