Can an LFO be used to create frequency modulation?
If I have a sine wave lfo modulated by a long series of other lfo's at various speeds could I create a basic fm system?
The LFO's aren't audible but if I were to route them to 3-4 oscillators would the effect be indistinguishable from traditional fm? Im going to experiment with the above but I thought it worth asking if anyone has already achieved something similar.
LFO Frequency Modulation
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- KVRist
- 427 posts since 24 Feb, 2015 from Stockholm, Sweden
Well, you won't get the typical FM sounds out of it...
FM at low frequency is basically just pitch mod. You could try this with Dexed or other FM synths which allow below audio rate operators.
It won't matter that you string a bunch of them together, you're still just making a vibrato...
Basic FM is mostly useful when you have modulators operating at integer multiples of the carrier frequency. From there you can then dial in more metallic and dissonant sounds by adjusting pitch.
So unless your LFO comes close to audio rate you will probably not get the desired effect.
If you experience any interesting results I'd love to hear about them though! No reason to not give it a shot! By modulating the LFO:s you might just be able to generate enough side bands at audio rate to get some unanticipated results.
FM at low frequency is basically just pitch mod. You could try this with Dexed or other FM synths which allow below audio rate operators.
It won't matter that you string a bunch of them together, you're still just making a vibrato...
Basic FM is mostly useful when you have modulators operating at integer multiples of the carrier frequency. From there you can then dial in more metallic and dissonant sounds by adjusting pitch.
So unless your LFO comes close to audio rate you will probably not get the desired effect.
If you experience any interesting results I'd love to hear about them though! No reason to not give it a shot! By modulating the LFO:s you might just be able to generate enough side bands at audio rate to get some unanticipated results.
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- KVRAF
- 3319 posts since 16 Jan, 2005 from Ottawa, Ontario
Yes. you just need to get well into the audible range- check out sytrus
"I never did care for music much. It's the high fidelity!" — Flanders & Swann
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- KVRist
- Topic Starter
- 298 posts since 9 Feb, 2015
A pitch tracker could work perhaps? I could set a pitch tracker to monitor the output of an oscillator and then map the tracker to the fine pitch control of another oscillator. I did ask about pitch tracking software a while back but I dont think the thread yielded much. The task would require a tracker that monitors tiny pitch shifts. Is there an M4L device that can do this?
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- KVRist
- 427 posts since 24 Feb, 2015 from Stockholm, Sweden
It's not really clear what you're trying to achieve... Why not just use two oscillators that get the pitch from the same source (eg midi)? If you want them at different pitches just tune the modulator to whatever sounds good.
