Apple Logic Pro 7 - Manual (Page 406)

406 Chapter 11 Sample Editor
You can move the ball in the 3-dimensional display with the mouse. Naturally, only two
dimensions can be accessed at once; use Shift to switch between two different 2-
dimensional planes (enabling you to reach every point of the 3D graph). Holding
Control, Option, or Command limits ball movement to one axis, allowing independent
timbre, transposition, or length changes.
You can also grab and move the shadows of the ball. These are its projections on the
timbre axis, and the transposition/time plane, respectively
The position of the ball directly effects the numerical values, and vice versa.
You can reset the ball and all numerical values to centered (neutral) positions by simply
double-clicking in the graphic display.
Time Machine—Harmonic Correction
Harmonic Correction
Activating Harmonic Correction alters (corrects) the formants that define the timbre
(sonic character). If On, the formants in the transposed material remain unchanged. This
means that the original timbre (or the physical size of the resonance body) is
maintained, resulting in a more natural sounding transposition. The only trade-off is
that calculation takes more time.
Switching Harmonic Correction to Off shifts the complete spectral structure (including
formants) of a sound, in accordance with the transposition value. This is the “normal”
type of transposition, as seen in other programs, or the pitch shift algorithms of effect
processors. These algorithms are also included in the Time Machine, and can be used
for much faster calculations, or when you want the “effect” of pitch shifted formants.
Harmonic Shift
If Harmonic Correction is activated, you can also use the Harmonic Shift parameter to
independently alter timbre. The units are cents—100 Cents = 1 semitone.
If you select the same value in both Harmonic Shift and Transposition, no correction
occurs, and the result is as if Harmonic Correction is switched Off.
If you set Harmonic Shift to zero, the formants don’t change. This avoids the unwanted
side effects of traditional pitch shift algorithms.
If you set Harmonic Shift to
−
300, for example, and the Transpose value to zero, the
sonic character of the material will be changed as though it was transposed three
semitones down—but without an actual transposition in pitch. This means that a
musical “C” remains a “C”, but the timbre of the sound (a voice, for example) becomes
darker.