Wider spectrums of upper partials were observed in the Stuart sound when either the fundamental, 2nd or 3rd partials decayed at a slower rate than the Steinway sound. The higher of upper partials was observed in the onset, and/or the after-sound periods of the Stuart sound. At each of the higher notes, C3, C4 & C5, the Stuart sounds with the wider partial spectra were also observed to transfer to the more settled after-sound oscillation earlier than Steinway.
As discussed in chapter 3, tone quality is determined by the intervening characteristics of the upper partials within the composite sound, at particular duration periods of the sounds’ decay. The Stuart piano sounds discussed in this section were observed to be influenced by the interventions of their upper partials, more so than Steinway.
C5v81 MW mic1
Soundboard: The sounds of C5v81, radiating 3metres to mic1, corresponded with the harmonic vibrations in each soundboard. STE: Fnd / STU: 2nd prt./STE: 3rd & 4th & 5th & 6th prts.
Overall at v81, the Steinway soundboard vibrations were 44% greater amplitude than Stuart for the note C5.
Instrument Volume Mic7: STU 96dB , STE 97dB
String Scale: For the note C5, the diameter of the Paulello-Stuart wire is .35mm thicker, the tensile strength of the Paulello/Stuart wire is 138 N/mm² higher. The Paulello-Stuart wire for C5 is 4.5mm longer, and is set at 7kg higher tension. The yield or capacity of the Paulello-Stuart wire is approximately 10% higher than the Roslau-Steinway wire.
C4v81 MW mic1
Soundboard: The Stuart soundboard vibrated higher amplitudes of the Fnd. and 2nd partial frequencies. Overall the Stuart soundboard vibrations for C4v81 were 67% larger than Steinway.
String Scale: The diameter of the Paulello/Stuart wire is .25mm thicker, the tensile strength of the Paulello/Stuart wire is 177 N/mm² higher, the Paulello/Stuart is 1.5mm longer, and is set at 3.5kg higher tension. The yield or capacity of the Roslau/Steinway wire is 3.6% higher than Paulello/Stuart.
Instrument Volume Mic7: STU 96dB , STE 92dB
Soundboard: Stuart soundboard vibrated 67% larger amplitudes. STU: Fnd.& 2nd
