Sound waves(The behavior of soundboards)

Brian Trout grandrestorations@yahoo.com
Tue, 18 Dec 2001 13:38:21 -0800 (PST)


Forgive my intrusion into this discussion...

--- John Delacour <JD@Pianomaker.co.uk> wrote:
> I now string one note only of my piano with two
> strings, tune them to 
> the same pitch and strike them with a hammer in
> such a way that while 
> one of the strings is tending to move the
> bridge upwards the other is 
> tending to move the bridge downwards.  <snip>
>Under these
> conditions the bridge cannot 
> be moved by the strings, since a body only
> moves in reaction to a 
> force and in these circumstances there is a
> zero force acting on the 
> bridge.

A practical example of whether or not the above
mentioned "phasing" matters is the situation we
see on a routine basis with unlevel strings. 
When the strings of a unison are out of level and
the hammer strikes them at slightly different
times, you have a phasing effect which may not be
terribly dissimilar to what you describe above. 
It is considered by most to be quite undesirable
and even an untrained ear can often hear the
improvment in the tonal characteristics of the
sound produced by strings closer to vibrating in
phase with each other (level).

No offense intended.

Best wishes,

Brian T.


=====
Brian Trout
Grand Restorations
3090 Gause Blvd., #202
Slidell, LA  70461
985-649-2700
GrandRestorations@yahoo.com

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