A question about FM synth ratios and Algoritm

[thedjjudah]

Hey all,

I was just wondering why I still get FM when modulating a carrier that has a ratio/frequency of 0.00. Is this a bug in Algoritm? It would make sense for there to be no sound at all, and when the modulator is 0.00 there's no change, except if I modulate the 0.00 modulator.

This is a little confusing, and pretty cool, but I just want to understand what's going on.

Thanks

[mimidancer]

Hey all,

I was just wondering why I still get FM when modulating a carrier that has a ratio/frequency of 0.00. Is this a bug in Algoritm? It would make sense for there to be no sound at all, and when the modulator is 0.00 there's no change, except if I modulate the 0.00 modulator.

This is a little confusing, and pretty cool, but I just want to understand what's going on.

Thanks

if the operator is 0.0 and the carrier is 1 you will hear 1. if both are zero you hear nothing.

[Pepin]

Hey all,

I was just wondering why I still get FM when modulating a carrier that has a ratio/frequency of 0.00. Is this a bug in Algoritm? It would make sense for there to be no sound at all, and when the modulator is 0.00 there's no change, except if I modulate the 0.00 modulator.

This is a little confusing, and pretty cool, but I just want to understand what's going on.

Thanks

if the operator is 0.0 and the carrier is 1 you will hear 1. if both are zero you hear nothing.

I think the question is about when the operator is 1.0 and carrier is 0.0 though. It's not immediately clear to me what's happening in that situation. It's definitely not silent.

[mimidancer]

if the operator is 0.0 and the carrier is 1 you will hear 1. if both are zero you hear nothing.

I think the question is about when the operator is 1.0 and carrier is 0.0 though. It's not immediately clear to me what's happening in that situation. It's definitely not silent.

if the modulater is at zero but the carrier is on you will just hear the carrier unmodulated. 0+1=1 get it?

[Pepin]

I think the question is about when the operator is 1.0 and carrier is 0.0 though. It's not immediately clear to me what's happening in that situation. It's definitely not silent.

if the modulater is at zero but the carrier is on you will just hear the carrier unmodulated. 0+1=1 get it?

I understand that much, but OP is asking about the carrier frequency being zero not the modulator (e.g. carrier 0, modulator 1).

[mimidancer]

if the modulater is at zero but the carrier is on you will just hear the carrier unmodulated. 0+1=1 get it?

I understand that much, but OP is asking about the carrier frequency being zero not the modulator (e.g. carrier 0, modulator 1).

if the modulator is at 1 and the carrier is at 0 you will hear the modulator so long as it is at audio rates. M+C=sound heard so 1+0=1 you hear the carrier or 0+1=1 you hear the modulator. the operators and carriers are summed. Understand? so long as one of them has frequency you will hear something. The actual formula takes in the amplitude as well. it is x(t)=A(t)cos[ωct+I(t)cos(ωmt+ϕm)+ϕc] or break it into y(t) = A cos(2πfct + kf∫t x(α)dα + φ0) A is the ampitude kf is the frequency alteration as a constant and φ0 is the phase offset. followed by. f(t) = C + D sin(2πMt) this lets C is the pitch of the carrier and D is the depth of modulation. Basically the amount of modulation. But if you just look at one carrier and one modulator it is easy to hear as 0+1=1 or 1+0=1.

[Pepin]

I understand that much, but OP is asking about the carrier frequency being zero not the modulator (e.g. carrier 0, modulator 1).

if the modulator is at 1 and the carrier is at 0 you will hear the modulator so long as it is at audio rates. M+C=sound heard so 1+0=1 you hear the carrier or 0+1=1 you hear the modulator. the operators and carriers are summed. Understand? so long as one of them has frequency you will hear something. The actual formula takes in the amplitude as well. it is x(t)=A(t)cos[ωct+I(t)cos(ωmt+ϕm)+ϕc] or break it into y(t) = A cos(2πfct + kf∫t x(α)dα + φ0) A is the ampitude kf is the frequency alteration as a constant and φ0 is the phase offset. followed by. f(t) = C + D sin(2πMt) this lets C is the pitch of the carrier and D is the depth of modulation. Basically the amount of modulation. But if you just look at one carrier and one modulator it is easy to hear as 0+1=1 or 1+0=1.

I'm far from an expert on this, but I guess I'm struggling to apply your explanations to the actual behavior of Algoritm.
If you set this up, you don't just hear the modulator. Can you explain why that is?
No other FM synth I've used actually lets you set an operator's frequency to 0.

alg.png (102.82 KiB) Viewed 6709 times

[mimidancer]

if the modulator is at 1 and the carrier is at 0 you will hear the modulator so long as it is at audio rates. M+C=sound heard so 1+0=1 you hear the carrier or 0+1=1 you hear the modulator. the operators and carriers are summed. Understand? so long as one of them has frequency you will hear something. The actual formula takes in the amplitude as well. it is x(t)=A(t)cos[ωct+I(t)cos(ωmt+ϕm)+ϕc] or break it into y(t) = A cos(2πfct + kf∫t x(α)dα + φ0) A is the ampitude kf is the frequency alteration as a constant and φ0 is the phase offset. followed by. f(t) = C + D sin(2πMt) this lets C is the pitch of the carrier and D is the depth of modulation. Basically the amount of modulation. But if you just look at one carrier and one modulator it is easy to hear as 0+1=1 or 1+0=1.

I'm far from an expert on this, but I guess I'm struggling to apply your explanations to the actual behavior of Algoritm.
If you set this up, you don't just hear the modulator. Can you explain why that is?
No other FM synth I've used actually lets you set an operator's frequency to 0.
alg.png

Easy peasy. you are not taking into account the amplitude. Set the volumes on both operators to 12 o'clock. then switch them back and forth. if you are adding amplitude it will create harmonics. raising the volumes adds harmonic distortion.

[Pepin]

I'm far from an expert on this, but I guess I'm struggling to apply your explanations to the actual behavior of Algoritm.
If you set this up, you don't just hear the modulator. Can you explain why that is?
No other FM synth I've used actually lets you set an operator's frequency to 0.
alg.png

Easy peasy. you are not taking into account the amplitude. Set the volumes on both operators to 12 o'clock. then switch them back and forth. if you are adding amplitude it will create harmonics. raising the volumes adds harmonic distortion.

Thanks, you're right I was forgetting about the carrier's amp still being applied despite the 0 frequency.

[thedjjudah]

Thanks, everyone!

[selig]

One thing that's interesting, and that I can't explain, is the difference between both modulator and carrier at "1" vs mod @ 1 and car @ "0". The former is all (even AND odd) harmonics while the latter is just odd.
From what I can gather (the manual never mentioned a ratio of zero), it is indeed what you would expect: a ratio of zero equals DC (no "frequency"). But this is only measurable in waveforms other than sine, where a ratio of zero outputs a full negative DC signal. You can see this by recording the output to a new audio track. But a sine wave outputs nothing (AFAICT) at a Frequency Ratio of zero, so I'm not sure what exactly is going on.
Anyone with further insights?

[mimidancer]

One thing that's interesting, and that I can't explain, is the difference between both modulator and carrier at "1" vs mod @ 1 and car @ "0". The former is all (even AND odd) harmonics while the latter is just odd.
From what I can gather (the manual never mentioned a ratio of zero), it is indeed what you would expect: a ratio of zero equals DC (no "frequency"). But this is only measurable in waveforms other than sine, where a ratio of zero outputs a full negative DC signal. You can see this by recording the output to a new audio track. But a sine wave outputs nothing (AFAICT) at a Frequency Ratio of zero, so I'm not sure what exactly is going on.
Anyone with further insights?

would you screengrab the output and the synth itself? I'm always up for a mystery. I love scooby doo.

[deanthomas]

It sounds like what you're experiencing isn't a bug but rather how the modulation process works in Algoritm. Even with a frequency ratio of 0.00, the modulator can still affect the carrier, creating changes in the sound. The modulation introduces phase changes, which can result in FM-like effects. It's a bit counterintuitive, but that's likely why you're still hearing FM.my perfect hotel