10.6

31Logic Pro Instruments
• F2/FX A/B/C/D: Source output is routed to main filter 2 and effects rack A, B, C, or D.
The balance between these targets is set with the Send knob.
Note: Signals sent to effects rack A, B, C, or D destinations bypass the main filters
when the Send knob is set to the full-right position. See Logic Pro Alchemy effects
overview.
Logic Pro Alchemy source filter use tips
Alchemy provides multiple filter types at different positions in the signal path. You can use
filters at the source level, and the main filters, and you can also insert filters in the effects
section. The positioning can have a significant bearing on the sound produced and can also
impact on the processing resources required. Depending on currently available resources,
you may need to pay close attention to envelope settings, the number of voices, and other
parameters to achieve the sonic result you are chasing.
• Source-level filtering provides the most precision and potentially the greatest sonic
impact on your sound. The downside is that source-level filtering requires more
processing resources. Processing is per voice.
• Use of the main filters is more CPU-efficient and can have significant sonic impact.
Processing is per voice.
• Effects section filters process the entire signal, rather than each voice independently.
Filtering at this stage of the signal path is often used to refine the overall sound or to
provide a performance control variation.
Use an FM filter as a sound source
The FM filter produces a sine wave that is modulated by your source signal. Because the
FM process adds harmonics to the sound, the more complex the sound you feed into the
filter (and the louder it is) the more quickly the sound is distorted. FM in Alchemy is great
for aggressive sounds, but is also useful for basses and other sounds.
Unlike dedicated FM synths, Alchemy does not have preconfigured algorithms or a
modulation matrix set up for FM synthesis. It does, however, offer the option to run a
huge number of “operators” (FM filters) in various series and parallel configurations. FM
in Alchemy also has a sonic character that’s different from classic FM synths. This means
following the approach outlined in the steps below is not always the best option in Alchemy
if you want to recreate classic digital FM sounds. Such sounds are often more easily
achieved by other means, such as with additive synthesis or resynthesis. FM in Alchemy is
more like working with FM on analog synths where you modulate oscillator frequency rather
than phase.
1. In Logic Pro, from the Name bar, click the File button and choose Initialize Preset from
the pop-up menu to reset all Alchemy parameters to default settings.
2. Switch to advanced view, then click the A button to show source A parameters.
3. Use a sine or triangle wave as your source sound.
4. Click the source A filter On button to enable the filter, then choose FM from the Filter
type pop-up menu.
5. Control-click the Frequency knob, and choose Envelope Follower > Source A.