Avoid sonic artifacts in EVOC 20 PS in Logic Pro for iPad
The tips in this section can help you achieve the best possible vocoder results with EVOC 20 PS. Also see tips on setting level and frequency and enhancing speech intelligibility.
A common problem with vocoder sounds involves sudden signal interruptions—ripping, breaking sounds—and rapidly triggered noises during speech pauses.
The (Sidechain Analyser) Release parameter defines the time it takes for a given synthesis frequency band to decrease in level if the signal level of the respective analysis band decreases abruptly. The sound is smoother when band levels decrease slowly. To achieve this smoother character, use higher Release values in the Sidechain Analyser section. Take care to avoid setting an over-long release time, because this can result in a less distinct, washy sound. Use short Attack values when a fast reaction to incoming signals is required.
If the analysis signal is compressed as recommended, the level of breath, rumble, and background noise rises. These unwanted signals can cause the vocoder bands to open unintentionally. To eliminate these artifacts, use a noise gate before using compression and boosting the treble frequencies. If the analysis signal is gated appropriately, you may be able to reduce the Release value.
When you gate speech and vocals with the Noise Gate plug-in, use Threshold to define the level above which the gate opens, and use Hysteresis to define a lower Threshold level below which the gate closes. The Hysteresis value is relative to the Threshold level.
Unwanted triggering by low or high frequency noise is avoided by the dedicated sidechain filters of the Noise Gate plug-in.
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