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Gharwen
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Joined: 08/02/2013 - 07:03
Modular Synth: Frequency of LFO and Noise LF

I'm experimentig al littel bit with the modular synth, trying to create sounds like crickets, grashoppers, rain, thunder...

In most patch tutorials I found they talk about frequencies, especially for the LFO or Noise LF.

Can anybody tell me the LFO range and the Noise LF frequency?

SToons Music
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Joined: 03/01/2018 - 02:48
Tricky question unless the

Tricky question unless the Dev or someone who has access to the source code can confirm, however, here's the difficulty with a simple response (unless I'm missing something) :

By LFO I assume you mean the Mini LFO. The Mini LFO is directly linked to the song tempo, therefore there is no fixed freq range, it varies as a multiple of the tempo.

For example, look at the Caustic file I posted. It is simply the Mini LFO connected to the output. It produces a continuous tone. While it plays, if you open the dialog box where you load and save files, and then you adjust the tempo, you will hear the frequency raise as you raise the pitch and the inverse.

However, there are interesting ways for you to adjust. If you make a single Modular patch with the Noise Generator, make a one measure song, export as wave, then load the audio into the wave editor and use the spectrum to view how the freq rolls off.

You can repeat the experiment with a Mini LFO, rate set to the lowest and repeat once more with the rate set to the highest setting.

You can also use the Guess Pitch option in the editor and translate the pitch into a frequency if the editor recognizes the low freq (obviously won't work with noise though).

With noise, if you want to shape specific frequencies, consider using a band pass or low pass filter in the mod itself or add one as an effect... this will give you far greater control even in the low freq ranges. You can even use full white noise and filter it instead. Again allows better control as the Noise LF output rolls off so its very hard to control specific freq compared to using white noise as the source due to the fact that white noise has equal power in all frequencies (the perfect marble to sculpt!).

Different tempos will yield different results with the Mini LFO but the Noise LF remains constant.

I tried all three and did screenshots of the results but I dont know how to post pics.

Caustic Song file (optional): 

paulovski
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Joined: 09/19/2012 - 06:13
You might be better off not

You might be better off not using a synchronized LFO. All the modsynth oscillators can, with a bit of help from a few extra modules, oscillate at low frequencies. Though the wave generator does the best job of it (more extra modules though). It depends on what final volume envelope you want (assuming you want one). For a default on/off envelope, the setup's pretty simple.

There's a couple of examples here. In both of them, there's a 2>1 mixer, bottom right. It's output level controls LFO frequency. If you play with the AR envelope in the first example, you can set up some petty cool effects, but you won't have a constant LFO frequency. As long as it's two outputs are equally mixed you can do what you like with the parameters of the DADSR in the second example. It won't effect the LFO rate.

Don't worry too much about what frequencies the tutorials tell you what to use. Your ears will tell you if it's right.

Caustic Song file (optional): 

SToons Music
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Joined: 03/01/2018 - 02:48
@paulovski Unfortunately,

@paulovski Unfortunately, whether or not the "Note Sync" is activated or not, the LFO is still subject to the song tempo. If you open the example I posted, switch the sync off and then adjust the song tempo, the pitch still varies, it just doesn't retrigger at the attack of each new note. Dealing with "approximate" values is a major negative when dealing with sound design. Having to factor in multiples of the tempo is not a plus, but even with your "solutions" math has to factor into the equation to achieve the desired results.

It is never a truly "unsychronized" LFO.

So in the end you're right, at least in my own somewhat (very?) limited opinion, it would be easier to control one of the other generators. I have almost no complaints regarding Caustic but the ability to click on a knob and manually enter a specific value would be very helpful.

TheRektafire
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Joined: 08/27/2014 - 10:45
On top of what everyone else

On top of what everyone else has said above, I think the lfo in the modular isn't even perfectly synced to the tempo. I remember a few months ago making an arpeggiated 303 patch in the modular with a filter controlled by an lfo. The filter sweep would still slowly drift off beat even with it synced to the tempo and I went on here asking about it and I was informed of that.

paulovski
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Joined: 09/19/2012 - 06:13
Err yeah. Dont use the mini

Err yeah. Dont use the mini LFO. What with it always being synced to tempo. Use one of the other ones.

And yes. Give it a few minutes, and the mini LFO drifts out of sync unless you retrigger it in Note sync on mode. And there's no phase lock in note sync off mode.

SToons Music
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Joined: 03/01/2018 - 02:48
@TheRektafire. Yeah I noticed

@TheRektafire. Yeah I noticed that but in all fairness the entire program is subject to a slight drift. I noticed that a while back when exporting stems and working between Caustic and Cakewalk and also when I recorded in Caustic wave editor using a click track from an external metronome. Caustic can drift when doing straight acoustic recording but everything done in the program itself locks together so it has little or no impact on the long run except when syncing to recordings. At least that's my experience (Samsung S6 and Acer tablet).

But me, I ain't the type to bitch! It's usually easier to just work around such problems and most experienced with DAWs and such can easily adapt to any music software within reason. Rej has done a beyond phenomenal job and the fact it's ported across platforms is brilliant so I'm not gonna ask for shit, if it gets developed further, great, if not, I'm happy using it as is.There is no tool out there that can satisfy my every need.

That said, there are a few, and only a few, programs out there for the Android OS that are better suited to sound design as they allow more fine tuning of the parameters referenced by the OP. No names, I'm not in the business of advertising other apps on the Caustic site.