voicing - was Convention musings

[Delwin D Fandrich]

----- Original Message -----
From: Joe & Penny Goss <imatunr@primenet.com>
To: <pianotech@ptg.org>
Sent: Wednesday, July 28, 1999 4:49 PM
Subject: Re: voicing - was Convention musings


>
> Del,
>  The bass and other strings that have the hammers angled to the string
will
> have a different strike point measurement from the termination points of
> bridge and agraff/capo bar. This causes to my ear the distortion of the
> sound of the unison much like phasing of unlevel strings. As a double bass
> player, I long ago discovered that one could divide the string into 1/2
> 1/3  1/4  segments and play the overtone series ,  but also divide the
> string into smaller segments and draw out a diatonic scale of the upper
> partials of the string. Moving the finger lightly along the string only a
> small fraction of an inch will make the change occur.
> With the string line angled one way and the hammers the other will MHO
> cause what I believe Roger is referring to especially on bass strings that
> are already too short to produce a good sound.
> Joe Goss
> -----------------------------------------

Joe,

I am aware that there will be two different strike points on these strings.
Three actually, if you are working with a tri-chord unison.  (Actually, both
the strings and the hammers are angled in the same direction.  It's just
that the hammers are not usually angled as much as are the strings.)  But,
to keep things in perspective, these variations in strike point are very
slight.  For example, in the scale I worked out for my Journal articles on
the problems of small pianos, the lowest tenor unison (#33) has a speaking
length of 900 mm.  The nominal hammer line is located at 1/8th of the
speaking length (that is, as referenced to the center string of a tri-chord
unison.)  The string is drawn at a 28º angle (from vertical) and the hammer
is at a 14º angle.  This places the design strike point on the left string
113 mm from the V-bar (or 1/7.9646) and on the right string it is 111.2 mm
from the V-bar (or 1/8.0935).  This assumes a perfectly functioning action
with absolutely no deflection, or whip, taking place in the hammershank (or
any of the other action parts) as energy is transferred through it to the
hammer.

While this is a pretty extreme example -- it is, after all, a fairly short
vertical piano where string angles are generally much greater than they
would be in comparable grands -- these differences are still quite small.
As I said in my earlier post, "I've certainly not found it (the phasing due
to hammer angles) to be a major factor piano tone -- at least not with
string lengths typical of bass/tenor crossovers."  To hear and identify any
possible tone differences that result from this slight variation in strike
point will require very careful listening to single notes and concentrating
carefully on analyzing what is being heard.  This is not what I would call a
"major factor" in the tone abnormalities typically found on either side of
the bass/tenor crossover.

The tone variations caused by poorly designed rib scales, poorly placed
bass/tenor crossovers, poorly designed string scales, etc., are not that
subtle.  They are easily heard and identified and they are musically
intrusive.

Regards,

Del