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Slightly randomize a fader automation curve


grrdjf
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Howdy folks,

I have recorded some automation on Retro synth's filter cutoff into a region. Now I'd like to create a new region with a slight, random variation on the automation. I assumed the right way would be to copy the region, then apply a MIDI Transform to the automation data.

In the event list, I can see the automation data. So I created a Transform as per the attached screenshot (all Fader data, +-Random, 7), hit "Select Only" and confirmed that it selected 629 events; then hit "Select and Operate" and... nothing happened.

How do I transform the fader data?
 

428690316_ScreenShot2022-09-12at3_33_39PM.thumb.png.85e35e1c6584b7ff19726b8d3ab0e131.png

 

Bonus question: later, if I have a region with multiple automation lanes, how do I specify that I only want to select the data for Fader 403 since the data byte 2 column only allows me to select up to 127? Is there some other way I should be representing/selecting/operating on Fader 403?

Bonus question 2: is there some other/faster/easier way to quickly create a slightly (not fully) randomized version of the plugin automation data? Imperfect alternatives I can think of include:

  • Use Step FX instead of Retro's own filter and use the "Random deviation" action. Pro: creates slight random deviation, as desired. Con: doesn't actually result in automation data I can record and edit later if I want, has to be performed in real time, limited to things Step FX can do (ie I can't use this for other plugins with other parameters).
  • Use a midi modulator and modulate the cutoff envelope. Pro: creates slight random deviation. Can be used on other plugins with learnable parameters. Con: as above. I guess I could maybe use IAC to record the modulator automation data onto another track in real time but would that actually work, really? And it's a gross can of worms I'd rather avoid opening if there is an easier way.
  • Use the step sequencer automation lane(s) in Slide mode instead of automation curves, duplicate the region and hit "randomize" for the automation lane(s). Con: no option to slightly randomize. Hmm, 🤔 maybe I should go ask the Logic suggestion form for that. But that doesn't solve my current problem, sadly. 

 

Edited by grrdjf
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1 hour ago, grrdjf said:

In the event list, I can see the automation data. So I created a Transform as per the attached screenshot (all Fader data, +-Random, 7), hit "Select Only" and confirmed that it selected 629 events; then hit "Select and Operate" and... nothing happened.

How do I transform the fader data?

Have you tried to set a position range (instead of leaving to All)?

 

 

1 hour ago, grrdjf said:

Bonus question: later, if I have a region with multiple automation lanes, how do I specify that I only want to select the data for Fader 403 since the data byte 2 column only allows me to select up to 127? Is there some other way I should be representing/selecting/operating on Fader 403?

I am not at the studio to verify same but perhaps transforming (temporarily) fader 403 to another available one (i.e fader 33), apply the randomization and transform it back to fader 403. To do so, select them all, re-type their value accordingly (or mouse scroll the value2 down from 403 to 33), apply the randomization then do the inverse procedure to set them back to 403.

 

 

1 hour ago, grrdjf said:

Bonus question 2: is there some other/faster/easier way to quickly create a slightly (not fully) randomized version of the plugin automation data? Imperfect alternatives I can think of include:

Another approach could be via the Step Editor. I think that might also imply the back & forth conversion mentioned above.

Edited by Atlas007
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  • Solution

Thanks for the suggestions, @Atlas007, but, in order:

- Setting position range doesn't change the behaviour.

- Changing the fader number to, say, 33 doesn't change the behaviour, and in any case, it would be impossible to then transform it back up to 403 because the Transform window won't accept values higher than 127.

 - The Step Editor can't do randomization as far as I can tell. Am I missing something?

What I appear to be running into is: for this plugin and this parameter, Fader data ranges from 0-1, not 0-127 (as can be seen in the automation lane in my screenshot), and apparently the MIDI Transform window acts on the data in that form, not in the 0-127 form shown in the Events window. Relevant post with similar problem: 

 

There is a solution (also from that thread), but it's a pain, which is too bad: convert the Fader data to CC data by holding Alt, then clicking the name of the Fader in the track header and choosing an arbitrary CC number. Contrary to that thread's suggestion, I do "convert" and not "copy and convert," then MIDI Transform the CC data with +-Random, then convert it back to the desired Fader parameter by Alt+choosing it in the same menu where I got the CC from. (If I do "copy and convert" I end up with both the Fader and CC data, which is not what I want.)

This works but is too much effort to be worthwhile, I think, which is a drag. However, having done it a few times this way, I'm noticing the result doesn't sound like the kind of variation I wanted anyway. So I'm really having an XY problem, which isn't Logic's problem at all: in short, these aren't the droids I'm looking for. Back to the drawing board.

Edited by grrdjf
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23 minutes ago, Atlas007 said:

That would be nice if the Transform function could integrate the fader values and ranges ... and implement the conversion from MIDI to Fader value/range directly inside Transform

I posted a feature request on the official Logic Pro Feedback website...

Glad you did! The ability to “slightly” randomize in the Step Sequencer (Ultrabeat style) would be even easier workflow imho, so I posted a request for that.

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I wonder if you could maybe get the result you want using some other method, such as for example using the Modulator MIDI FX plug-in to randomize the cutoff of a filter in another plug-in such as Channel EQ or some other EQ.

Or even sidechain your audio through the filter of another synth such as ES2 and use a random LFO to modulate the cutoff of the ES 2 filter. 

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2 hours ago, David Nahmani said:

I wonder if you could maybe get the result you want using some other method, such as for example using the Modulator MIDI FX plug-in to randomize the cutoff of a filter in another plug-in such as Channel EQ or some other EQ.

Or even sidechain your audio through the filter of another synth such as ES2 and use a random LFO to modulate the cutoff of the ES 2 filter. 

Both fantastic suggestions of course, David, thanks for weighing in. Your ES2 suggestion got me to thinking more about modulation sources and targets.

To clarify what I  said above about it being the wrong approach: "slightly randomizing" the MIDI fader data (I've now experimented with randomizing both the value and position of the data) simply introduces jitter to the automation that gets noisier the more I do it, which, while interesting, isn't what I'm after in this case (hence: XY problem).

Having thought it over from a listening/musical perspective, what I actually want is to change the depth of a modulation signal over time (not necessarily only targeting filter cutoff, that's just what I'm experimenting with first), using a specific curve I can edit, and use that to contribute to a phrase-length groove that changes over multiple bars. Thankfully there are way easier and readily obvious ways to do this than MIDI Transform; for one thing it's interesting to see how different modulation sources interact. Even just looking carefully at the interplay between the following is instructive:

* A simple automation curve controlling Retro synth's cutoff (one long continuous ramp down over a few bars, say),

* Retro's own LFO, set reasonably slowly so I can hear its effect on the filter cutoff,

* The LFO's mod depth knob in the filter section,

* The slider next to the LFO that governs the LFO's output level, and

 * A MIDI modulator set to target Mod Wheel (which I have mapped to Retro's filter cutoff).

The 3 modulation sources (automation, modulator, LFO) interact in interesting ways--it doesn't sound to me like one supersedes the other completely, which is nice. As the automation ramps down, the "ceiling" for the filter cutoff also comes down, and thus the other modulations become more apparent.

I could add more, like a phrase-length automation curve targeting the filter-mod-by-LFO knob, another modulator that changes the characteristic of the first modulator over time, and so on. I could, as David suggests, swap in ES2 for massively more modulation possibilities. But long story short: I'm getting a musical result I like by having several simple modulation curves chaotically interact, rather than aiming to directly produce one complex curve by hand.

1027613814_ScreenShot2022-09-13at11_29_42AM.thumb.jpg.41515eec061b3336d32f7d1bfbf237cc.jpg

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On 9/13/2022 at 5:32 PM, grrdjf said:

But long story short: I'm getting a musical result I like by having several simple modulation curves chaotically interact, rather than aiming to directly produce one complex curve by hand.

Great. Good to hear and thank you for sharing your results. 

I wish we could have "Relative" and "Trim" automation modes for all parameters, not just volume. This would allow you to write a Relative random curve while keeping your absolute curve for example as a ramp down as in your example, to somewhat randomize the ramping down of the filter cutoff. 

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