MH BB Pinblock

[A440A at aol.com]

David writes:

<<  Do you think that attaching the entire
length of the block itself to the stretcher adds any significant resistance
to vertical movement? >>

  Yes, I do. 
  I think there is some acoustical loss in an unattached block, simply 
because there is vertical movement in it that is not as well resisted by the mass of 
the case.  The difference in stiffness between a block that is doweled in and 
one that is not is profound.  The sound transmission is also noticeably 
different if you tap the undowelled block then clamp it to the stretcher and tap it 
again.  The plate does add rigidity, but adds little  to acoustically connect 
the pinblock with the case. 
    The difference is that in a dowelled block, a larger complement of 
vibration  passes through the block to the stretcher to the case, to the soundboard 
ribs to the dowels to the bridge to the string. That signal path is what I 
consider the "circle of sound".  Mass affects the sound, so anything we do to 
change the mass in the signal path has some effect.  In the undowelled block, a 
larger percentage of the vertical component of the strings' vibration is lost 
to heat dissipation.  Whether it is significant or not is, for 
obsessive/compulsives like me, a moot point.  
       As tuners, (usually with obtuse obsessions to arcane minutia), 
"significant" can have a wide range of definition. I am most comfortable with knowing 
I have done all I can to maintain the structural integrity of a piano, and 
attaching the block to the stretcher, if designed that way, is, imho, 
structurally significant.    
regards, 


Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html
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