How To Modulate The Frequency Of A Sample?

Can I modulate the frequency of a sample with Renoise effects?

What exactly do you mean by ‘modulate the frequency’?

Do you mean the pitch? You want to modulate the pitch to create a vibrato effect?

Or perhaps you want to create a sweeping effect, and you want to modulate the frequency of a filter which is applied to the sound?

Can you possibly give an example of the sound you are trying to create? Maybe a YouTube clip or MP3 or something like that?

Hi, I mean, a very “simple” thing. Take any sound, for example, a sine wave. I want to modulate (via automation) the frequency (pitch) but not in the 12 note equal tempered scale. So, if I have a C4 (261.626 hz), I want to modulate it to 270, 271… back to 258 hz , etc.

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I see. I guess you are doing some kind of microtonal work, or something similar? Unfortunately, there is no real method for handling this directly in Renoise yet, so it will be very difficult to set the notes with the level of accuracy that you are probably looking for. If you are using a VSTi synth or sample-player which supports fine-tuning, then it may be possible to automate that in Renoise and get something pretty close to what you want.

I find one way, but I dont know if it is correct. create an empty sample > DC Offset > RingMod. I modulate the frequency with ringmod frequency automation, and I can modulate the amplitude with DC Offset automation. But:
“DC offset is usually undesirable. For example, in audio processing, a sound that has DC offset will not be at its loudest possible volume when normalized (because the offset consumes headroom), and this problem can possibly extend to the mix as a whole, since a sound with DC offset and a sound without DC offset will have DC offset when mixed. It may also cause other artifacts depending on what is being done with the signal.”

In this way, Im introducing DC offset in the mix???

You can get rid of DC offset fairly effectively using a highpass filter with the frequency set very low. If fine modulatable control of pitch/frequency is what you’re after I guess this is about the best way to do it. “classic FM” type synthesis in which you modulate the frequency at a repetetive frequency that is itself audible is very limited however.
You can cross amplitude modulate two samples together in non real time in the sample editor. It would be nice to see a frequency modulation option here in future for more timbral freedom.

Yes and no.

“DC offset” typically refers to a static amount of shift in a signal, which is undesirable because it’s constant and will interfere with the signals, limit your headroom, etc. But when you feed the DC offset into a RingMod, you’re actually turning it into an oscilator. It’s no longer a static offset at that point, since it’s being modulated by the RingMod effect, and you’ve transformed it into an evolving waveform instead.

Take a look at a demo I posted recently which takes advantage of a similar technique:
Renoise Native Monophonic Synthesiser :)

I was going to suggest this earlier, but I wasn’t sure if it would be suitable for you. If you do this, then you’re really just synthesising your own new sounds, and you can of course tune them any way you want to. You only have a sine, triangle, sawtooth, squarewave, etc., to work with, but if you are comfortable with designing synth patches then it’s not that difficult to turn these basic waveforms into a nice instrument, which you could then use for microtonal music.

So, the RingMod is nice to use for this purpose, but I don’t think it’s really suitable as a method of tuning existing sounds.

Hi, thanks for the help. Can you explain a little more “cross amplitude modulate two samples together in non real time”
Im learning synthesis and sound manipulation, its very interesting, cause you know what are you doing, instead to just load a preset from a vst (I do that, too). It would be cool and simple to develop a frequency modulation option.
Another question, you change the timbre doing that? I think you only change the pitch, the timbre is another quality. But Im learning, so Im not sure.

Right, its good for doing that, ring modulation, but for this specific task not. Because it multiplies two signals.
But it is rare, there must be a way to do it in Renoise. Ringmod seems more complex than this. I need some thing like ringmod without the multiplying of signals…

Actually classic FM Synthesis, patented by Yamaha and used in the likes of the DX7, is in fact Phase Modulation and not really Frequency Modulation. The results are pretty much effectively the same though.

_licensed to_ Yamaha, I think... not to nit pick... Yamaha hardly invented it, but they did make a market for it so good on them anyway.

Yeah invented by this guy. http://en.wikipedia.org/wiki/John_Chowning Seems you’re right and patent is actually owned by Stanford University and licensed to Yamaha, although this did mean other synth manufactures had to come up with slightly different methods.

Have to admit i only recently discovered that FM synthesis isn’t actually based on frequency modulation on the whole.

As to orignal topic. Is neither the Vibrato command, or LFO in the Instrument Editor what you desire? All you are asking for in the first post is to modulate the frequency and both of these will achieve that.

Phase modulation eh? Learn something new everyday! I meant really in terms of getting that FM sound.

@Capitan I tried to figure out how you do that sample cross modulation thing but I coudn’t find the tool. I definitely remember doing it in a previos release of renoise…? Has this feature been removed?

Do you mean the Mix-Paste option ?

Mix-Paste and other Copy/Paste Operations

No… I need to modulate the Hz precisely. Like in the RingMod.

Ah yes! There it is alright. Thanks man!