Ghosts of impedance past, and yet to come

[Richard Brekne]

Kristinn Leifsson wrote:
> 
> Speaking of better unisons,
> 
> why is it that the right string in a three string unison, is more often
> than not the one with the least false beats?

Does it ??? I used to think so but I am not convinced anymore of this.
Seems like when I really start taking notes and counting which strings do
what it ends up being much more random as to which strings have false
beating.


> And why does one sometimes have to touch up the right string (again more
> often than not) in the last check of the tuning?

Try reversing or changing the order of which side you tune first. You might
find a change in this as well.
> 
> Always wanted to know that.
> 
> Kromeo Iceman
> 
> At 08:19 16.6.2000 -0800, you wrote:
> >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
> > >

-- 
Richard Brekne
Associate PTG, N.P.T.F.
Bergen, Norway