Stringing Braid

[Delwin D Fandrich]

----- Original Message -----
From: <JIMRPT@aol.com>
To: <pianotech@ptg.org>
Sent: May 28, 2003 8:24 AM
Subject: Re: Stringing Braid and the perception of doing it right


> Cy;
>  Back when I was in a particuarly anal retentative phase I tried using
some
> small bean bag type thingees in the shop....(velour filed with sand
actually) I
> used various sizes such as one note,  three note and six note lengths. So
> reducing back length noise was simple and easy to move around.  The
sound, as Ron
> has said was changed and was a tad fuller overall. Worth the effort?? I
am
> ambivalent but remain open minded on the subject..I hope! :-)  String
braid does
> not truly dampen 'all' vibration in the back scale, rather it reduces it
by
> shortening the cycle???....this while still leaving the flexibilty for
the
> board/bridge to work with????
>  If a particular thingee doesn't need braid then it is 'perhaps' better
to
> leave it out......but doing this should be a well considered and
deliberate
> decision.....
> My view.
> Jim Bryant (FL)
> _______________________________________________



Stringing braid dampens (or, rather, prevents) sympathetic vibrations in
individual backscale string segments. When the piano is sounding--i.e. the
primary string segment, or "speaking length," is vibrating--these backscale
string segments are in motion by virtue of being solidly connected to the
moving bridge. Since vibrating piano strings do not vibrate at single, or
fundamental, frequencies but have a multiplicity of partials and motions it
is likely--regardless of the backscale design scheme--that one or more
backscale string segments will be sympathetic with at least one or more
partials of the speaking length. Just like the vibrating speaking length
these backscale lengths can--and do--drive the bridge. Often at an
objectionable level and frequency.

As well, if they are not otherwise controlled they can--will--continue
driving the soundboard well after the dampers have stilled the vibrating
primary string segments.

By preventing the backscale length from freely vibrating these spurious
vibrations and their resultant sounds can easily be eliminated. This does
not mean that the backscale string lengths are not vibrating, however. They
are still tracking the motion of the bridge. They are just not developing
sympathetic vibrations capable of producing extraneous sounds coming from
the soundboard.

Like Ron, I tend to leave the braid out unless it is deemed necessary by
actual performance. Extraneous sounds, damping problems, etc., are
indications that it is necessary. But these do not show up in all pianos
and I don't mind threading the braid in through the bass strings when
necessary.

Del