[CAUT] Sperrhake Harpsichord wire

[Fred Sturm]

On Dec 4, 2009, at 9:46 AM, Ron Nossaman wrote:

> The mass of the larger wire requires more tension to reach pitch,  
> true, and the smaller wire less tension. The misconception inherent  
> here is that tension and break% are the same thing. They aren't. The  
> smaller wire will break at a lower tension than the larger wire. As  
> a result, the smaller, original, and larger wire are all at very  
> nearly the same break% at pitch. This is what the math shows, and  
> this is what empirical testing has indicated. All these strings will  
> break at about the same pitch, on average.


	Have you actually plugged wire gauges into a spread sheet to verify  
this? And what empirical testing have you done? My own empirical  
testing has shown, on harpsichords, that what I have stated is true. I  
have assumed it would be true for pianos.
	Part of my assumption is based on the fact that bridges are curved to  
a scale, and it is not a logarithmic one that doubles lengths for  
every octave. A given string at the same tension should give an octave  
lower at double the length, two octaves lower at 4 times the length,  
etc. Scales foreshorten these distances. Hence, I reason that the  
given size wire would need to be at a lower tension if the octave  
lower length were shorter. Is this not true?
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu