Ghosts of impedance past, and yet to come

[Joe & Penny Goss]

Ron,
Interesting! Do you suppose that wire size changes, minute differences of
strike point or shape of the string at the termination point could cause the
different results? That is only a few posibilitys.
I do not know where this statement comes from but " the theory of three,
any three tones sounding together closely in tune will sound in tune."
This is why I choose to tune one string to a target point and the other
strings one at a time to the target string. The results are most of the
time, but not always, a better unison.
Joe Goss
----- Original Message -----
From: Ron Nossaman <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Friday, June 16, 2000 5:52 AM
Subject: Ghosts of impedance past, and yet to come


> Hi Gang,
> Anyone remember my fevered speculations about the possibilities of the
> reported pitch drop from a single string to a two or three string unison
> possibly being related to the soundboard/string impedance match/mismatch?
> Well, it just got stranger.
>
> Tuning the Kimball grand I'm finishing up, I set Tunelab going so I could
> watch what a unison's pitch did as I progressed. I spent most of my time
in
> the top half of the scale. Some unisons dropped slightly, some stayed the
> same, and some climbed in pitch as the second and third strings tuned in.
> It was about an even three way split on probability, with no obvious order
> or grouping as to position in the scale. The changes in the timing of the
> attack pitch climb and drop back to dwell pitch were every bit as erratic
> as the dwell pitch change. Some unisons that hadn't changed as the second
> and third string tuned in, tended to climb slightly in pitch in decay.
Some
> dropped.
>
> Thinking I might have some control of the process by where I centered the
> tuning of that second string, I played with it a bit within that area just
> sharp or flat of dead-on to the first string - where you can wooly up the
> attack a little without leaving a noticeable roll in the unison. Some
> unisons seemed to be slightly steerable, some not. My favorites were the
> unisons that went sharp as the second string tuned in, even when the
second
> string was still a beat low.
>
> In most cases, the addition of the third string took the climbers a little
> higher, the droppers a little lower, and left the non changers non
changed.
> The only reasonably dependable effect I found was that the attack phase
> pitch climb  tended to shorten in duration with the addition of each
> string. It was interesting watching the attack phase of the unisons that
> climbed in pitch. The single string envelope profiled about like that of
> any other single string. Adding the second string, the attack pitch climb
> seemed to be less than with the single string, but rose to maximum dwell
> pitch in a second or so.
>
> So far, no answers, just more and different effects than others are
> reporting. I'll tape off the back scale and play with it some more this
> weekend. That will probably just add another layer of unaccountable
> weirdness, but I might get lucky too.
>
> Later,
> Ron N
>