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FM-X Tutorial on complex patches

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Michele
Posts: 0
Topic starter
 

Before buying Montage, I spent several hours reading (and studying in advance) the in-deep articles about Super Knob. I concentrated my attention a little more on FM-X ones, because AWM2 synthesis engine is somewhat well known, coming from Motif XF, Motif ES rack and S90ES.
Although those 4 articles on FM-WX were interesting, my expectation was a bit disappointed because I thought the examples would have been a little more complex.

I see that to understand FM-X one needs to start from scratch, thus simple 2 Operator stacks are fundamental to keep things simple, but since I had DX7mkI (1984, not yesterday) I wasn't able to find an in-deep explanation on how to program a FM complex sound.
I hope in the next coming articles this will be a subject to face.

 
Posted : 08/09/2017 2:55 pm
Bad Mister
Posts: 12303
 

The sounds made by the two Operator stacks are "complex", that was the (perhaps missed) purpose of the series - to show how to make more complex waves from a simple stack, and to do it with an absolute minimum of mathematics; to do it using your ears to introduce the real time controls.

Now perhaps by "a little more complex" you are referring to involving more Operators, or more involved interactions. We purposefully did not do that because everyone is already convinced FM is too hard (it's not) but we wanted to give people a quick look at FM in "Motion" ... what you didn't do on your original DX7 was manipulate the sound manually, in real time (beyond the "usual suspects: vibrato, portamento, Aftertouch, pitch bend)... you certainly weren't adjusting envelopes, tuning Modulators, sweeping Feedback, creating wild resonances, etc., etc. or perhaps you don't remember... mostly you recalled a sound and used the keys as On/Off switches. Now you can interact with the sound in a very organic fashion, by assigning parameters to the AsgnKnob system. This is all new and gives FM synthesis a new and expanded role.

When I found the "Moving Floor" Performance (I'm pretty sure programmed by Peter Krischker) I was immediately drawn to its complexity and its simplicity. I think it shows off what is new, real time and exciting about FM-X. When you think about the four 2-Op FM-X Parts that make up that six Part Performance, they could be contained in just one (8 Op) FM-X Part, but by breaking them open so that each 2-Op stack occupied a Part, instead, it is like a microcosm of MONTAGE.

The advantage of addressing musical components with the entire power of a Part on its own channel are in full effect. I can morph envelopes independently, each with its own changes, I can assign detailed interactive Insert Effects to different components, it's truly multi-dimensional. I was looking for single Operator examples but starting with two is a pretty cool place to start because, if you knew DX7 style FM, you can immediately see/hear that complexity is far greater now. You had to use two Operators basically to move beyond a Sine Wave. Besides it's the interaction between Operators that causes the real magic in FM tone shaping.

To modulate a sawtooth with a sawtooth in the original DX7 FM would require three or four Operators, minimum... in FM-X a single Operator can create a sawtooth, and it can modulate itself!

But to answer your request, a much deeper look into FM-X will be provided with a new series of articles by one of the world's best programmers; I understand it is currently in the works. Standby... in the meantime, how many programs did you fashion starting from just one of those 2-Op Performances? Everything from metallic to wooden tones could be fashioned from just using the 8 AsgnKnob parameter settings and your ears.

Try expanding from there. Teach yourself to copy Operators, and add new Modulators and Carriers to those examples as starting points. The principles are going to be the same... let us hear what you've done... .X7B MONTAGE CONNECT files can be zipped and attached to your post.

 
Posted : 08/09/2017 4:57 pm
Posts: 159
Estimable Member
 

Im enjoying the latest release and using some of these samples and new shortcuts to see if I can get a handle on the simple stuff... then I will try to backwards engineer some of the patches...., as the engineers are pretty tricky it seems.....,

I am using the basic square wave and sawtooth ... (based on being as Ol Arp Odyssey User), and I will be looking to find how to adjust the pulse width of the square wave by LFO and ADSR and control the depth via slider. On another say the sawtooth use a freq resonance, maybe the Ring Modulator 🙂 ...... on a few other sliders... and then have the super knob control the depth, resonance, freq... etc.....

I am thinking that with the latest menu options I should be able to do this as weekend assignment.... Not sure what parameter would be like pulse width on a square wave.... so a lil help on that might be a kick start 🙂

 
Posted : 08/09/2017 6:04 pm
Bad Mister
Posts: 12303
 

Kick start:
If you are looking for a parameter called "Pulse Width" you're barking at the wrong tree... that is an analog synth terminology... so to translate to FM-X you would want to change the harmonic content of the resulting tone. PWM is changing the amount of time the waveform remains making sound with the time it spends silent. In a square wave the positive/negative throw is exactly 50% On and 50% Off... the sound is described as hollow, woody; at an On/Off balance of 10% On and 90% Off... the resulting sound is nasal and pinched. An LFO can be used on analog synths to vary the wave from broad to narrow. You can vary the cycle of sawtooths as well...
this cycling On/Off is happening 440 times in an A440... the undulating/warbling sound is due to the change between a long On/Off ratio to a short On/Off.

In analog world, you built your strings and your brass sounds with PWM - I used to do this experiment in my audio engineering course to show how these two sounds (Wave shapes) are harmonically similar... we would edit tape so that we had a long held chord by a string section, and a long held chord by a brass section... by editing off the attack and the end portion, we would simply have leader tape up to the chord and before the fade - this way we don't get to hear it start or exit... this was to illustrate exactly how important it is to hear the attack and release ... because we use it to help identify instrument sounds. Without the attack portion, it can be very difficult to distinguish strings from brass. Half the people identified the brass as strings....

Call up the FM-X Performance: "FM PWM Pad"
You can learn about two methods of creating a PWM type tone.
There are three stacks: a 2-Op stack, and two 3-Op stacks.
1:2
3:4:5
6:7:8

Carriers are Operators 2, 5 and 8

Just for reference sake, listen to these AWM2 Performances:
Press [CATEGORY SEARCH] repeatedly to select Bank = Preset
Type in "PWM"
Play through these examples (sampled though they are..) it good to get a reference as these are recordings of analog synths...

"Slow PWM Brass"
"PWM Simple"
"PWM Lead"
Etc..

These represent a good array of your classic PWM use... there is a brass, bass, lead, strings... fashioned from PWM Waveforms in the Preset Waveform library.

Compare the Waveforms used in the AWM2 Parts.
In the Waveform named "PWM Fast" you can clearly hear the fast warble - as the pitch width varies over time you hear a distinct warbling in the sound.
In the Waveform "PWM Slow" you can 'feel' the slow warble...

Samples are like photos, they are a slice of time... the "behavior" of samples will be different from an analog Synth doing pwm.

In FM-X, not being a static recording, you can even vary the speed and/or depth of the warble... in several ways (I might add). It still is not the same as a voltage Synth, but this is how you emulate that tone and behavior...

In the "FM PWM Pad" - it is three Parts, if you isolate M:C stack 1:2, of Part 1, for example, you see how a Fixed Frequency Modulator is used to create the warble. It is happening at 2.3161Hz... a little less than 2 and a half times a second. As you learned in the FM-X tutorials, raise/lower the Output level of the Mod Op1 to increase/decrease the warble. You can adjust the Coarse and Fine tuning of Op1 to increase/decrease the speed.

The M:M:C stacks 3:4:5 and 6:7:8 are fairly identical, each has a Sine Carrier (5 and 8) modulated by broad sawtooth (All 1) with a wide Skirt (Operator 4 and 7) tuned at twice Frequency of the Carrier. If you isolate just 4:5 (M:C) it sounds very Square. But add Op 3... 3:4:5 - a Sine tuned to the Fundamental... And you hear the nasal buzz of a narrower wave. Each Operator is detuned slightly to add to the movement within the sound. This internal movement is what make PWM interesting to the ear.

The high notes of this "FM PWM Pad" are convincing as a string-type Pad... most people would not know specifically that it is FM... It's "synthy" to be sure, but great for a true "blindfold test".

There is an LFO (2nd LFO) assigned to create Pitch and Amplitude movement in the result. The Depth is controllable (you set a Depth per Op) and is used to create the very delicate movement in the resulting Waveform.

Notice how the MW is used to 'mix' Element Levels, adjust (by removing) Detune, and lowers the amount of pitch modulation.

 
Posted : 08/09/2017 7:37 pm
Posts: 159
Estimable Member
 

Just wow!... thanks so much for the primer... this is a kick and a 1/2..... , Just awesome content to play with and learn how these sounds are created / emulated. Really appreciated.

 
Posted : 08/09/2017 10:11 pm
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