Now this article on WIkipedia reads that
This is my intuition as well. Phase and frequency are interchangeable. Or not? Please explain this to me.For a single large sinusoidal signal, PM is similar to FM
This is my intuition as well. Phase and frequency are interchangeable. Or not? Please explain this to me.For a single large sinusoidal signal, PM is similar to FM
I second this. It took me a while to get a grasp on this as well. If you have a signal x(t) = sin(w*t) and a modulation signal f(t) then:
Code: Select all
float phaseTick(float freq, float PM) // freq and PM both normalized in [0, 1], output is in [0, 1]
{
phase = phase + freq; //phase is initialized at 0
phase = frac(phase); //frac is the fractional part
return frac(phase + PM);
}
Code: Select all
float phaseTick(float freq, float FM) // freq and FM both normalized in [0, 1], output is in [0, 1]
{
phase = phase + freq + FM; //phase is initialized at 0
phase = frac(phase); //frac is the fractional part
return phase;
}
It is. It is also broken as soon as you apply envelope on modulator level. It's now integral of sine()*env(), not just sine(), fast/short env will produce additional modulation of the carrier (it might be roughly equivalent of differential of modulator's volume envelope as additional modulation of carrier's frequency).
Markus Krause wrote: ↑Fri Oct 22, 2021 12:41 am"From a technical point of view, conventional 'FM synthesizers' actually use phase modulation to generate sound - but for historical marketing reasons they are advertised as 'FM synthesizers'. The traditional method, however, is limited to bell-like sounds and often produces an unpleasant, metallic sound.
Weird generalizations there.Markus Krause wrote: ↑Fri Oct 22, 2021 12:41 amSome analog synthesizers can do true FM. However, this suffers from the lack of precision of the oscillators, which creates an inharmonic sound that is not particularly useful musically.
Right. The most common VCO is a "sawtooth core" that basically feed a capacitor from a voltage-controlled current-source (whether linear or 1V/oct) and a comparator that rapidly discharge the capacitor when it hits a certain threshold. This is a very simple design, but it's kinda hard to get it to run backwards.foosnark wrote: ↑Wed Dec 01, 2021 7:05 pm
Linear FM on analog oscillators typically has limited depth of modulation before it skews the tuning sharp. (Because an analog VCO's core is based on charging/discharging a capacitor, it can't go "backwards" if you push the core frequency below 0Hz.) TZFM (thru-zero linear FM) is available on a few analog VCOs, using some extra circuitry to invert the phase -- but in my experience is less than perfect. (Really badly less than perfect in the case of Doepfer A-110-4.) But both TZFM and PM are super easy on a digital oscillator.
Thank you! Yes, exactly. The analytic DC correction was added to KarmaFX Synth Modular 2 last year, while adding true through-zero FM (TZFM). It's called Exponential Sync (EXS), and in many cases I prefer the sound of this Synced Exponential FM to Linear FM/Phase Modulation.
Very interesting paper.karmafx wrote: ↑Mon Dec 27, 2021 2:13 amThank you! Yes, exactly. The analytic DC correction was added to KarmaFX Synth Modular 2 last year, while adding true through-zero FM (TZFM). It's called Exponential Sync (EXS), and in many cases I prefer the sound of this Synced Exponential FM to Linear FM/Phase Modulation.
© KVR Audio, Inc. 2000-2020
Submit: News, Plug-ins, Hosts & Apps | Advertise @ KVR | Developer Account | About KVR / Contact Us | Privacy Statement