[CAUT] How long to stabilize??

[Fred Sturm]

On Feb 19, 2009, at 9:12 AM, Andrew Anderson wrote:

> Speaking from an observational point of view without carefully  
> measuring; it seems that the opposite swing of the outside unison  
> strings might be related to unequal string lengths between tuning  
> and hitch pins.  Seems to me that this is one of the stated reasons  
> for single string unisons a-la Bosendorfer et al.  Having a little  
> experience with Bosendorfer, I am not certain that this holds up  
> under scrutiny, comparatively. The opposite would then be true of  
> uprights as well and I do note the swing in them, some more then  
> others.

	The biggest and most consistent difference having to do with string  
length is in tuning pin placement. Uprights are the reverse of grands  
(right string tuning pin closest to termination in uprights, farthest  
in grands), yet both uprights and grands move the same way - right  
string moves the most in the dominant direction (flat when dry, sharp  
when wet). So that seems to rule that theory out. In addition to the  
tuning pin pattern of the Steinway D and B and similar, where in  
alternate unisons tuning pins are offset dramatically stepwise - and  
there is no observed difference between adjacent unisons, while there  
_is_ a difference between left and right strings.
	My best guess is it has something or other to do with bridge/ 
soundboard, and is connected in some way to the pattern of bridgepins  
on the bridge - as in notching, and some being closer to the center,  
others closer to the outside. But I can't come up with a model as to  
how.
	In any case, it happens, and it happens pretty consistently within  
model of piano. Why one model/design differs so much from another is  
an additional mystery.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu