Sample Alchemy spectral effect controls in Logic Pro for iPad
The parameters in this section are shown when Spectral is selected in a synthesis module. The controls also vary depending on the selected spectral effect.
Tap one of the handles labeled A/B/C/D to select the source you want to edit.
Formant
Formant is an effect that allows you to shape the spectral content of a sound by emphasizing or attenuating specific frequency bands.
Shift knob: Shift the formant filter up or down in semitones. Higher values can make sounds seem brighter or thinner. Lower values can create a darker, thicker character.
Key Track knob: Determine how the formant filter tracks notes on the keyboard. At 100%, filter resonances shift up or down in pitch with the note. Set to lower values to reduce key tracking, which may make some sounds playable over a wider keyboard range.
Size knob: Stretch the formant filter to change the perceived size of the resonant chamber. Use this parameter to alter the size of a guitar body or to make a child’s vocal sample sound like that of a giant, for example. The Size knob works in conjunction with the Center parameter.
Center knob: Set the center frequency for formant stretching (controlled with the Size knob). Resonances below the center frequency are shifted upward as the Size knob value is increased. A corresponding downward shift occurs to resonances above the center frequency.
Note: The Center knob has no effect when the Size knob is set to 100%.
Low/High Cut
Use the Low and High Cut knobs to shape the tonal characteristics of the sound. The Low Cut and High Cut parameters work in conjunction with each other to act as a bandpass filter, where signals that fall within the two cutoff ranges are allowed to pass.
Low Cut knob: Set a cutoff frequency. All signals above this frequency are allowed to pass. Signals below the frequency are cut.
High Cut knob: Set a cutoff frequency. All signals below this frequency are allowed to pass. Signals above the frequency are cut.
Blur
Blur produces a frequency-blurring effect.
Tip: Try a melodic loop with pitch variations to best hear the impact of this effect.
Mix knob: Set the balance between the original signal and the processed sound.
Length knob: Set the time period that frequencies are sustained (blurred over time).
Variance knob: Set the degree of variation for frequency selection (frequencies that are blurred).
Gate knob: Adjust the volume threshold so that only frequency bands louder than the threshold are played back. It’s similar to a noise gate but applied to each band individually.
Cloud
Cloud produces what might best be described as a cloud of frequency grains, resulting in a textured chorus effect.
Tip: Try this effect on vocal samples.
Mix knob: Set the balance between the original signal and the processed sound.
Threshold knob: Set the number of semitones that the affected bands are shifted up.
Attack knob: Set the time it takes for frequencies emphasized by the Threshold setting to fade in.
Simplify knob: Reduce lower amplitude frequencies to enhance prominent frequencies, lessening detail in favor of an increasingly pure tone.
Metallize
Metallize produces classic comb filter–style effects.
Tip: Experiment with drum loops to clearly hear the impact of the controls.
Mix knob: Set the balance between the original signal and the processed sound.
Interval knob: Set the number of semitones that the affected bands are shifted up.
Simplify knob: Reduce the number of effect-generated frequencies, resulting in a simplified sound.
Feedback knob: Set the intensity of the effect. Higher settings emphasize harmonics, creating metallic resonances.
Noise
Use Noise to fill spectral bins with filtered noise. The Low Cut and High Cut parameters work in conjunction to act as a bandpass filter, where signals that fall within the two cutoff ranges are allowed to pass.
Low Cut knob: Set a cutoff frequency. All signals above this frequency are allowed to pass. Signals below the frequency are cut.
High Cut knob: Set a cutoff frequency. All signals below this frequency are allowed to pass. Signals above the frequency are cut.
Download this guide: PDF