10.6

308Logic Pro Instruments
Freeze the input signal
Freezing the input signal lets you capture a particular characteristic of the signal, which is
then imposed as a complex sustained filter shape on the Synthesis section. Here are some
examples of when this could be useful:
• If you are using a spoken word pattern as a source, the Freeze button could capture the
attack or tail phase of an individual word within the pattern—the vowel a, for example.
• People cannot sustain sung notes indefinitely. To compensate for this human limitation,
use the Freeze button. If the synthesis signal needs to be sustained but the analysis
source signal—a vocal part—is not sustained, use the Freeze button to lock the current
formant levels of a sung note, even during gaps in the vocal part, between words in
a vocal phrase. The Freeze parameter can be automated, which may be useful in this
situation.
• In Logic Pro, click the Freeze button to hold, or sustain, the sound spectrum of the
analysis input signal.
Set the number of filter bank bands
• In Logic Pro, drag vertically on the Bands field to set the number of frequency bands
used by the EVOC20PolySynth filter bank.
The greater the number of frequency bands, the more precisely the sound can be
reshaped. As the number of bands is reduced, the source signal frequency range is
divided up into fewer bands, and the resulting sound is formed with less precision by
the synthesis engine. You may find that a good compromise between sonic precision—
allowing incoming signals such as speech and vocals to remain intelligible—and
resource usage is around 10 to 15 bands.