Although written for the MONTAGE (some five or six years ago) MODX and MODX+ owners may find the following tutorial article useful (link below)… from the series where we took Motif XF Performances programs as sources to learn about the Motion Control Synthesis Engine.

In the linked article below, we deconstruct a Motif XF 3-PART Performance, by analyzing each component Part separately… which allows us to experiment with several different Filter Types in action.

Although there are some minor navigation differences (the MONTAGE’s right front panel does allow direct button access to Mute/Solo and Element Selection) but the MODX and MODX+ users can easily compensate using the screen, and pop-in menus.

MONTAGifying Motif XF: “Creepin’ Worm”

You don’t need to download anything because the individual Single Parts (there are 3 of them in this tutorial) are all Single Part Performances in the Factory set of your instrument.

The tutorial assumes you are recalling the screens and moving the parameters as you read through it, so you can see and hear how various Filters can be used to accomplish goals. As you’ll see it is vital to be able to isolate individual Elements (in the case of these AWM2 components) to really clearly hear/understand the application of Filters when programming.
Remember, in the AWM2 engine each oscillator (Element) has its own Filter.
In the FM-X engine, the completed sound goes through the one assigned Filter (timbre change in classic FM is handled by the relationship of the Modulators output on its associated Carrier). The Filter added post the construction of the FM-X result, allows for a more traditional application of synthesizer timbre change (ie, filter sweeps, etc.).

Enjoy!

Extra Credit
For a deep dive into BPFs see the analysis of the Single Part Performance “Da Thumperz” found in the following MONTAGifying Motif XF tutorial:
MONTAGifying Motif XF: “Neon Girlz”

Thanks @BM for posting those Masterclass tutorials. They demonstrate just how incredibly powerful the MODX/MONTAGE is as a Sound Design Powerhouse, with very professional and wonderful sounding end results.

My perspective (when trawling YouTube or other Forums) is that the "Synth" and "Sound Design" side of the MODX is frequently overlooked in favour of just selecting an "Instrument" or "Instruments" and a "Rhythm/Beat". I notice they're very popular with "Praise and Worship" Keyboardists... who are hard working, hard gigging musicians in the truest sense.

For me, a totally green erstwhile Guitarist, the MODX came along as a "Gateway Keyboard".... excellent price, excellent power and importantly "Fit For Purpose" Quality. I found myself having to learn everything from the ground up, and with so much power under the MODX hood, it was sometimes hard to see the Wood from the Trees. That's why my little Tutorials are extremely pedestrian in nature... primary school level by comparison. I assume there are (or will be) other MODX Users who know literally "nothing" about Synths in General, or the Yamaha Legacy of making Synth's "better" (e.g. I see the Envelope design harks back to the CS80 and has evolved through many Yamaha Synths since).

Using "pre-processed VCO" Element Waveforms is a neat trick of the trade, It helps cut out the legwork of building "ground up" with plain old Saws, Squares etc. Also, there must be 100's, if not 1000's to choose from. I have two "Analogue Synth" Libraries... "Nostalgia" and "Analog Xperience", where as well as the original "Raw" Oscillator loops (from Minimoog, Prophet 5, Jupiter 8, CS80 etc), they also provide hundreds of "Filter Swept" or "Envelope Modulated" Oscillators... pre-formatted... "Cooked, Ready To Eat and Ready to Go". It's a great technique.

The use of Multi-Element, Multi Part and therefore "Multi Filtered" Synth/Sound Design is a massive advantage the MODX has over more traditional Synth builds.

Going through your Masterclass, the use of Multiple Filter Types, with Multiple Envelope Shapes to make the Filter Sweeps "oppose yet compliment" each other is the stroke of a Master Craftsman... as you truly are.

Even though the focus is on Filter's, I took the time to "deconstruct" those Pads, and find the Filter's are just the tip of a particularly glorious Iceberg!!!

Genius ????

Tutorial#7 - Sweeping With Envelopes Part 1

Before proceeding, some incidental items worth mentioning.

Harmonic Density
So far, for consistency, we have concentrated on One "Oscillator" Element.... a Saw Wave on Key C3.

If you play lower notes, C2, C1, C0, and manually sweep the LPF Cutoff, you will find their lower Harmonics are further apart... there is more "travel distance" when spinning the (Cutoff) Encoder Wheel. This makes the lower Harmonics a little more distinct when sweeping the Filter Cutoff, especially with Higher Resonance.... you get the "Croaking Frog" sounds.
Also, you'll notice that higher harmonics, while closer together, and less distinct, get cutoff at a faster rate... leading us to that squishy or "squelchy" sound. This leads us to another factor regarding Filter Sweeps.... Speed. The faster the Cutoff is being changed (modulated) the more pronounced is the sound... in effect a different Timbre "Sensation".

In the last Tutorial we discussed "selecting a range" of Cutoff values to Sweep. We also noticed that the higher range of Cutoff values, seemed to have relatively low impact on the sound, but we were Sweeping slowly. With a little more Resonance and a Faster Sweep, these higher Harmonics can add a lot of colour and vibrancy to Cutoff movement.

Using an Envelope, we can automate the Sweeping to be a lot faster and more precise than we can manage manually with the Encoder Wheel.

Monophonic vs Polyphonic
So far we have also concentrated on a Single "Oscillator" playing just one Note. Add a Second Oscillator, detuned, with maybe a different Waveform, and the Harmonic Spectrum the Filter is slicing through will be different, producing different results.

The same applies if we play polyphonically, i.e. play chords.

Playing two handed Chords leaves us with no spare hand to sweep the Filter. Again Envelopes will help us here.

Yamaha Envelopes vs "ADSR" Envelopes
ADSR stands for Attack, Decay, Sustain & Release, most always found on Subtractive Synths dating back to the 70's. That's only 4 Parameters to set.

Yamaha's "HADDR" Envelopes by comparison are a lot more advanced, and allow for greater design freedom, but they also require the "management" of 10 parameters.

For the purposes of this tutorial, I will show you how to change a Yamaha "HADDR" Envelope into a basic ADSR Envelope, and stay with that format. Down the line you can experiment with the power of the HADDR once you have the basic ADSR tenets under your belt.

Exercise 1 - Set up an ADSR Filter Envelope

Open your Filter INIT Patch.
Edit Part1 Element1 and go to the Filter EG Page.

Set the following values:-
Hold Time = 0
Hold Level = 0
Attack Time = 64
Attack Level = 127
Decay1 Time = 0
Decay1 Level = 127
Decay2 Time = 64
Decay2 Level = 64
Release Time = 64
Release Level = 0

Leave FEG Depth = 0 for now.

ADSR Equivalents
Attack = Attack Time
Decay = Decay2 Time
Sustain = Decay2 Level
Release = Release Time

These are the only 4 Parameters you will need to adjust

ADSR Definitions:-

Attack = The Time it takes for the initial Cutoff Value* to increase to its Maximum Value as defined by the FEG Depth Value.

Decay = The Time it takes for the Maximum Cutoff Value to decrease to the Sustain Level.

Sustain = The Level the Cutoff Value will eventually reach, if the Key is held and not Released. The Sustain Level is defined by the Decay2 Level AND the FEG Depth Value (Decay1 Level × FEG Depth × constant).

Release = The Time it takes for the Cutoff Value to return to the Initial Level from whichever Level it is at when the Key is Released.

*NOTE: The "Initial Level" is whatever the current Cutoff Value is set to in the "Filter Type" Page, e.g. (0 - 255).

Amp EG
For now set
Decay1 = 0
Release = 85

Amp Release = 85 allows any Filter Release values we set, to be heard and not muted by the Amp Envelope when we release a Key.

This basic Amp EG provides an "open window" through which we will hear only Filter Modulations.

STORE THESE SETTINGS to your FILTER INIT Patch.

Run through the Following Exercises and read the summary after each Exercise to confirm your findings.

EXERCISE 2 - Setting FEG Depth

Set Cutoff = 105 = C3 Fundamental.

Set Attack Time = 0

Ex 2a
Play C3 - Hear a Sine Wave (The Fundamental). FEG Depth = 0, the Envelope is NOT changing the Cutoff Value.

Ex 2b
Set FEG Depth = +32

Play and Hold C3 - Hear a Brighter Attack, decaying to a "thick tone" at Sustain Level... which is "thicker" (more Harmonics) than the fundamental Sine Wave.

Play and instantly Release C3 - Hear a Bright Attack, Releasing smoothly to Initial Level.

Ex 2c
Set FEG Depth = +63

Repeat previous steps. Hear a Brighter Attack in all cases.

Note: FEG Depth Value is increasing the "amount" of Modulation the Filter Envelope is exerting on the Cutoff. For higher Depth values the Filter is opening up more.

Ex 2d
Now...
Set Resonance = 60
Set FEG Depth = 0

Play C3 - Hear a Louder Sine Wave

Set FEG Depth = +32

Play and Hold C3 - Note Squelches, then comes to rest on a "Nasal" sounding Harmonic at the Sustain Level.

Play and immediately Release C3 - the Note fully Squelches down to the Fundamental. (The Filter Opens, and Closes back down to initial Level).

Ex 2e
Set FEG Depth = +64

Play and Hold C3 - It seems like the Attack is "Holding" and there is a slight delay before you hear the Filter Sweep come in. This is because the FEG Depth =+63 has "Pinned" the Cutoff Value, either to Max 255, or otherwise, above our C3 Harmonic Spectrum. We need to Reduce FEG Depth.

Reduce FEG Depth to 53.... we can still hear a little Pinning delay.

Reduce FEG Depth to 48... better.

Reduce FEG Depth to 46... best.

We can assume going forward FEG Depth greater than 47 are of no use to us.

Ex 2f
Now with FEG Depth = +46

Play and Hold C3 - The Attack is brighter, the Squelch is more pronounced, but does that "Sustain Level" sound "out of place"?

Change Decay2 Level (Sustain) = +16

Play and Hold C3 - Aaaah... that sounds better!

Notes Regarding Sustain By changing the value of Sustain we "tuned" the Sustain to provide a more "Musical" Cutoff Frequency as the held note reaches the Sustain level. You will find that "Tuning" the Sustain Level is an important aspect of optimising Filter Envelopes, and you'll be doing it a lot (it is basically trial and error using your ears).

Something else to be mindful of, it can sometimes feel like the sound "bumped into" the Sustain Level and got "Stuck". You can either tune the Sustain (as above), turn down the Sustain to Zero, or, you can use Yamaha's Decay1 AND Decay2 to fix the problem. I aim to write some "Appendix Tutorials", including some more advanced HADDR tutorials, once we've got the basic Filter stuff done and dusted.

Hopefully you have now learned how FEG Depth sets the "severity" with which the FEG affects the Cutoff. On other Synths, the FEG Depth is sometimes labelled "Env Amt" (Envelope Amount) because it defines the Amount of Influence the Envelope has.

Exercise 3 - Key Tracking and other Octaves.
As things are, Cutoff/Key = 0%, and you will notice that the Envelope still has an effect on any other Notes you play, but in each case the effect will be slightly different. This is entirely valid, and is often the desired outcome. If you want to be precise, or want to add more colour you have the option of changing the Key Tracking.

Experiment by playing Lower Notes C0, C1 and C2, with and without Key Tracking. With Key Tracking = 100% the Envelopes effect will be more consistent per Note. The same applies for higher Octaves... C4, C5, C6.

For lower (Bass) Octaves, set Sustain (Decay2 Level) to Zero, and try Increasing Decay2 Time (Slowing down the Sweep) to really "Milk" the Sweeping of those lower Harmonics. Remember, increasing Resonance will help pick out the Harmonics.

You can use the Modulation parameter "Time/Key" with Centre Key Select to automatically increase Attack, Decay and Release Times for lower Notes, and shorten for Higher Notes. In addition, you can alter Envelope Times with Velocity using the "Time/Vel" and "Segment" Parameters. Don't underestimate the power of these optional parameters for adding complexity and richness to your Filter Envelope Generated sounds, especially if you are playing polyphonically... Pads and backing Rhythms.

As an added bonus, use a Cross Delay in the Insert Effects to make those Croaking Bass Note Harmonics and Treble Note Squelches bounce around in the L/R Stereo field.