Sound waves(The behavior of soundboards)

[Ron Nossaman]

>Problem 2:
>
>a)  I take a small tack hammer and tap the bridge lightly but firmly 
>on its top.  I then give a similar tap with the hammer on the side of 
>the bridge.  The difference in the sound produced is very markedly 
>different in the two cases.  It needs no trained ear to tell them 
>apart.
>
>b)  I take a tuning fork or small tone generator and apply it first 
>to the top of the bridge and then to the side of the bridge.  The 
>sound emitted from the soundboard is the same in both cases.

Let me see if I have this straight. You want me to diagnose what happens in
the bridge before the soundboard moves enough to make the noise by which
I'm to judge what happens in the bridge before the soundboard moves? Isn't
that basically the problem with this discussion? This isn't even
conceptually possible, much less arguable. What you need is
instrumentation. A few accelerometers on the bridge on various planes, next
to a string, and a few on the soundboard. All of them wired to the
appropriate millisecond timing device. Hit the string with a hammer and
look at the accelerometer data to see which moves first - the bridge or the
soundboard. If the soundboard moves first, you win. I'm backing the bridge.
 


>Problem 3:
>
>Why can't I use the tack hammer to drive in tuning pins.  Why does it 
>just bounce off the punch and fly up to the ceiling?
>
>Answer me those.
>
>JD

And this has what to do with bridges and soundboards? 

Ron N