Apple Logic Express 9 - Manual (Page 526)

Rhythmic
Rhythmic flex mode time stretches the material, looping audio between slices in order
to fill any gaps. This mode is most suitable for nonmonophonic material, such as rhythmic
guitars, keyboard parts, and Apple Loops.
• Loop Length: Sets the length of the looped section at the end of a slice that is used for
time expansion.
• Decay: Defines a decay value for the looped area.
• Loop Offset: Allows you to move the looped area up to 100 ms to the left, preventing
pre-attack sounds from the following transient to appear in the looped and crossfaded
area.
Monophonic
Monophonic flex mode is designed to be used on melodic instruments only playing a
single note at a time, and is therefore good for solo vocals and monophonic solo
instruments—melody and bass lines, for example. When you use this flex mode, your
recording should be relatively dry, without audible reverberation. Otherwise, you may
want to try using Polyphonic.
Monophonic flex mode comes with a single parameter—percussive—that preserves the
area around transient markers to protect the percussive part of the sound. If selected,
allows better timing for all kinds of percussive monophonic tonal material, such as plucked
strings (guitar, bass) or tonal percussion. If unselected, prevents glitches on transient
markers in nonpercussive tonal material, such as bowed strings or wind instruments.
Polyphonic
Polyphonic flex mode time stretches material based on a process called phase vocoding—a
process which uses phase information to time stretch an audio signal without touching
its pitch. It is the most processor-intensive of all the flex modes, but it delivers high sonic
quality with suitable polyphonic material. It is recommended for complex polyphonic
material and is good for all kinds of chords—such as guitar, piano, and choir—and also
complex mixes.
Polyphonic flex mode comes with a single parameter—complex—that enables more
internal transients in the audio material.
Tempophone
Tempophone flex mode emulates the effect of a historical tape-based time-stretching
device known as a tempophone, and results in a mechanical sound with many artifacts
similar to those produced with granular synthesis techniques. It is intended to be used
creatively for special effects.
• Grain Size: Sets the size of the grains that are played or repeated in their original speed
and crossfaded to create time compression or expansion.
526 Chapter 16 Flex Time Editing