soundwaves (the behavior of soundboards)

[Ron Koval]

Here goes, jumping in at the middle again!

Robin Hufferd wrote:
Had this been the case then even a relatively light pressure upon the
bridge should immediately reduce the loudness of the sound emanating from 
the soundboard as it does with the flexing part of the fork and a variable 
pressure would introduce variable volumes in the sound.  This is plainly not 
the case. It is the case, however, that pressure upon the stem and base of 
the fork does not eliminate the sound; and this is  precisely what occurs 
when pressure is applied to the bridge.


Just to test the theory, I took out my trusty fork and gave it a listen.  
Next, walked over to the big, heavy bench with the big, heavy vise.  Clamped 
it down good by the "non vibrating" end and struck it again.  Hmmmmm...... 
very quiet this time.  Maybe no matter how tightly you clamp the fork in a 
fleshy, nonrigid finger, you can't hear a difference.  Yet clamped in a much 
more rigid system, there is an obvious difference.  In much the same way, a 
strung piano soudboard/bridge assembly SEEMS to be rigid, yet allows 
periodic motion (tone, as opposed to a hammer rap) to set the structure in 
motion.  Does it take a lot of energy?  Nope, that's why pianos work.


Ron Koval





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