Nord User Forum

On my NS3 when i choose FM, i get control over the amount of FM and also control over the pitch of the modulator.
I read the user manual of the Wave 2 and noticed that there are more FM algorithms etc. But, when it comes to control i only found something written about using the OSC control for setting the amount of FM, but didn't see anything mentioned about the controlling the pitch of the modulator.
Is there an option to do that? Seems trivial but i'm asking since i didn't see this mentioned in the manual.

I don't have the Wave 2 and am NOT an expert/that much interested in synthesizers, so take what I'll say with a pinch of salt. The only things I know, I have been discovering them since when I got a reface DX (which I love!), and reading stuff online. And what I have noticed so far is that there seems to be a fair amount of confusion and vagueness, on the internet, around how FM works. I am not sure if that's because it is too complex for the layman to grasp, or because there simply is a lot of confusion around something that could be explained more clearly but for some reason isn't. Or it could be a mix of both.

It seems that the very basic, yet theoretical, thing that's unclear is the very two variables FM works with. According to the way I have understood it so far, and nothing else, those variables are:

- FM frequency, which is the speed you basically apply vibrato to a pitch with,
- FM amount, which is actually the range of that vibrato, up and down by the same amount (for linear FM at least).

This is no different than pitch bending a note with the pitch bend stick within a given range, except that our arms can only move as fast as "a few" oscillations per second, which will result in just... well, vibrato. When that bending speed becomes way higher and approaches similar frequencies of the ones of the very note you are pitch-bending, though, "interesting" (or perhaps "unpredictable") results start to appear. You cease to hear, say, Ab-A-A#-A-Ab-A-..., or G-A-B-A-G-A-...; instead you'll hear just A but with a lot of harmonics.

Now, it seems to me that most FM synthesizers do two things:

- They tell you FM "frequency" in various ways, but generally as a ratio between the modulator and the pitch you are FM-ising, for example "twice the frequency", "a quarter the frequency", and the like;

- They DON'T explicitly tell you the range of this super fast vibrato you're applying. Instead, they have sliders (physical or virtual) that let you set the FM "amount". Whether that's going to be in the range of microtones, semitones, tones, octaves, or the universe knows, I have no idea.

The Synth on the NS3 does the first of those things in a way that in my opinion is even more convenient of the traditional "ratio" way, that is, it tells you how many semitones away that frequency will turn out to be from the pitch being FM-ised, which is more handy. But regarding the second thing, you simply have a knob which, once again, doesn't tell you how many semitones you are making that vibrato range expanding to and from.

Now, I don't know the Wave 2, but if we want to use the language I've employed in this post, so far, you are saying that the Wave 2 doesn't have a control for vibrato speed, but only for vibrato range -- albeit we don't still have a clue about how big that would be in semitones.

Is all the above fair? Aren't you sure the "speed" parameter isn't hidden somewhere else under another menu, possibly called in a different way?

EDIT: I am aware that knowing that value, in semitones, wouldn't be useful since the only thing we care of is the final sound. But still, it would be nice to at least know for a fact that that's the parameter being modified, and by how much.

EDIT 2: The fact that the same effect of FM is achievable via Phase shifting, and therefore that this is what's really going on under the hood of a "FM" synthesizer, doesn't in my view change a thing about the need to know exactly how the parameters are being affected.

I think you got it right. Semitone units make sense for LFOs/vibrato when the value of the modulation amplitude is static (i.e. you reach those extreme values in every cycle of the modulation), but not so intuitive for FM synthesis as (most often) it does not use a fixed modulation amplitude, but it is governed by EGs and sometimes a chain of modulators.
These are quite good, perhaps you've seen them:
https://www.soundonsound.com/techniques ... modulation
https://www.soundonsound.com/techniques ... modulation

The Nord FM engines are a nice thing to have, but they are quite simplistic when compared to current FM synths like the MODX/Montage.

zahush76 wrote:I read the user manual of the Wave 2 and noticed that there are more FM algorithms etc. But, when it comes to control i only found something written about using the OSC control for setting the amount of FM, but didn't see anything mentioned about the controlling the pitch of the modulator.

I think the ratio of frequencies is fixed for each algorithm and you can control the amount of modulation (Level in DX speak) via OSC CTRL (Page 21 of the NW2 manual).

Mr_-G- wrote: These are quite good, perhaps you've seen them:
https://www.soundonsound.com/techniques ... modulation
https://www.soundonsound.com/techniques ... modulation.

Thanks. I did run into them but didn't look very thoroughly. Seemed too complex for my level, but I guess it's time to dive in.

This is not the appropriate place to talk FM, I guess, but my main beef with FM so far would be that it isn't so much about it being difficult, but rather it being *unpredictable*, and therefore, of lesser use than something less capable in theory but much more straightforward in practice.

Even the very basic principle FM works by, namely the fact that once the vibrato oscillation speed approaches audible frequencies, we cease to hear vibrato but instead we hear the same note with a higher harmonics content, isn't THAT predictable to me. I mean it took FM to find that out, it wasn't predictable before. Now we kind of accept it for granted. Conversely, if I apply a low pass filter to a wave, I can pretty much anticipate what's going to happen, and I can thus build my sound the way I want it.

With FM, when more complex setups are employed (a chain of modulators), then it seems to me the level of unpredictability goes so high that it becomes a sort of trial and error until you get, almost by chance, the sound you need. And all of this only when using modulators frequencies which are equal to the pitch of the carrier, or an octave or a fifth away. If the frequency ratio is some non round number such as 1,354, then the only results I have been getting are akin to pure noise...

Of course I am exaggerating, but this was to give a layman impression.

To me it is not so much the "unpredictability", but the "unintuitive" nature of the FM oscillator/algorithms. I do not think you are alone, virtually everybody struggles with FM despite that it can generate some incredible sounds.

Yeah, that's probably a language mismatch but I did mean precisely that. So far it seems to me more of a physics/acoustic curiosity than an actually useful mean to create sounds. Nevertheless, I do enjoy trying.