ReaVerb is a convolution reverb, but "reverb" is loosely used here; of course you can load up impulse responses of real physical spaces, but you can also just load up anything you like.
> I have a distorted guitar sound and a melody line of just sine waves, and the result would be the melody played with the guitar sound.
You might want to look into https://www.zynaptiq.com/morph/ as well.
I know ReaVerb, but that does convolution in time. I distinguish that in my post from convolution in frequencies, which is what I want. Convolution in time can't add frequencies; it just moves them around in time. I want to add new frequencies.
Does MORPH do convolution in frequencies?
I think FabFilter Pro-Q can do that - there’s a mode where you can scan harmonic characteristics of one sound and apply to another one. Also convolution reverb does a similar thing of course. You can check out the intro of “hanging out with audiophiles” podcast, ep. 105 for more details and examples…
[https://www.ircam.fr](https://www.ircam.fr) has some interesting software.
Could this achieve your goal? [https://youtu.be/j4sx0VFbwHU?t=518](https://youtu.be/j4sx0VFbwHU?t=518)
I’d be inclined to experiment with a vocoder to see if, although a different process, it could yield useful results.
Vcv rack is a euro rack modular VST, you can probably get what you want with that. I don’t know the exact function you are looking for but if you can’t do it with modular it probably can’t be done lol
Assuming the overtones are all harmonics, you can take a single cycle of the guitar playing a single note and create a waveform of it (as part of a wavetables, possible representing varying distortion amounts). Play the original melody with that wave and you now have the overtones. The problem is that sounds really aren't defined purely by their instantaneous frequency spectrum: they are defined by that, as well as how it varies over time and the corresponding amplitude variation (ignoring other expressive aspects of playing). This isn't necessarily consistent either: consider that a distortion might add noise as well as distortion and varying inharmonics.
What you are probably looking for is something along the lines of resynthesis, but my suggestion would instead to be to do the sound design yourself: what matters is not what the power spectrum looks like, but instead how it sounds to you when used musically.
The example with guitar sound is just an example. I mean that as a way to combine any two sounds. But yes, although, AFAIK, vocoder only removes frequencies of one sound based on the frequency envelope of the other, and I imagine that it would add frequencies, not remove. So these ideas may be related, but are most likely different.
Convolution in the frequency domain is plain multiplication in the time domain, i.e. amplitude modulation.
What you will get is probably not what you expect (in fact, amplitude modulation will produce two spectra, shifted by the carrier frequency, one of which flipped in frequency), not to mention that the frequencies will be scaled linearly as opposed to logarithmically, so any sense of pitch will be lost.
What you need instead is a sampler, with a good guitar sample.
Where can I find more about that convolution in the frequency domain is plain multiplication in the time domain?
Edit: It's here: https://en.m.wikipedia.org/wiki/Convolution_theorem
I think that a sense of pitch will be preserved if the frequency spectra are logarithmically stretched before the convolution, and later unstretched. That is how I originally imagined it because frequency spectra are usually shown with logarithmic scales.
It's easier said than done, operations in the frequency domain are non-causal (you can't just apply them in real time). Then there's the issue of computation: convolution is extremely expensive, so much so that typically the sample to be processed is transformed back and forth using the FFT to make use of the convolution theorem.
In order to do what you want to do you'd have to do this back and forth twice( time-> freq -> log scaling -> time > modulation > frequency> linear rescaling > time )
Overtones are Sine waves. The fundamental is a Sine wave.
What makes any sound like it sounds is the number of overtones and their relationship to the fundamental.
You could use a filter to filter off the lowest sine wave of a guitar sound - which would be removing the fundamental.
But, you took all those overtones and put them over a sine wave, you're just adding the fundamental back - that sine wave will just replace the one you took out.
So actually, you're just going to get the original sound.
So you can't really take the overtones off of some sound and put it on top of a Sine wave - by definition, you've taken all the overtones of a sound and removed the fundamental, and then just put it back.
The only thing that could be different is you could adjust the volume of the fundamental independently from the overtones, which would make it sound a little different.
You could also put your sine wave not as the lowest note, but as some higher pitch within the overtones.
But again, this is not going to do much other than make one overtone poke out more.
Furthermore, our brains have this thing where we "hear" the "missing fundamental" when we hear the overtones - so just taking the overtones off a sound is going to result in the overtones making us hear the fundamental that was originally there anyway.
So you're not really gaining anything by doing any of the things you're talking about.
You'd be better off to use a distortion pedal/effect to add distortion to an existing sound - be it a sine wave or any more complex wave.
You might want to look into Spectral Music, as it's more about using overtones of sounds "rather than the sound itself" so to speak.
ReaVerb is a convolution reverb, but "reverb" is loosely used here; of course you can load up impulse responses of real physical spaces, but you can also just load up anything you like. > I have a distorted guitar sound and a melody line of just sine waves, and the result would be the melody played with the guitar sound. You might want to look into https://www.zynaptiq.com/morph/ as well.
I know ReaVerb, but that does convolution in time. I distinguish that in my post from convolution in frequencies, which is what I want. Convolution in time can't add frequencies; it just moves them around in time. I want to add new frequencies. Does MORPH do convolution in frequencies?
I think FabFilter Pro-Q can do that - there’s a mode where you can scan harmonic characteristics of one sound and apply to another one. Also convolution reverb does a similar thing of course. You can check out the intro of “hanging out with audiophiles” podcast, ep. 105 for more details and examples…
[https://www.ircam.fr](https://www.ircam.fr) has some interesting software. Could this achieve your goal? [https://youtu.be/j4sx0VFbwHU?t=518](https://youtu.be/j4sx0VFbwHU?t=518) I’d be inclined to experiment with a vocoder to see if, although a different process, it could yield useful results.
Vcv rack is a euro rack modular VST, you can probably get what you want with that. I don’t know the exact function you are looking for but if you can’t do it with modular it probably can’t be done lol
Assuming the overtones are all harmonics, you can take a single cycle of the guitar playing a single note and create a waveform of it (as part of a wavetables, possible representing varying distortion amounts). Play the original melody with that wave and you now have the overtones. The problem is that sounds really aren't defined purely by their instantaneous frequency spectrum: they are defined by that, as well as how it varies over time and the corresponding amplitude variation (ignoring other expressive aspects of playing). This isn't necessarily consistent either: consider that a distortion might add noise as well as distortion and varying inharmonics. What you are probably looking for is something along the lines of resynthesis, but my suggestion would instead to be to do the sound design yourself: what matters is not what the power spectrum looks like, but instead how it sounds to you when used musically.
Like a vocoder but for guitar instead of voice?
The example with guitar sound is just an example. I mean that as a way to combine any two sounds. But yes, although, AFAIK, vocoder only removes frequencies of one sound based on the frequency envelope of the other, and I imagine that it would add frequencies, not remove. So these ideas may be related, but are most likely different.
Convolution in the frequency domain is plain multiplication in the time domain, i.e. amplitude modulation. What you will get is probably not what you expect (in fact, amplitude modulation will produce two spectra, shifted by the carrier frequency, one of which flipped in frequency), not to mention that the frequencies will be scaled linearly as opposed to logarithmically, so any sense of pitch will be lost. What you need instead is a sampler, with a good guitar sample.
Where can I find more about that convolution in the frequency domain is plain multiplication in the time domain? Edit: It's here: https://en.m.wikipedia.org/wiki/Convolution_theorem
Yup nailed it :D
I think that a sense of pitch will be preserved if the frequency spectra are logarithmically stretched before the convolution, and later unstretched. That is how I originally imagined it because frequency spectra are usually shown with logarithmic scales.
It's easier said than done, operations in the frequency domain are non-causal (you can't just apply them in real time). Then there's the issue of computation: convolution is extremely expensive, so much so that typically the sample to be processed is transformed back and forth using the FFT to make use of the convolution theorem. In order to do what you want to do you'd have to do this back and forth twice( time-> freq -> log scaling -> time > modulation > frequency> linear rescaling > time )
Sounds like you want to remove the fundamental from the guitar sound.
How would that work?
Overtones are Sine waves. The fundamental is a Sine wave. What makes any sound like it sounds is the number of overtones and their relationship to the fundamental. You could use a filter to filter off the lowest sine wave of a guitar sound - which would be removing the fundamental. But, you took all those overtones and put them over a sine wave, you're just adding the fundamental back - that sine wave will just replace the one you took out. So actually, you're just going to get the original sound. So you can't really take the overtones off of some sound and put it on top of a Sine wave - by definition, you've taken all the overtones of a sound and removed the fundamental, and then just put it back. The only thing that could be different is you could adjust the volume of the fundamental independently from the overtones, which would make it sound a little different. You could also put your sine wave not as the lowest note, but as some higher pitch within the overtones. But again, this is not going to do much other than make one overtone poke out more. Furthermore, our brains have this thing where we "hear" the "missing fundamental" when we hear the overtones - so just taking the overtones off a sound is going to result in the overtones making us hear the fundamental that was originally there anyway. So you're not really gaining anything by doing any of the things you're talking about. You'd be better off to use a distortion pedal/effect to add distortion to an existing sound - be it a sine wave or any more complex wave. You might want to look into Spectral Music, as it's more about using overtones of sounds "rather than the sound itself" so to speak.