someone please explain what is FM modulation for a OSC ?

[hivkorn]

I'm not sure to understand 100 % ,i know some stuff from electricity , ex: f=1/t i understand how it does
but i don't understand fm mod , what it does to the waveform and why do it ?
pictures with/ and explanation are welcome
Thx.

[vurt]

it is the same as using an lfo to modulate frequency, only at a faster rate.
it's good for creating those fm bell tones n suchlike

[CHOOS]

easiest way to see how it works it to modulate a sine with another Low Frequency sine.
then gradually increase intensity and raise the frequency while looking at SPAN by Voxengo
https://www.voxengo.com/product/span/ (FREE)

then see what happens when you change the modulator to a triangle, square, saw, custom wave or wavetable.
then modulating the modulator by volume or other osc's etc etc etc

This might not be the answer you're looking for but let me know if I can help in any other way

[DJ Warmonger]

Well, basically it's frequency modulation. However, it can lead to quite interesting and unexpected results. Everything is explained in this book: http://www.burnkit2600.com/manuals/fm_t ... ations.pdf

[hivkorn]

Thx guy it seems i have understand correctly since the beggining , but to be sure i will try with the voxengo to see what s happens.but why add a fm know instead a full lfo with a sync function ? A way more easy to control and obtain the sound we want !

[zerocrossing]

Thx guy it seems i have understand correctly since the beggining , but to be sure i will try with the voxengo to see what s happens.but why add a fm know instead a full lfo with a sync function ? A way more easy to control and obtain the sound we want !

I think you’re maybe confusing Frequency Modulation with what a DX7 does, which is actually Phase Modulation. They’re different. They’re both different then oscillator sync.

For a long time, I avoided DX style FM because I thought it was too complex. It’s actually not that complicated, but there’s a lot of options to explore. My advice is to look for a simple FM synth. I used FM4 for the iOS. When you can see how each envelope is set up next to other envelopes, it’s easier to get what’s going on.

[hivkorn]

When you re talking of phase modulation you re talking about the same phase of electricity rules ?

[OllyAudio]

it is the same as using an lfo to modulate frequency, only at a faster rate.
it's good for creating those fm bell tones n suchlike

Lfo - Single modulator (1 wave). In fm synthesis, not only sinus (1 harmonic, similar to LFO) can participate, but also complex types of waves - Pulse, triangle .... In these wave forms there are several harmonics. What gives a special timbre to the sound of FM.

[vurt]

it is the same as using an lfo to modulate frequency, only at a faster rate.
it's good for creating those fm bell tones n suchlike

Lfo - Single modulator (1 wave). In fm synthesis, not only sinus (1 harmonic, similar to LFO) can participate, but also complex types of waves - Pulse, triangle .... In these wave forms there are several harmonics. What gives a special timbre to the sound of FM.

indeed, any oscillator shape can be used, or even for more fun, two (or more) different waves being used in combinations

[OllyAudio]

indeed, any oscillator shape can be used, or even for more fun, two (or more) different waves being used in combinations

When realistic metal cymbals are created, they use a pulse wave as a modulator. The pulse wave is modulated by another oscillator (pulse, triangle) This causes very bright harmonics in large numbers. Such harmonics give the sound metallic shades. Then put BP - filter (HP filter) and get metal percussion. Next - effects.

[OllyAudio]

https://drive.google.com/open?id=1Lq8fc ... Y95KPV88Wk

This is an example of how metal percussion is made using FM synthesis. I used a pulse wave to modulate the sawtooth. tuned filter envelopes and amplitudes. I added a BP filter and a bit of white noise for sparkling. Of the additional effects - Ambient reverb, equalizer and echo. I've got realistic Trip-Hop hats.

[thecontrolcentre]

Trip-Hop hats.

[DonaldM75]

Well, basically it's frequency modulation. However, it can lead to quite interesting and unexpected results. Everything is explained in this book: http://www.burnkit2600.com/manuals/fm_t ... ations.pdf

I second the motion on this book. I first got it when it was originally published back in the 80's. It was written to explain the then new Yamaha DX7's FM structure for patch creation.

[lnikj]

I'm not sure to understand 100 % ,i know some stuff from electricity , ex: f=1/t i understand how it does
but i don't understand fm mod , what it does to the waveform and why do it ?
pictures with/ and explanation are welcome
Thx.

Download VCVRack (https://vcvrack.com), just the basic package, install and run, right click and load 2 VCO-1s, a Scope and an Audio module and patch as below. Note that the VCO-1s are switched to 'digital'.

Play with the frequency knobs and watch the scope. On the left is the modulator, on the right the carrier. Try patching the other waveforms and seeing what it looks and sounds like. Try the square and saw waves on the carrier VCO-1, switched to 'Analog', at high frequencies and listen to the (unavoidable) aliasing.

HTH