Unison Flatter than each Individual string?

[Tom Servinsky]

----- Original Message -----
From: "David Ilvedson" <ilvey@sbcglobal.net>
To: <pianotech@ptg.org>
Sent: Thursday, August 22, 2002 1:12 AM
Subject: Re: Unison Flatter than each Individual string?

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> >>Is this not archaic?  With a ETD you tune the note until the
> >>lights/pattern stops and you have and absolute A440 or whatever pitch
you
> >>want in a few moments.  Is this ETD tuned note any less of a tuned
> >>note?  I got to feel there's a lot of ego involved in tuning aurally
with
> >>a tuning fork...that and masochism...
> >>
> >>David I.
>
David,
You need do some exploring and begin comparing results.
Take (say) A4 and measure all three strings. I use the Accutuner and  will
set it to the 2nd partial A5 and take a reading on the left, center, and
right string.  What will astonish you is that the readings might be
something like..
7.2 for the right
7.4 for the center
6.9 for the left
The reality is that even when we "think" the notes are perfectly in tuned
with each other they actually exhibit differences in partial readings which
will ultimately effect your octave tuning.
So take those readings and add them together (21.5  and divide by 3 and you
get 7.16. Taking the average of those notes will and does affect your
overall outcome. That's why in the earlier days of Accutuner development Al
Sanderson, and I think our own Professor Jim Coleman, Sr, advocated taking
the average of those 3 strings to enter into the FAC equation and not single
string readings. Mind you , we're nit-picking and splitting hairs, but the
differences are obvious. Now that's the computer world trying to make sense
of pitch.
In the aural world we too can exhibit the law of averages by tuning all 3
unisons and essentially arrive at the same point.
Tom Servinsky, RPT