Analysis of the sounds recorded in the MW performance space, on the 9th December, 2013, of four notes, C2 65.406Hz, C3 130.81Hz, C4 261.63Hz, and C5 523.25Hz, established four descriptive factors of piano tone which distinguished the sound of the Stuart piano M19 (STU) piano from the sound of the Steinway piano (STE).

1. A slower rate of decay of the fundamental partial frequency.
2. Earlier transition into the after-sound (a-s) oscillation state.
3. Wider harmonic spectrum at the onset of the sound.
4. A more comprehensive tonal projection to 6 metres.

A slowly decaying fundamental frequency, greater amplitudes of the 2nd or 3rd partial, and the transfer to the after-sound oscillation phase within 1s, describes the qualities in piano sound that distinguish the M19(STU) piano from the Steinway STE 574500 piano.

The direction of radiation of each piano sound within the 180° array, was realised by monitoring the SPL levels of each microphone in the array. For each sound, the radiated harmonic characteristics were tested to see if they correspond to the harmonic vibrations produced by the soundboard. In many instances, the Stuart piano was found to produce larger harmonic sound board vibrations, which corresponded to a fuller harmonic spectrum being radiated over a longer distance.

The sound qualities of the Stuart and Steinway are visually presented in spectrograms, which display the SPL levels of the onset attack, and the amplitudes and rates of decay of the individual partial frequencies. The decay curves display and the rate of decay of the composite note. Tonal qualities were consistently observed in the Stuart piano sounds that contained, a larger fundamental, a larger 2nd or 3rd partial , a faster onset rate of decay usually within .5s, and a slower after-sound decay, often in the 2nd phase of oscillation, immediately after the onset period.

The audible characteristics that distinguished the Stuart sound from the Steinway sound, as heard in the recorded sounds were:

1. A more stable sound, with less movement or change of harmonic balance within the sound.
2. A more balanced sustain established in the first .5s of the sound
3. More bass fullness, or sustain of lower frequencies in the lower notes, C2 and C3
4. A more immediate sounding of the SPL peak in the onset, with a more percussive attack.