David Love scripsit: > I have had an experience on the other end fo the spectrum. I >have a customer with a Hamburg Steinway A (newer one). She wanted the >action heavier so a previous technician put clips on the shanks. Though >she liked the weight, the tone became very unpleasant to her and others who >heard the piano. I suggested we try removing the clips (she had not made >the connection), fortunately an easy thing to do. The tone that she had >loved about the piano returned. A match of hammer weight to the soundboard >assembly (and the relative density of the hammer, perhaps), is clearly >important. Heavier hammers do not always sound better, as I have often >heard stated here. An interesting experiment, for sure, but putting clips on the shanks is not the same thing as simply "increasing hammer mass". The clips will certainly affect the resonsant frequencies of the shanks which may well have been a significant contributor to the tonal change. We don't yet have general relationships which connect shank flexibility to tone, but there's plenty of anecdotal evidence about this, and shank resonances are a proposed mechanism. How to increase mass without altering shank resonance frequencies? You can't because *any* change in mass distribution of the hammer/shank system will influence these. Even adding or removing mass to (from) the hammer core may influence tone by altering the strike mass/string relationship, or by altering the shank/hammer resonances, or both. These are different phenomena. Unfortunately the nature of piano action mechanism makes it impossible to adjust independently only the strike mass/string mass relationship [which is what will be generally understood by "adjust the hammer mass"]. Ah...the complexities of our difficult friend the pianoforte. Stephen -- Dr Stephen Birkett Associate Professor Department of Systems Design Engineering University of Waterloo Waterloo, Ontario Canada N2L 3G1 Davis Building Room 2617 tel: 519-888-4567 Ext. 3792 PianoTech Lab Ext. 7115 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
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