Birkett wrote: > >Question for D.S...what do you mean by `more tone' above? > D. Stanwood replied: > I mean more energy. Such as would be indicated by signal strength from a > microphone. This is different from volume which is relative notes played at > different speeds. > > As I mentioned before, as hammer weight approaches zero so must the tone. > The relationship is something I would love to learn about. I'm sure it's > not linear but it's possible that in the ranges that we use in pianos that > is is on a part of the curve that is fairly straight. I'm only shooting > from the hip here. > You described one of the most obvious non-linearities in the piano recently in the letter you passed on to us here...i.e. voicing. The compliance of a hammer striking a string at a low velocity is in the softer (more linear) outer region of the felt. As the velocity increases the hammer hits the string with stiffer compliances...but this compliance also changes throughout the period of contact between the hammer and string. This is a nonlinear relationship. Tonally the difference is that, compared to a soft blow, a faster hammer speed means (as well as louder sound) a brighter sound. The overall tonal energy is increased compared to the softer blow, but the higher harmonics receive more increase than the lower ones. This nonlinear response to hammer velocity is independent of the mass of the hammer...it's a reflection of the nonlinearity of the hammer felt compliance. The matching of voicing to resonance which you referred to in your letter is an intuitive and empirically-based attempt to control the non-linear compliance of the hammer felt....this is why voicing is primarily an art and needs so much experience to do well. Stephen Birkett (Fortepianos) Authentic Reproductions of 18th and 19th Century Pianos Waterloo, Ontario, Canada tel: 519-885-2228 fax: 519-763-4686
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