FAC ??s

[Newton Hunt]

Hi, Jim,

There are likely two reasons.

1.   If you look carefully at a string where is enter the agraffe from
the speaking side you will notice the string is not straight, but has a
rising curve (catanary).  This curve begins to straighten out with time
and tension and changes the point where the string can be flexed by the
energy from the hammer, thus changing your FAC numbers and the
inharmonicity.  The straighter the sting is at the agraffe the better
the termination and the more powerful the tone.  Strings should be
lifted after being pulled to pitch.

2.   With time the impedence of the board changes, first with load and
second by changes of humidity.  fIf you take the FACs from one piano
several times a year as the humidity changes you will notice that the
FACs change as well.

Have a nice Thanksgiving.

	Newton
	nhunt@jagat.com