Soundboard stiffness vs. string coupling

[Ron Nossaman]

>-  When you talk about string-to-bridge "coupling", do
>you mean the physical attachment of the string to the
>bridge so that the string doesn't bounce off the
>bridge, or are you thinking of the mechanical coupling
>factor - a mathematical model representing the portion
>of string energy that is coupled off to the soundboard
>via the bridge?  (My use of the word "coupling" refers
>to the second.)

I wasn't aware there was a difference. Clamped is clamped is clamped.


>-  On a piano with vertical hitch pins (like a Baldwin
>Accujust), if we set the downbearing to zero on a
>single hitch pin (but leave all the other strings as
>they were), will there be a significant difference in
>tone compared to the same string when it has its
>factory adjusted downbearing?

It would certainly surprise me. I've tried it and didn't hear anything 
identifiably different, though I've read one report on the list here 
indicating there was a detectable difference. But then I've read a lot of 
stuff here that doesn't connect to anything in my world, so I'd say you 
would have to try it for yourself if you have any hope of making sense of 
it. Incidentally, a little time with a few Accujust equipped Baldwins and a 
bubble gage will have you questioning the definition of "factory adjusted 
downbearing" pretty quickly.

Ron N