FM synthesis

3DOFan · Post by **3DOFan** » Sat Jun 30, 2012 3:58 pm

Well, I've been trying to understand how to replicate typical FM sounds using the korg r3 and have not been able to figure anything out really. I find it rediculous that nobody seems to understand FM synthesis, and when you ask how to use it, you merely are told "go look at the presets, they might help".

Well, I'm pretty much asking how one would replicate brass(orchestral and synth), acoustic piano and bells.

I've tried using ring/sync with the oscillators, but the harmonics and tuning have been bothering me.

If you would like an example of the types of sounds I'm trying to create:

http://www.synthmania.com/dx7.htm (brass/orchestra)

http://www.youtube.com/watch?v=Pn7DMwPHXLk (piano)

http://www.youtube.com/watch?v=HGxMDxGJXuo(bellls come in at 2:36)

I've gotten a rough approximation of the orchestra brass, but not using all FM, an dwould rather know how to create it using only FM.

And, I know bells are usually simple, but the bells I'm trying to create sound unusual compared to your typical DX bell patch.

I'm not so much requesting the patches be made for me as I am requesting to understand how FM synthesis can be emulated/used on the korg R3 to create such sounds as I have refrenced above.

Thank you.

tpantano · Post by **tpantano** » Sat Jun 30, 2012 6:31 pm

... Ring modulation isn't FM, it's amplitude modulation and frequency mixing. Sync modulation is also not FM; it simply restarts the phase of the sync'd oscillator.

Have you tried actually using something like FM? VPM on oscillator one is the closest thing to true FM on the R3.

Start with a sine wave, experiment with different harmonics and modulation amounts.

Do note that you're not going to get many DX7 style patches with your R3– the DX7 had many operators, whereas VPM on the R3 will only give you one.

3DOFan · Post by **3DOFan** » Sat Jun 30, 2012 7:05 pm

ah, well, what I was doing earlier was using VPM on one oscillator and ring mod/syncing the second oscilator to my first one, I got some interesting sounding brass using this technique with sine waves. But, I found it useless for every other type of sound aside from having some strange organs/bells. It was interesting to try it, but thank you for clearing up the confusion for me.

Can using two timbres with different FM sounds in the two create something more similar to that of the DX7?

If so, how can you calculate good harmonics for the two timbres?

Is hardclip of any use here?

P.S I saw your question abou the flux pavillion scream sound, and I don't have a patch of that specific sound on hand anymore, but I do have a similar screaming synth using the same technique I used originally to create it. would you be interested? It used FM and ring I believe.

MarPabl · Post by **MarPabl** » Sat Jun 30, 2012 11:29 pm

Read this article: Synth Secrets, Part 12: An Introduction To Frequency Modulation

3DOFan · Post by **3DOFan** » Sun Jul 01, 2012 12:06 am

qwll, I kind of get the basics of FM now, but the problem is understanding how to implement it in the R3. Emulating sounds that used multiple operators on a DX7 for example is very difficult to do, unless someone has a shortcut?

rukaav · Post by **rukaav** » Sun Jul 01, 2012 7:50 am

you will not find a classical fm architecture in r3/radias. with vpm, cross, ring, sync modulation you can only partly emulate it. is it important for you to built fm sound on r3? why not take NI FM8?

X-Trade · Post by **X-Trade** » Sun Jul 01, 2012 8:39 am

These aren't FM synths and it will be difficult if not impossible.

It's great for creating a complex waveform to then pass on to the filters. The waveshaper can also be very useful in emulating FM sounds, but it is not FM and the techniques will be different.

You want to be modulating the Osc1 Control 1, waveshape depth, etc. with envelopes.

Sometimes FM sounds have an obvious filter-like action to them, so you can emulate this with a real filter - something that wouldn't have been available on classic FM synths.

Bottom line is that you need to listen to the sound and less at how it was made, more at how you can recreate it on the synths you do have.

VPM and Cross are the only actual FM methods available on the R3/Radias, etc.
You can get a basic four-op sound if those ops are only in pairs modulating - by using VPM or Cross on each timbre.

You can also get six-op, if you assume that you use VPM for two pairs and then you have two that go straight to output.

But as I said, best way to look at it is how to closely emulate the sound itself, not how to copy exactly how it was made, because you have several different kinds of synthesis available to you.

3DOFan · Post by **3DOFan** » Sun Jul 01, 2012 11:44 am

You can also get six-op, if you assume that you use VPM for two pairs and then you have two that go straight to output.
^
What exactly does that mean?

and I'm curious, hwat would you suggest as a good hardware synth for FM?
also could I simulate 6 operators by layering sounds over eachother?(If that is possible, do you know what harmonics are compatible with eachother? I can't remmember how it works.)

X-Trade · Post by **X-Trade** » Sun Jul 01, 2012 8:40 pm

For the six-op, I just mean that you could use two timbres - osc1 on t1 & t2 both set to VPM, giving you four-op, but you've still got osc2 on both timbres to send to output, effectively giving you one six-op implementation as long as two of your operators are clean unmodulated carriers.

With VPM, you can only select harmonics for the modulator as it is 'virtual'. For cross-mod you set the modulator pitch in semitones which can be more flexible (VPM for example can't do sub-octave or fifth/etc harmonic modulators) but also yield less useful results. Again, use your ears, but generally harmonic intervals are most useful (fifth = +7semitones, octave =+12, octave & half = 19, 2 oct = 24, etc.)

3DOFan · Post by **3DOFan** » Sat Jul 07, 2012 12:11 am

is the alesis micron good at FM synthesis compared to the R3? also would I be able to create sounds like that out of a TX81Z with the Korg r3? as you said you could simulate 4 operators.

foodeater · Post by **foodeater** » Fri Jul 13, 2012 8:14 am

For the two video game sounds you're probably better off jumping straight to the sampled waveforms.

I have a radias, but I think the r3 is actually better for this because it has more old school waveforms.

For DX style sounds, the radias samples are probably better because they're smoother and glassier. I sometimes run the audio out of one timbre into another to give it lots of different stages of processing. Another advantage to the radias is with the 4 timbres I can use each one as a different "stage" of the sound.

The basic principal of FM is very fast vibrato (pitch) modulation. For fun try assigning some really fast LFOs to your oscillators and filters and hear what happens.

What DX style FM is doing is basically using the output of a entire timbre on the radias to modulate another timbre. Each operator/carrier is one whole sound. As you can imagine when you start using operators to modify each other in a feedback loop it gets very complex.

But! DX style FM didn't have different wave types(sine only) or filters and with the Radias you can do most of your sound shaping the easy way and mimic (most) of the rest using the virtual patch cords, multiple timbres and the mod sequencers. The sub-oscs in the drive section can be useful if you just want the pure FM bass sound.

Still if you want that sound. FM synths are pretty cheap. I use an old laptop with FM chips in it to get the rougher style FM sounds, but the radias does the smooth clean stuff close enough for my tastes. It's hard to get a bass sound as "solid" sounding as with an FM synth though. Probably has something to do with phase...anyway...

Micron is a pain to program....For roughly the same price you could probably grab a DX7 and dig in.

3DOFan · Post by **3DOFan** » Tue Jul 17, 2012 2:17 pm

well that was interesting, I'm realizing that the R3 isn't as bad at FM as I previously believed, it isn't as perfect as a DX series synth or TX81z, but when layered and recorded in multiple takes, you can get fairly complicated FM sounds,

I still am confused with the basics, and wish there were some patches for the R3 using FM that created the typical Brass, slap bass, fm synth piano and guitar like tones.

If there are any patches like that could someone diect me to them?

In the case there isn't, I would like to know how to make a slap bass like

http://www.youtube.com/watch?v=RuFZUnOMc7Y
or
http://www.youtube.com/watch?v=UHvg5Ert2wU <-- very beginning bass sound

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