Manny’s FM-Xpert #5: “Everybody’s Doin’ the Knob-O-Motion”


Manny’s FM-Xpert is a deep dive into the the FM-X engines of the MONTAGE and MODX Music Synthesizers. This five article series is delivered in an accessible and entertaining way and includes MONTAGE content programmed by Manny himself. The other articles in the series are accessible via the links below: Manny FM-Xpert 1: “Acoustic Eccentricities […]

Manny’s FM-Xpert is a deep dive into the the FM-X engines of the MONTAGE and MODX Music Synthesizers. This five article series is delivered in an accessible and entertaining way and includes MONTAGE content programmed by Manny himself. The other articles in the series are accessible via the links below:

Manny FM-Xpert 1: “Acoustic Eccentricities and Stuff”
Manny FM-Xpert 2: “I’m Fixing a Hole Where the Timbre is Thin
Manny FM-Xpert 3: “It’s Just a Phase, Man
Manny FM-Xpert 4: “The Envelopes, Please”


Everybody’s Doin’ the Knob-O-Motion

Download the updated file associated with this article series here! (Manny FMXpert.X7L)

Way back in the first article, I posited a huge advantage that true synthesis has over sampling is that we can create some extremely responsive & playable piano timbres that can be simply manipulated and changed in ways that samples (or physical modeling) cannot. The trade-off is some timbral accuracy in specific emulative sounds like our piano, but hopefully as you’ve heard the sounds in the Performance Library that the Harmonic Component Modeling approach has yielded eminently usable sounds easily recognized as an acoustic piano.

One of the cool features of the MONTAGE is the extensive realtime control available at your fingertips, and in creating our FM-X Piano we can build in the ability to really morph the sound in extreme directions. I showed a tiny taste of this with simple envelope tweaks in the “Bowed Piano” example mentioned in the prior article. In this article I’m going to show some extremes in which the FM-X can be completely mangled and morphed. I know you’ll like it if you give it a chance, now – so come on, come on and do the Knob-O-Motion with me… (apologies to Goffin & King!)

Starting with a basic example, lets again choose the example Performance “MF*HCM Piano Ex1. Press the audition button, and let it play the full 40 seconds. Something cool happens at bar 9 – the Super Knob sweeps clockwise and the sound changes to a nice, bell/chime digital synth. When it’s finished playing, turn off the Audition and note when turning the Super Knob to the full Left (counter clockwise) position we have our normal grand piano sound. As you slowly turn it to the right you’ll hear 8 stepped changes in the timbre. This occurs as the FM-X parameters for certain Operators Modulator Frequency and Level in all eight Parts are mapped to Assignable Knob 1 and then assigned to the Super Knob:

MannyFMX5 1
You’ll notice I’ve set a custom Curve Type for the Op Freq, so that the frequencies stay locked to integer values from 1.00 (the far left value) to 8.00 (the far right value) This mimics what happens when you change the Operator Freq Coarse parameter, keeping the Frequency of the Modulators in whole harmonic relationships. There are also decreases in the Modulator Levels as the frequencies go up to keep the sound from getting to harsh or create aliasing noise.

That was a simple example, now lets look at a more complex one. Select the Performance “MF.HCM Piano Ex2” and press the Audition button – it’s the same Audition pattern as in “Piano Ex1” but hear when the Super Knob sweep starts at bar 9, the effect is very different. Go into edit mode, and mute all the parts except Part 1 and lets take a look:

MannyFMX5 2
Play and move the Super Knob all the way right (clockwise) and back. The difference here is a custom Curve Type for the OP Freq modulation that creates a continuous sweep of frequency in some regions with plateaus, and it then returns back down to a value corresponding to Op. Coarse Freq 2.00. In addition certain Modulators are not being changed — their Operator SW(itch) is set to ‘OFF’. Two things are occurring – first, as we sweep through the continuous region we create non-integer values as in changing the Operator Freq Fine parameter, so you’ll hear the classic FM ‘clang’ tones along the sloped portion of the Curve. The second is we almost ‘return home’ when the Knobs go ‘full right’, leaving some Ops set to a different whole integer Ratio from their original setting, so the timbre is a little more clavinet like. Make sure you watch the companion video below to see and hear this.

Throughout the eight parts, some Ops have this curve, or a variation of it that fully returns to the original Ratio Freq. Others have the Stepped curve as in “MF.HCM Piano Ex1” so there’s a variable mix & match of integer and non-integer harmonic changes as you sweep the knob. In addition Assignable Knob 2 is set to control Envelope parameters, with a “bell” curve so at the “top center” position of the SuperKnob the resulting sound is a slow attack, sustaining FM pad with a long release:

MannyFMX5 3

As you continue go to full right (clockwise) many Operator envelopes return to the starting values, some stay altered. This gives a timbre that sounds like a piano layered with a synthy sitar. Oh, I forgot to mention – both examples also have some changes in the Insert Effect parameters as well

One other thing you can do with MONTAGE is capture and store the Super Knob position, as well as a number of other settings in Scenes to recall at the press of a button. To see an example of how I’ve set this up that highlights the extremes to which we can alter an FM-X synthesized piano, select the Performance “MF.Dalai La’ MoBlaD2”. The Scene 1 “home” sound is a very bright, noisy and over compressed piano sound ala’ The Beatles “Ob La Di, Ob La Da.” . Scene 2 is a cool sitar like synth (move the Mod Wheel up all the way, and watch the Aftertouch pitch bend!). Scene 3 is steel drums, best above C3. Scene 4 played between C2 to C1 is the classic Synclavier FM sound from the “Beat It” intro, and above C4 it’s a useful music box /chime sound. Scene 5 is a nice, metallic, sustaining FM pad, and Scene 6 is a bright, FM harpsichord/kalimba hybrid sound with a long release tail. Six drastically different sounds morphed from our starting piano timbre from the versatility of FM-X modulations ! Again, watch the video to see a demo of these Scenes.

Finally, call up the Performance “MF.HCM PianoArp+Mseq”. This one is structured a little differently, with the FM-X modulations in the normal “home” settings when the Super Knob is at top center. The modulations then change as you go both left and right, using a bipolar Curve Type for Op Freq:

MannyFMX5 4
In the Performance, I’m using the Motion Sequencer to control the SuperKnob for an auto-play interaction with the Arpeggiator:

MannyFMX5 5
I’ve also utilized the Scenes — Scene 1 has the Arpeggiator & Motion Sequence both “ON” together, and Scene 2 has the Arpeggiator without the Motion Sequence. Also, the Scenes 3-7 call up various versions of the clangorous timbres (reviewed in the video below) all with both the Arpeggiator and Motion Sequence “OFF”. Play around with the Super Knob and find a sound you like!

Check out the video below:

So, that’s a wrap! This article has given you a taste of a lot of really cool stuff you can build into FM-X synthesis to transform a convincing emulative sound – a piano – into some wild digital synth timbres and back through easy, front panel control. Now, dig in and apply the concepts in this article series in building your own sounds. I hope you appreciated these articles, found them useful and managed to survive the deep dive into the covered FM-X programming techniques without getting the bends! If you would like to learn more FM Synthesis tips and tricks, check out the prior two article series (with videos) – “Manny’s FM-Xplorations” and “Manny’s Modulation Manifesto” at YamahaSynth.com.

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