Hello All,
The choice of strike point (location along the string's speaking length where the felt hammer contacts the string), as designed by any given piano manufacturer, is essentially fixed for any given model by the piano manufacturer.
If you were to continuously vary the strike point of any given note, say G2, and listen repeatedly to that G note as the strike point is varied, you will hear a clear change in the degree of relative loudness in the harmonic overtone series. At some strike points on certain strings, the octave harmonic is the most prominent overtone after the fundamental frequency; at other strike points, one may hear a prominent interval of a twelfth (octave plus a fifth) or a nineteenth (two octaves plus a third), or you may hear combinations of these prominent overtones.
When listening to a freshly tuned grand piano, it is common to hear clusters of notes to each possess, say, a prominent overtone sounding an octave + fifth higher than the original tone. Elsewhere along the same piano, you might hear a cluster of notes favoring the two-octave + major third. Sorry to say, too many times, on lesser quality pianos, there seems to be little or no order of the prominent overtones sounding for adjacently played notes.
The reason I vary (slightly randomize) the strike points is to put some "life" into the Pianoteq sound, as you may have heard in my Campanella fxp. Incidentally, as you vary the damper variables, and listen closely, you will also hear various harmonic contents associated with the releases of given notes. Personally, one of the qualities that seems to give too "perfection" (in the negative sense) in many sample libraries is that the overtones and release harmonics are too, too regular and predictable.
Actually, I prefer to only subtly vary the strike points of pianos; in contrast, to the vibes, marimba, glockenspiel, cimbalom, etc., I prefer to widely vary the strike points. This is because human hands are normally striking the vibrating surfaces, rather than mechanical linkages. As such, when sampled vibes are played, they always seem to have the same overtone series -- duh! -- especially when hitting repeated notes. This is a near impossibility in real life, and this quirk in sampled chromatic percussion instruments ... tends to make them sound "lifeless" to me, as compared to the real instruments, or Pianoteq instruments with highly variable strike points.
Cheers,
Joe
