Feedback Loops with Bitwig

Tutorial | Oct 25, 2024

In this video, I demonstrated how to create feedback loops in Bitwig Studio's grid using noise sources, delay, and auto gain to maintain stable levels and explore unique soundscapes. I showed how to incorporate various effects, such as phasers and filters, within the loop to alter the sound while using post-effects like reverb and pitch correction for additional texture. I've also included a downloadable setup for you to try out and experiment with the techniques discussed.

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• Ripple Delay

Summary #

Maybe you don't watch the video, here are some important takeaways:

In this video, I delve into the fascinating world of creating feedback loops within Bitwig Studio's grid environment. Previously, I briefly mentioned this concept, and now I aim to offer a more extensive exploration. To start, I set up a noise source, opting for a stereo white noise, and pair it with a short envelope to generate an initial noise burst. This signal is then routed into a long delay, where I specify the delay time in milliseconds. A crucial component of this setup is the gain knob, which allows us to adjust the signal's loudness before blending it with the long delay's output. The blending process helps create a small feedback loop.

For the signal's output, I make sure to include an audio output module, ensuring we can hear the results. Importantly, I introduce a peak limiter in the effects box to protect our ears from excessive loudness caused by the feedback loop's instability. Setting it to reduce the input by about 4 dB serves as a safety measure.

The goal is to find a sweet spot where the blend between the dry sound and the feedback sounds alive but not overwhelming. Achieving this balance is often a challenge; it requires precise adjustment of the gain knob since even a minor change can lead to drastic differences in sound intensity.

To address these fluctuations, I propose incorporating an auto-gain or auto-level mechanism. By using a follower module to monitor the delay's output, I can dynamically adjust the feedback loop's gain to ensure a stable sound level. This involves some setup, including a bias and division module, which combined, create the auto-gain function.

Once the auto-gain is in place, I explore how changing the delay time affects the pitch due to alterations in the signal’s wavelength. The system responds within the constraints of my audio block size settings— set at 5.33 milliseconds for optimal pitch variation. Smaller block sizes allow for finer control over pitch, while larger ones may lead to coarser adjustments.

Furthermore, I experiment with incorporating various effects within the feedback loop itself. For instance, I add a phaser, where low speed settings prevent rapid modulation that could disrupt the sound. Adjusting the phaser allows for interesting transformations in the feedback loop's timbre.

To manage the build-up of frequencies, particularly in the low end, I apply high-pass and low-pass filters. These filters are crucial for sculpting the loop's tone, preventing it from getting too bass-heavy or shrill. Adjusting the fall parameter on the auto-gain module allows for rapid response to changes in volume, enhancing the stability of the feedback loop.

Exploration continues outside the feedback loop with post-effects, such as adding reverb via Valhalla's SuperMassive plug-in for a rich ambiance. I also introduce pitch correction using a module like Chroma, which helps contain dissonance by aligning the sound to a harmonic scale.

Throughout the video, I encourage experimentation— playing with various effects, their order, and placement within the loop to discover different sound textures. Sometimes fewer effects yield a richer exploration of sound, proving that more isn't always requisite for creating intriguing auditory landscapes.

Finally, I suggest recording the output into a Bitwig sampler for future use, either directly or through its recorder module. This way, you can capture the unique sounds generated and utilize them creatively thereafter. I emphasize the importance of setting adequate audio configurations, specifically optimizing the block size, to maximize the creative potential of feedback loops in sound design.

To aid in your exploration, I've made the setup available for download. Feedback is welcome, and I encourage viewers to experiment and have fun with this technique!

Transcription #

This is what im talking about in this video. The text is transcribed by AI, so it might not be perfect. If you find any mistakes, please let me know.
You can also click on the timestamps to jump to the right part of the video, which should be helpful.

[00:00:00] So in the last video we talked about the ripple delay by process audio and at the end of the
[00:00:05] video I teased a bit what you can do inside of Bitwig Studio and today I want to show you
[00:00:11] yeah a more fleshed out idea about this how you create these kind of feedback loops inside of
[00:00:19] the grid. I made some videos about this in the past but I think because I just talked about it
[00:00:25] in the last video I want to re-fresh this idea and give you some ideas. So first up we want to use
[00:00:31] here a noise source and of course a very short envelope right so we want to create a noise first
[00:00:41] so that's the initial setup here. Maybe we want to use a stereo white noise and then we go straight
[00:00:48] into a long delay. In this long delay we use here milliseconds as a delay unit. After that we want
[00:00:57] to use a gain knob so we can change the loudness of the signal and we use a blend in front of the long
[00:01:06] delay. So now we can blend the initial sound burst here with the feedback or with the output of the
[00:01:14] long delay. So this is here now a small feedback setup right and then of course we need to use
[00:01:20] here an output audio output so we can hear actually what's what's happening. So then in the FX box we use
[00:01:28] a peak limiter. Always use a peak limiter so you don't blow your ears out right. It gets unstable pretty fast.
[00:01:36] Let's dial this down here by minus 4 dB. Okay and then we use here this is armed so we can use our midi keyboard
[00:01:44] and we can trigger then here this noise burst going into this long delay.
[00:01:48] Right so maybe increase here the loudness a bit more slowly.
[00:02:03] And then you try to find the sweet spot before the feedback goes too crazy and louder and louder and
[00:02:09] you know amplifies itself too much. And also so it's not too quiet so it dies down pretty fast right. So this is too quiet here.
[00:02:19] And this is too much. And this sweet spot here is very hard to find. It's just a few milli decibel right.
[00:02:31] And if you find the sweet spot it feels really good. But then if you make some changes here and there you
[00:02:38] change also the loudness. So you have a constant constant battle with the loudness here. So my idea
[00:02:44] yesterday was to implement actually an auto gain or auto level a small auto level in here to
[00:02:51] make sure we always have the right volume or gain for the feedback loop to not break down and to not to
[00:02:59] amplify itself too much. So we do this here by just using a follower.
[00:03:04] So I feel like this and we analyze the output here of the long delay go into the follower, rise goes down, fall goes up, maybe use RMS.
[00:03:18] Then I use a bias here so we can influence the output of the follower a bit more.
[00:03:25] And we use a division or divide module. Right. And this is also something here that goes in there, in there and then we use this here for the division. Right.
[00:03:37] So this is how it looks like. This is the auto gain. Maybe I get this different color.
[00:03:45] Maybe also here a label.
[00:03:49] Auto gain. Right. So it's still the same feedback loop. But instead of having this gain knob here, we have now this auto gain in between. That's that's the idea.
[00:04:04] Looks a bit weird, but that's how it is. OK, so now we can try this out here.
[00:04:11] Or maybe you have to put this down.
[00:04:18] So now we have the stable loop.
[00:04:20] And we can play around here with the delay times and you can see the delay time decides how, what kind of pitch we have because it decides off the, it changes the wavelength of the signal and the wavelength of the signal.
[00:04:49] Then, you know, changes the pitch.
[00:04:52] Um, but here we have inside of the audio settings, settings, audio, block size.
[00:04:58] You can see I have an sample rate or the block size is actually 5.33 milliseconds long.
[00:05:04] You can make this shorter or longer.
[00:05:06] You probably have it much bigger.
[00:05:08] I guess.
[00:05:09] Um, I use your pretty short one 5.33 because of the thing we want to do.
[00:05:17] And that's the feedback idea here.
[00:05:19] Um, but you can hear, um, that the pitch actually doesn't change below 5 milliseconds.
[00:05:26] Only when we go above 5 milliseconds, um, the pitch changes because that's the smallest delay time we have inside of the grid.
[00:05:33] So the smallest delay time is, uh, what you dial in, in the, uh, audio settings for the sample size or for the sample buffer.
[00:05:42] Okay.
[00:05:43] So let's try it out.
[00:05:44] Okay.
[00:05:45] So let's try it out.
[00:05:46] Right.
[00:05:47] So with five milliseconds, then we stay on this pitch.
[00:05:51] Until it becomes a delay.
[00:06:01] So the feedback works, uh, and, uh, now comes the interesting part because we can use now, uh, effects inside of this loop inside of the grid.
[00:06:17] So let's put this actually here so we can add some effects here.
[00:06:20] Um, so let's start here with the phaser, mix down, maybe use it in a stereo mode here.
[00:06:28] And then we, uh, just maybe how do I do this?
[00:06:34] I'll put this here and then I go there.
[00:06:38] Right.
[00:06:39] And then also in there.
[00:06:43] Yeah.
[00:06:44] Let's use it this way.
[00:06:45] Or maybe I use here a gain knob.
[00:06:48] Maybe that's better this way.
[00:06:51] Okay.
[00:06:52] So now we have here a phaser inside of this, uh, feedback loop and we can use this to alter the sound.
[00:06:59] What I like to do is to go with the speed down because it modulates here the, um, the phaser too fast when it's up here.
[00:07:06] Um, so let's see how this sounds, um, pull this up.
[00:07:32] Um, so let's go ahead and pull this up.
[00:07:33] So the phaser changes constantly here.
[00:07:51] The feedback in, um, interesting way.
[00:07:54] And, uh, because we have this auto gain here, uh, the auto gain changes the volume and it keeps the feedback going,
[00:08:01] um, which makes it very interesting for, um, sound effects or exploring sound worlds.
[00:08:07] And we always get some kind of dissonant, um, sound from this here.
[00:08:12] And the more you throw in and the more you tweak the sound here, uh, the better it gets.
[00:08:17] So something that's also nice is to throw in here a low pass and a high pass.
[00:08:23] Cause usually these kinds of feedback loops tend to build up in the low pass.
[00:08:30] build up in the low end much, much faster than in the high end, um, high pass and low pass.
[00:08:41] And with this, um, setting here or these two filters, we can choose or remove this, right?
[00:08:47] We can remove the low end from the, uh, feedback building up over time.
[00:08:52] So this sounds like this.
[00:08:53] So this sounds like this.
[00:08:55] Oh, oh, oh, oh, oh, oh, oh, oh, oh.
[00:09:25] And by the way, bringing down this fall parameter here makes the auto gain react faster to volume changes, right?
[00:09:44] That's why I'm fiddling around here with the fall time.
[00:09:49] So these filters remove here the low end or the high pass remove the low end from the feedback building up in the low end.
[00:09:55] So we get more like screechy sounds.
[00:09:58] And if you pull down high pass and cut off here the top frequencies or the high frequencies,
[00:10:05] you get more like a low end and bussy sound.
[00:10:09] Yeah, you will figure this out if you play around with this.
[00:10:13] Oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh, oh.
[00:10:23] And this is cool.
[00:10:47] But you can then also use your postFX, so after the feedback loop, right?
[00:10:52] So we bring in here a super massive for nice reverb.
[00:11:06] So we're going to go up.
[00:11:07] And when you're going to go up.
[00:11:36] And when you think it's too dissonant.
[00:11:38] You can also throw in some pitch correction plugins here.
[00:11:41] So let's say I use Chroma.
[00:11:43] Can use anything really.
[00:11:47] So I dial in here my favorite scale.
[00:11:52] So it's not that dissonant anymore.
[00:12:13] All right.
[00:12:14] That's the idea.
[00:12:14] Also interesting using shapers.
[00:12:23] So let's say I use your Chubby Chef.
[00:12:25] Minus TC and throw this in there.
[00:12:29] Maybe before the filter.
[00:12:30] Maybe after filter.
[00:12:31] Maybe for the in front of the phaser.
[00:12:34] So that's then the experimentation.
[00:12:36] Right.
[00:12:37] Where do you put the effects.
[00:12:38] And what kind of effect influences the other effects.
[00:12:41] In the feedback.
[00:12:42] And it all gives you a different sound.
[00:12:44] So that's the interesting part.
[00:12:45] Or maybe here.
[00:13:01] Maybe without Chroma.
[00:13:15] Maybe you use the chorus here.
[00:13:16] after everything.
[00:13:41] Maybe you use the chorus here.
[00:13:44] or maybe we use a very small delay time here.
[00:13:59] for the post effects.
[00:14:09] And use Chroma after the Valhalla.
[00:14:12] Right.
[00:14:13] So many ideas.
[00:14:13] Maybe a wave folder.
[00:14:27] That's a bit too crazy.
[00:14:28] But you get the idea.
[00:14:28] Right.
[00:14:28] And it's so fun because we have this auto gain in place here.
[00:14:40] and it really tries to make the sound stable.
[00:14:46] and it kind of works.
[00:14:48] and you can experiment with this.
[00:14:51] and it's so fun because we have this auto gain in place here.
[00:14:56] and it really tries to make the sound stable.
[00:14:59] and it kind of works.
[00:15:01] and you can experiment with this.
[00:15:03] and then just use another audio track here.
[00:15:05] maybe let's say output polygrid boost fx.
[00:15:10] hit record and just save everything.
[00:15:14] launch quantization off.
[00:15:18] don't need it.
[00:15:19] pre-roll.
[00:15:23] i don't need it.
[00:15:25] right.
[00:15:26] and then you.
[00:15:27] Thank you.
[00:15:57] Oh, if you don't want to use the Bitway Clip Launcher, you can also use here, what's
[00:16:12] the name, the Rolling Sampler, this one here, right, record everything into this.
[00:16:19] And sometimes you don't need to use that many effects in this feedback loop.
[00:16:49] As you can see, we have only a few and you get so much variety and so different, so many
[00:16:56] different movements in all kinds of directions, right?
[00:16:59] So more is less and maybe exchange some of these devices here for other devices.
[00:17:06] Filters that we have also here, something like, what's the name, Ripple Delay here, or Fizz,
[00:17:15] Fizz, the Fizz filter, the end.
[00:17:19] Let's try this one.
[00:17:42] Also nice, let's say all pass delay.
[00:18:10] So pretty crazy sounds.
[00:18:11] So what I do now is I put you this into the description down below so you can download it.
[00:18:18] I already also made here a different plugin.
[00:18:22] Let me just remove this here for a moment.
[00:18:29] Feedback, what's the name?
[00:18:33] And find, ah, feedback system A.
[00:18:37] Yeah, that's basically also your setup.
[00:18:40] I also disabled here some of the devices.
[00:18:42] You can enable them and then play around with it and have some fun.
[00:18:48] Just record some stuff and put it in the sampler and, yeah, just explore some sound, sound worlds with this.
[00:18:55] So just remember, go into the audio settings here, try to pull this down to the lowest possible block size for you.
[00:19:04] That works for you.
[00:19:04] Here, five milliseconds is perfectly fine.
[00:19:07] You get some interesting pitches or some high pitches.
[00:19:11] The longer or the higher the block size is, then, yeah, you lower in pitch.
[00:19:18] You have to go with delay time, right?
[00:19:20] So five milliseconds is perfectly fine.
[00:19:22] Ten milliseconds also works.
[00:19:26] Yeah.
[00:19:27] That's it.
[00:19:29] I put you this in the description below so you can download this.
[00:19:31] Let me know what you think.
[00:19:32] Leave a like, leave a subscription and have some fun.
[00:19:36] See you in the next video.
[00:19:36] Thanks for watching and bye.
[00:20:32] That's enough.