The resulting algorithm is chosen as follows:
Monophonic for monophonic audio material—bass line, for example
Slicing for percussive, non-tonal audio material—drums, for example
Polyphonic for chords, or complex material—mixes, for example
In Logic Pro, choose Flex Time - Slicing from the Flex Mode pop-up menu.
Slicing cuts the audio material at 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 non-percussive tonal material, such as bowed strings or wind instruments.
In Logic Pro, choose Flex Time - Polyphonic from the Flex Mode pop-up menu.
Polyphonic time stretches material based on a process called phase vocoding—a process that uses phase information to time stretch an audio signal without touching its pitch. It is the most processor intensive of all the flex algorithms, but it delivers high sonic quality with suitable polyphonic material. It’s recommended for complex polyphonic material and is good for all kinds of chords—such as guitar, piano, and choir—and also complex mixes. Polyphonic comes with a single parameter:
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