Call for scaling spreadsheets

[Richard Moody]

Twas posted.....
""We've all been led to believe that inharmonicity is caused by the
stiffness of the wire; hence if the tension increases, surely the stiffness
increases.""

Piano wire is elastic.  The more you pull it the stiffer it gets? Never the
less you have to go to the math formulas and the physics professors who
write about them.  To quote one, "Also, if f, the fundamental frequency , is
increased by tightening the string, the inharmonicity is decreased."
McFerrin p 44.  
	I have imagined there is a "maximum vibrational efficiency" of a
piano wire. If it is too slack you loose something, if it is too tight you
run into other factors, number one exceeding the elasticity limit, which is
where the wire is stretched so much it will not come back to its original
length when tension is released, but before it is stretched so much it
breaks.  Like a slinky that doesn't coil back right, or a spring that is
obviously stretched because it doesn't come back to its original shape yet
still functions as a spring.      Rm     

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of alan forsyth
Sent: Friday, September 29, 2006 7:50 PM
To: Pianotech List
Subject: Re: Call for scaling spreadsheets

David Love said , "The higher tension scales will have
lower inharmonicity.  "

I have not found this to be true. What I have found is that higher tension
still has higher inharmonicity, but it's the RATE of increase in
inharmonicity that decreases.
We've all been led to believe that inharmonicity is caused by the stiffness
of the wire; hence if the tension increases, surely the stiffness increases.

AF




----- Original Message ----- 
From: "David Love" <davidlovepianos at comcast.net>
To: "'Pianotech List'" <pianotech at ptg.org>
Sent: Friday, September 29, 2006 7:00 PM
Subject: RE: Call for scaling spreadsheets


>I wouldn't think too long about it--unless it's to more clearly define
> terms.  Higher tension scales such as found on concert instruments
> "project"
> much better than low tension scales.  The higher tension scales will have
> lower inharmonicity.  Tuning the upper treble sharp has little to do with
> inharmonicity or projection.  It may, however, help with the top being
> perceived as flat when heard from a distance.
>
> David Love
> davidlovepianos at comcast.net
> www.davidlovepianos.com
>