Chaning Inharmonicity

Newton Hunt nhunt@optonline.net
Tue, 30 Oct 2001 15:12:34 -0500


Hi RIchard,

The SAT measures the difference between, in cents, the 4th and 8th
partial on F3, the 2nd and 4th partial on A4 and the 1st and 2nd
partials of C6.

An optimum set of values would be a straight line, like 8, 7 and 6 or
7,7,7 or some such.  I like to see a straight line but C6 no higher than
5 but that is rare.  Now one "D" I had was 7,6,5, real nice numbers but
it rose to 8,9.5,6 and it didn't tune quite as nicely as the previous
numbers.  This piano was used three our four times during a week during
recital season, the ends of semesters.  Those CAUTs know what I mean.  I
also had a concert hall piano I might tune three or four times a week,
regularly, except during July and August.  Same situation.  THese pianos
did end up getting master tunings stored in the SAT for repeat tunings.

DOes that make sense to you?

Regards,

		Newton

Richard Brekne wrote:
> 
> Newton Hunt wrote:
> 
> > Hi Richard,
> >
> > I have seen the "A" of FACs change from 6 to 9.5 one one of my "D"s.
> > That is significant in terms of the end result of the tuning.  OCtaves
> > are a little over stretched for my sense.  SO yes, the change is
> > significant to upset my tuning values.
> 
> I guess I am not familiar with the SAT enough... what exactly the FACs
> say....perhaps you can answer my query this way. Oversimplified... take the
> first three partials... (fund, oct, oct+5) and say the relationship in
> winter is 2.1 to 1 and 3.2 to 1. Is this basic relationship going to change
> with a climate change going into summer ?? and if so does it do so
> proportionally or not. Another words could the 3rd partial relative to the
> fundemental change while the 2nd to the fundemental remain unchanged... or
> something of that sort ?                Newton
> 
> --
> Richard Brekne
> RPT, N.P.T.F.
> Bergen, Norway
> mailto:rbrekne@broadpark.no


This PTG archive page provided courtesy of Moy Piano Service, LLC