In the ES2, oscillator 1 is always the carrier, and oscillator 2 the modulator. In other words, oscillator 2 modulates oscillator 1.
The FM Start setting is great for familiarizing yourself with linear frequency modulation (FM) synthesis.
Load the FM Start setting to hear an unmodulated sine sound, generated by oscillator 1. Oscillator 2 is switched on and set to produce a sine oscillation as well, but its level is set to 0: Drag the small square in the uppermost corner of the Triangle to change the settings.
Do the following:
Adjust the intensity of the frequency modulation by slowly moving the wave selector from Sine to FM. You will hear a typical FM spectrum, with the carrier and modulator set to the same frequency.
Alter the modulator frequency (oscillator 2) by adjusting Fine Tune from 0 c to 50 c. You’ll hear a very slow frequency modulation, which can be compared to the effect of an LFO. The frequency modulation, however, takes place in the audio spectrum. It is adjusted in semitone steps by the frequency selector. Check out the entire range from −36 s to +36 s for oscillator 2. You will hear a broad spectrum of FM sounds. Some settings may remind you of classic FM synthesizer sounds.
Select other waveforms for oscillator 2. Sine is the classic, standard FM waveform, but other waveforms lead to interesting results as well, especially the Digiwaves.
You can achieve further interesting results by altering the carrier (oscillator 1) frequency. Check out the entire range, from −36 s to +36 s here, as well. The odd intervals are especially fascinating. Note that the basic pitch changes when you do this.
In the FM Envelope setting, you can control the FM intensity with an envelope, generated by Envelope 2. The modulation target is the range that falls between Sine and FM in the oscillator wave selector. The first Router channel is used for this modulation routing. You can control a wider range by using additional modulation routings, which have been pre-prepared for you. All you need to do is set their values. Because these modulations work without velocity sensitivity, you can set them in the Editor view by moving both the lower and upper fader halves to their topmost positions.
Do the following:
Set the second modulation routing to 1.0. You’ll hear how the modulation now “wanders” through a broader sound range.
Set modulation routings 3 and 4 to a value of 1.0 as well, and listen to the increase in the sound range.
After these drastic augmentations to the modulation range, the sound becomes uneven across the keyboard. In the lower and middle ranges it sounds nice, but in the upper key range the FM intensity appears to be too severe. You can compensate for this effect by modulating the Osc 1 Wave target by keyboard position (kybd) in modulation routings 5 and 6. This results in a keyboard scaling of the FM intensity.
Because the sound range is so vast (due to the four modulations), two modulation routings are required to compensate for this. Set the lower slider halves to their lowest positions. Good keyboard scaling is essential for any FM sound.
The FM Drive setting illustrates how dramatically the character of FM sounds can be altered when you apply Drive and Filter FM. The results are reminiscent of the feedback circuits of classic FM synthesizers.
Do the following:
Check out different Drive and Filter FM settings.
Lower the Cutoff Frequency of Filter 2 to 0. Envelope 2 modulates Filter 2. This modulation routing is already present in the setting.
In the FM Digiwave setting, a Digiwave is used as an FM modulator. This results in bell-like spectra from only two operators. With traditional FM synthesis, this type of timbre could normally be produced only with a larger number of sine oscillators.
To create a fatter, undulating, and atmospheric quality to the sound, the polyphonic Unison mode has been engaged. Filter and amplitude envelopes have been preset to shape the sound.
Do the following:
Check out the variety of Digiwaves as FM modulation sources.
Check out different Analog parameter values.
You can program the most vivid FM sounds when the modulation source morphs between different Digiwaves. The morphing in the FM Digiwave setting is controlled by LFO 2. The tempo of LFO 2, and therefore the morph, depends on the Logic Pro X tempo—here, two bars.
Do the following:
Set LFO 2 to different waveforms. Lag S/H (smooth random), in particular, should be fun.
Check out different FM intensities and oscillator frequencies.
Alter the modulation intensity of the first modulation routing (LFO2 modulates Osc2 Wave) and the LFO 2 rate.
The FM Megafat setting is well-suited for distorted basses and guitar-like sounds. This sound gets rather “rude” in the upper key range. This cannot be compensated for with key scaling, but not every sound has to be “nice” across the entire keyboard range!
Do the following:
Check out extreme detunings by adjusting the Analog parameter.
Check out the Flanger with this sound.
Engage the filter envelope by lowering the Cutoff Frequency of Filter 2 down to 0.
Add some Glide to lead sounds.
As always when it comes to FM, you can dramatically alter the sound by varying the frequencies of the oscillators. Make sure you check out the odd intervals, as well.
If you’re unconcerned with the pitch of your sound, you can get the weirdest spectra out of odd frequency ratios—oscillator intervals.
The FM Out of Tune setting offers a bell-like sound, reminiscent of a ring modulator. It was achieved through a setting of 30 s 0 c, with the modulator set to a value of 0 s 0 c. Sounds like this were commonly used in the electronic music of the eighties and have had a resurgence in popularity in ambient and trance music styles.
You can further develop the sound by applying filtering, envelope modulations, and effects. There is, however, one small problem—the sound is out of tune.
Do the following:
Use oscillator 3 as a reference for the tuning of the FM sound by dragging the pointer in the Triangle.
You’ll notice that the sound is five semitones too high (or seven semitones too low, conversely).
Transpose both oscillators 1 and 2 five semitones (500 ct) lower. Transposing them upward is not practical, as you’d need to select 37 s 0 c for oscillator 1, which has a maximum value of 36 s 0 c.
It’s important to maintain the frequency ratio (interval) between oscillators 1 and 2. This means that oscillator 1 sounds at 25 s O c and oscillator 2 at −5 s 0 c.