Sound waves(The behavior of soundboards)

[Ron Nossaman]

>Well, it seems to me that if you can show that the the string vibration in
>response to being excited by the hammer, is analagous in this regard to the
>finger pushing down (or pulling up) the unision, then you have made the
>proverbial very big point in your favour. 

Seems right to me, but that has been my position all along, so I'm
obviously biased.


> Dons suggestion of a strobe
>light..... would that do it ?

I'm afraid not. After the system is vibrating, everything is already moving
and you can't tell what moved first. What you need is something
(accelerometers) that will detect upon a hammer striking the string, the
first movement of the bridge, and the first movement of the soundboard, and
a processing unit with millisecond timing to see which moves second, and
third. I hope we can assume that of the three, the string moves first.


>But just saying it does so doesnt quite make it in my book. Nor does
>apealling to some sense of common sense. 

My appeal was to observation, logic, and physics, not a sense of anything
common, intuitive, or otherwise. So since nothing is conclusive, further
discussion is pointless, as I've said, without actual measurement.


> I too am tempted to think along
>these lines, yet the opposition has made a point about unison strings
>counter acting each other in this regard, and further even if one to some
>degree yeilds this point as far as it is in this context drawn, it does not
>automatically qualify this eventuallity as the primary force that drives the
>sound board. 

I don't believe this ever comes up in a piano, but if it were possible, why
wouldn't the internal bridge compression waves cancel too, being exactly
out of phase? Still, simple leverage says the bridge will rock, however
minutely. Some movement is not no movement, as I have managed to ascertain.
Again, if it  isn't logical to everyone, it needs to be directly measured
for verification. No amount of repetitive discussion will change anyone's
minds, as we have all managed to ascertain.


>That would take a full drawn out and qualified balancing of all
>factors involved in producing the movement in the panel that result in
>airborn soundwaves.

We're still stuck at the point of determining which moves first, as we have
been from the first post. Day one. We're not ready for the details of the
entire symphony, if anyone knows them to tell (which I doubt). That's why
it is pointless to precede with these details. Eventually and inevitably,
after tens of thousands of words of maneuvering, someone will drag it back
to this point and proclaim that anything claimed beyond where we now are is
invalid because this was never resolved. Since no one has apparently
learned a single thing from anything that's been written so far, I'd like
to avoid those tens of thousands more wasted words if possible. 

Ron N