Sound waves(The behavior of soundboards)

[Ron Nossaman]

>     This  incidence device, although lacking obviously a level of 
>resolution of
>others, is quite useful when used properly.  It clearly shows substantial 
>motion of
>the bridge when the string has been struck and at the same time shows 
>plainly that
>deflecting the string mechanically by applying pressure and causing it to be
>displaced statically, does not have an effect of any similarity to that when 
>the
>string is struck and vibrates harmonically. 

Robin,
You talk of using a device properly and yet attempt to indicate a lack of
vertical displacement with what is essentially a plumb line.


> It should go without saying that a
>device with greater resolution is likely to detect effects at some point 
>which the
>incidence meter does not show.  Sure, but it is the fact that the incidence 
>meter
>does not show a deflection that is even remotely similar, or even one that is
>detectable in most cases, to that produced by the flexing string that is the
>salient point.

A dial indicator, however, will. As I said. 


>     The model you and others uphold suggests that the string should  induce a
>deflection in the bridge/soundboard when it is stretched in a fashion 
>similar to
>that which occurs when the string is at excursion.  

And does, as I have demonstrated. 


>This device, which is by no
>means crude, as you would suggest, shows plainly pronouncedly different 
>effects or
>resulting degrees of motion from the two methods of loading.  

A gas chromatograph or decibel meter, while being anything but crude, most
likely wouldn't detect the movement either. A measuring tool that is
actually intended to measure the motion you are attempting to detect would
be more appropriate. When measuring a motion you hope not to detect, nearly
anything will suffice. 



>Please don't waste the time of both of us by pointing out that this is due 
>to the
>its level of resolution, something I have noted in the previous post on this
>subject.  

If you noted that, then why didn't you note the rest of the post? This has
all been covered.


>  The fact of deflection being indicated by your laser device,
>although pertinent, is not complete because you would have to be able to 
>compare
>the extent of the measured deflection caused by the finger with those 
>deflections
>caused by the vibrating string.

Not deflection - rocking. The dial indicator measured deflection. And no
one said anything was complete. This has been addressed. 


>     If oriented along the axis of the strings as they cross the bridge, the
>incidence meter will show rocking of the bridge;  by orienting it roughly
at 90
>degrees to the strings it indicates a vertical motion.
>Regards, Robin Hufford

No, it doesn't, as I have explained. 

Robin, I have been as patient as I know how to be during this discussion,
but this post has finally convinced me that your concepts of physics,
logic, and mechanical relationships are so far removed from those I grew up
with and continue to live by that any further discussion is pointless. I
give up.  

Go in peace and believe whatever you wish. I've had enough.

Ron N