tapping strings

[Ron Nossaman]

>Hmm...... stricktly speaking the string and gauge under the panel gives
>you information as to whether or not there is crown.... and nothing
>more. I mean you could just as easily have the same readings on two
>pianos... one that was strung, and one that was not. So if thats all you
>have to go on... how can you say anything about downbearing ? Ok... add
>to the picture that you can confirm positve bearing from strings with a
>rocker gauge or something like that... you still dont know how much
>downbearing there is... because you cant know how much the soundboard is
>resisting whatever downward pressure there is.. so you cant figure it
>out whatever angles you measure.  You can do that however when you know
>what the upward pressure is... and of course when its zero.... that
>makes things easy.

String downbearing is the product of tension and bearing angles. The board
is, under all circumstances, exactly resisting the string downbearing force
- exactly. The measured crown of the board, compared to the downbearing
angles, is an indication of how successfully the board is resisting the
string downbearing force. 


Ron N