Duplex

[Delwin D Fandrich]

----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: November 03, 2001 3:38 PM
Subject: Re: Duplex


> >"activates the duplex around the "trees" of the bridge pins" - nice
> >line Dan. I agree with you that considerable energy gets over to the
> >rear duplex from the speaking length.
>
> This, I can't agree with. There is way too much bridge to string contact
> area from bridge pin to bridge pin for any string vibrational energy to
> make it directly from the speaking length to the rear duplex. Energy from
> the speaking length will move the bridge, moving the soundboard. the
> movement of the soundboard and bridge will then move the rear duplex.

Ah! A voice of reason and understanding. There is no discernable amount of
energy bleeding through the bridge pin offsets and across the top of the
bridge. The bridge/soundboard system moves in response to the vibrating
energy in the strings and, by definition, causes the backscale string
segments to move.


>
> The
> rear duplex segment that responds to any given speaking length partial can
> be, but isn't necessarily, on the same unison as the sounding string, as
is
> the case with the front duplex.

Of course. All of the backscale string segments--at least all of them within
a reasonable distance from the note being played--are affected. Why is this
such a hard concept to grasp? Indeed, it would be pretty hard--if not
impossible--to set up a system in which at least some backscale string
segments were not excited sympathetically during any kind of normal play.

Del