Set the EFM1 tuning ratio in MainStage
The carrier frequency is determined by the played key, and the modulator frequency is typically a multiple of the carrier frequency.
You can tune the modulator and carrier to any of the first 32 harmonics. The tuning relationship, or ratio, between the two significantly changes the base sound of EFM1, and is best set by ear.
You use the Harmonic knobs to set the tuning ratio between the modulator (left) and carrier (right) oscillators.
In general, even tuning ratios between the carrier and modulator tend to sound more harmonic or musical, whereas odd ratios produce more inharmonic overtones—which are great for bell and metallic sounds.
In this respect, you can view the tuning ratio as being somewhat like the waveform selector of an analog synthesizer.
Note: The Harmonic and Fine tune knobs only affect the tuning relationship between the carrier and modulator oscillators. These should not be confused with the global Tune and Fine Tune parameters, which determine the overall tuning of EFM1 (see EFM1 global parameters).
Experiment with basic tuning ratios
In MainStage, do one of the following:
Set the modulator and carrier to the first harmonic—a 1:1 ratio.
A sawtooth-like sound is produced.
Set the modulator to the second harmonic and the carrier to the first harmonic—a 2:1 ratio.
A tone that sounds similar to a square wave is produced.