Alchemy spectral element controls in Logic Pro for Mac
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 Alchemy spectral element effects in Logic Pro for Mac 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 Alchemy Import browser in Logic Pro for Mac and Alchemy spectral edit window in Logic Pro for Mac.
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.
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.
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.