hammer shapes and symmetry

[A440A@aol.com]

Richard writes: 
>> The shape of the hammer does indeed have an affect on tone, tho 
> whether that is experienced as a positive or negative is a bit more 
> difficult a subject to deal with. Steinway specifies a more or less 
> "V'd" egg shape. 

    I have come to believe that the Steinway shape provides for additional 
tonal range.  The shape is formed out of an uncarved felting, so the tip of the 
hammer is basically felt which is "freed" from the underlying mass.  On a 
dense felt, often with hardener soaked into it, this bit of felt is less connected 
to the grain of the hammer felt's bulk and allows a softer tone on pianissimo 
playing, yet doesn't interfere with the harder felt underneath it when the 
force of play goes up. 
    This whole concept may be more applicable to the earlier hammers I find 
on older STeinways.  In spite of being told that hardener has ALWAYS been used, 
I have cut and filed way too many original Steinway hammers from the '20's 
and '30's to believe it.  Many of those old sets don't appear to have had any 
hardener in them, at all.  The felt was also harder in the middle of the hammer 
than what I see today.  If this is so, then the egg-shape allowed a mechanical 
graduation of density that rapidly softened as it approached the strike 
point.  
   It is plausible that the deformation of the hammer under a strong blow 
would flatten out this strike point, so I wonder if the egg-shape allowed the 
more efficient production of the higher partials under soft play?  ie,  if it has 
a small contact area when played softly, there are less higher partials 
cancelled out by the "footprint" on the string, creating a more complex spectrum, 
even though the softness favored the fundamental.  
   On a lacquer soaked hammer, there seems to be little difference in the 
tonal range due to shape.  
Regards,  
Ed Foote RPT 
www.uk-piano.org/edfoote/
www.uk-piano.org/edfoote/well_tempered_piano.html
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