In the sound of C4v81 mic1 illustrated above in Spectrogram 3.3, the 2nd prt. is audibly clearer in the Stuart piano sound in the first 3s of the audio sample. Generally the sound of the Stuart is brighter in the onset-attack period.
We can say that the attack transient is faster in the Stuart sounds than the Steinway sounds in both the sounds illustrated above, and that it is the onset transient of the 2ndpartial that is the distinctive quality of the Stuart tone. The attack transient is significantly distinctive in the Stuart piano sound. As previously mentioned, it is in the onset time period of the sound where the most distinctive difference in the piano tones occurs. Because of the vertically positioned rest point of the Stuart string 196 the onset sound of the Stuart is very different to the Steinway onset sound, and beckons a detailed study of its attack transients.
A study of the action speed, and the hammer densities, and hammer shank densities in comparison to the modern piano would be interesting. This study has not produced clear evidence of the Stuart keyboard action speed and hammer densities. Hopefully this will be completed in the near future. As Benade’s description below makes clear, the attack of a sound is extremely complex, containing frequencies that do not belong to the periodic musical category of sound.
When one starts to drive a system of springs and masses at any frequency, there is an initial transient which is enormously complicated, since it is made up of the already complex transient motions belonging to each separate mode of oscillation. We therefore have present in the vibrational recipe not only the driving frequency but also the (decaying) complete collection of characteristic frequencies, exactly as in the case of impulsive excitation. Once the [attack] transient has died out, all parts of the system will settle down into a steady oscillation at exactly the driving frequency. 197
Wayne Stuart suggests the correct measure of sustain in piano sound is the measure of duration from the first maximum amplitude peak to the last maximum amplitude peak, before the decay of the sound begins. My efforts in obtaining this value using Pro Tools software did not produce clear results.
The sustain portion of the sound, is the steady state [rate] to which the sound decays after a time determined by the decay parameters.198
A period during which the loudness varies little, called the sustain. 199
A sound that is described as having ‘more sustain’ in this study is a description of a sound that is decaying at a significantly slower rate than the sound it is being compared to. An example of a piano sound with ‘more sustain’ was observed in the sound C5v54 mic1.
196see chapter2.
197 Arthur Benade,Fundamentals of Musical Acoustics, (New York: Dover Publications INC.,1976) ,165.
198 William Sethares, Tuning, Timbre, Spectrum, Scale. (Heidelberg, New YorkSpringer-Verlag,1998), 30.
199 3 Wolfe, J. “Timbre and envelope,”(Accessed 10 April 2015)
