Maximum tension

[Richard Moody]

----- Original Message -----
From: Newton Hunt <nhunt@jagat.com>
To: <pianotech@ptg.org>
Sent: Thursday, June 08, 2000 8:23 AM
Subject: Re: Maximum tension


> The discussion now is about wound strings in the middle
> section.  Ric is correct, wire size is important here BUT
> the real problem is excessive tension because of too large a
> wrap.  Also inharmonicity is extremely high.
>
> So rescaling is essential for durability.
>
> Newton

Which may explain Everett's thinking in using aluminum wrap in these
"cross-over" strings.  Anyhow fwiw, the inharmonity formula predicts that Ih
is less as tension goes up.
    Don't ask me why,  its just a hunch,  but I  think a string would
exhibit less inharmonicity at its "optimum elasticity level."  Since piano
wire is elastic there must be an "ideal  tension."   As the tension goes up
it approaches the elasticity limit, and the dogma dictates you don't want to
go over that. However the  elasticity limit is well below the breaking
point, and some pianos might have strings over the elasticity limit.
    Two low of tension the string doesn't sound right.  Too high tension, it
breaks before too long.  What is the happy medium?   The tone has to be
pleasing and the harmonics close.  Nothing is more fustrating than an
octave  whose second and first partials are in tune, but the fourth and
second beat.   I have a piano with such a problem and am hoping a cam-corder
will record these tuning difficulties. Because if you heard it right after
it was tuned
you would say, "Hey, that tuner needs a machine". Like wise if it were tuned
by machine I am sure the same comments would occur upon aural
checks.  This piano was re-scaled, (by your's truly) but sounds like it
needs to be rescaled again. It could have been the bass string order got
messed up but without the old strings (I had those copied, I did not rescale
them)  I don't know how I would ever figure that one out.   ---ric