10.6

41Logic Pro Instruments
Logic Pro Alchemy spectral element controls
Source components are shown only in advanced view. Click the Advanced button to switch
to advanced view, then click the A/B/C/D button to select the source you want to edit.
The parameters in this section are shown when the Spectral button is active in a source
subpage. Two Logic Pro Alchemy spectral element effects units are available in the lower
half of the spectral parameters shown in the source subpage.
Note: You must first perform a sample import with a spectral analysis or draw in the
Spectral edit window before you can use any of the spectral engine parameters. See Logic
Pro Alchemy Import browser and Logic Pro Alchemy spectral edit window.
Spectral resynthesis analyzes the changing frequency spectrum of a signal and attempts to
recreate these spectral characteristics. In Alchemy, the audible spectrum of a signal is split
into a large number of spectral bins. Energy distribution across these bins is analyzed and
the sound is recreated by filling each spectral bin with the required amount of signal, using
either sine waves or filtered noise. The results are then summed.
Spectral element parameters
• On/off button: Enable or disable the spectral element in the source. This can be useful
when an audio file has been imported using Add+Spec mode and both the additive
and spectral engines are used to recreate different aspects of the sound. Use the on/
off button to disable either section if you need to listen to the additive or spectral
component in isolation.
• Pitch/Noise buttons: Use Pitch to fill spectral bins with sine waves. Use Noise to
fill spectral bins with filtered noise. The chosen audio import mode automatically
changes the state of these buttons, but you are free to change this to meet the sound’s
requirements.
• Spectral import: Enables only the spectral element and sets the mode to pitch.
The spectral bins are filled with sine waves, which is generally the best choice to
recreate the entire original signal. Noise mode can be useful for transforming normal
speech into whispering, for example.
• Add+Spec import: Enables both the additive and the spectral engines. The spectral
engine is used only to recreate noisier aspects of the sound because this is not a
strength of additive resynthesis. In this case, the mode is set to Noise.
• Volume knob: Set the output level of the spectral element within the source. When
multiple elements are used in a source, use this control to set the relative level of the
spectral component.