SAT/Inharmonicity Observation

[Kevin E. Ramsey]

    By the way, call me weird, but I don't like pulling wound strings more
than five cents sharp; ever. A five cent overshoot would equate to the bass
being 25 cents flat. I always count on a twenty percent overshoot on the
bass bridge. Here's how I figure it; say the bass is 18 cents flat. I double
that, gives me 36 cents. Move the decimal point over one place, that give me
plus 3.6 cents for the overshoot. Gets me right in the ball park every time.
On the second pass, I'm doing fine tuning all the way, doesn't matter if
it's a spinet or a grand. I've done so many pitch raises on grands that were
12 cents flat, where I barely had to nudge the pins a little on the second
pass to know it works. Of course, I have my own style of tuning, where I
like to have the 6/3 octaves a little narrow towards the top, and a little
wide at the bottom, so I fudge to make things sound good, with the double
octave not beating very much at all.
    My priorities are: Unisons-1, Octaves-2, Fifths-3, Fourths-4, Thirds-5,
Tenths-6, Seventeenths-7,................ You get the picture. I am NOT ever
going to de-tune a good octave in order to satisfy a 17th.


Kevin E. Ramsey
ramsey@extremezone.com
----- Original Message -----
From: "Kevin E. Ramsey" <ramsey@extremezone.com>
To: <pianotech@ptg.org>
Sent: Saturday, June 02, 2001 7:50 PM
Subject: Re: SAT/Inharmonicity Observation


>     Terry, you remember the discussion we had a week or so ago about the
low
> tension in the lower tenor on the Yamaha GH1? One of the members came back
> with figures that supported my theory of the tenor section tension being
> dropped too low, and the inharmonicity factor was about double what it was
> in the top note of the bass section.
> Therefore, you could safely assume that the inharmonicity would obviously
> change  with that great a change in the overall tension of the string.
>     On an other note; when a piano is that flat (-140c), the first time
> through I will just pull it up to pitch, or maybe a little sharp, and see
> what happens when I tune the unisons. I count on two pitch raises.
Otherwise
> you're pulling individual strings fourty cents sharp for a differential of
> 180 cents between the tuned and un-tuned notes. Scares me!
>    I'm sure that you do things pretty much the same way, let me know. I
just
> said that more for the newbies who may be lurking.
>
>
>
> Kevin E. Ramsey
> ramsey@extremezone.com
> ----- Original Message -----
> From: "Farrell" <mfarrel2@tampabay.rr.com>
> To: <pianotech@ptg.org>
> Sent: Saturday, June 02, 2001 7:32 PM
> Subject: SAT/Inharmonicity Observation
>
>
> > I serviced a 1940 Chickering Studio today. Hadn't been tuned in
decades -
> > very good condition. It was 140 cents flat. I did an FAC calculation
with
> > the strings 140 cents flat. FAC values were 10.5, 11.2, and 8.5. Raised
> the
> > pitch up to A440. Figured maybe I should double check - maybe
> inharmonicity
> > would change. FAC values @ A440 were 8.7, 9.7, and 7.0. All decreased by
> > about 1.5. I would imagine this simply follows some sort of theory,
which
> > obviously I have no knowledge of. Just thought some might be interested.
> > :-)
> >
> > Terry Farrell
> >
> >
>