Saturator - Audio FX Bitwig Guide

Bitwig Guide | Nov 07, 2022

This video is about exploring the saturator in Bitwig Studio. Polarity explains how it applies a transfer function, represented by a yellow line, to a signal which creates harmonics and distortion. He also explains how to use the saturator to create a gate effect or to alter the tonality of a sound. He further explains how the wave shape of the saturator can be changed in the negative and the positive range, and how the loud threshold and the knee knobs affect the sound. Finally, he demonstrates the saturator on a kick drum and explains why overtones are important.

You can watch the Video on Youtube

What is a Saturator #

A saturator is a type of audio effect that is used to add harmonic distortion and warmth to audio signals. It is a form of analog emulation that simulates the behavior of analog circuitry such as tape machines, tube amplifiers, and analog consoles.

Saturators work by introducing non-linear distortion to an audio signal. This type of distortion can create additional harmonics and overtones, which can add warmth, depth, and character to a sound. Saturators can be used on a variety of audio sources, including vocals, drums, guitars, and synths.

Some saturators offer a range of parameters that can be adjusted, such as input level, drive, saturation type, and tone. These controls allow the user to fine-tune the effect to suit the desired sound. Saturators can be used subtly to add a touch of warmth and character, or more aggressively to create a distorted, overdriven sound.

What is a transfer curve ? #

Yes, many saturators have a transfer curve, which is a graph that shows how the input signal level affects the output signal level. The transfer curve represents the saturation characteristics of the saturator, and it can be used to control the amount and type of distortion that is applied to the audio signal.

The transfer curve of a saturator typically has a non-linear shape, meaning that the relationship between the input and output signal levels is not a straight line. Instead, the curve is usually curved or sigmoidal, which means that as the input level increases, the amount of distortion increases at a faster rate.

The transfer curve is controlled by the saturator's drive or input level parameter, which determines how much of the input signal is sent through the saturator. Increasing the drive or input level will push the input signal into the nonlinear range of the transfer curve, resulting in more distortion and saturation.

Some saturators also offer different types of transfer curves, such as soft-clipping or hard-clipping, which can affect the character of the distortion. Soft-clipping saturators tend to produce a smoother, more musical distortion, while hard-clipping saturators produce a more aggressive and distorted sound.

Overall, the transfer curve is an essential component of a saturator, as it allows the user to control the amount and type of distortion that is applied to the audio signal, giving them greater creative control over the final sound.

Transcription #

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[00:00.000 --> 00:05.040] I thought maybe for today's video we dive into the saturator of Bitwig Studio, because
[00:05.040 --> 00:10.360] for me and maybe also a lot of people, it's not really clear what it does exactly to the
[00:10.360 --> 00:11.360] signal.
[00:11.360 --> 00:17.300] And we try to find this out in this video and yeah, I would say let's go.
[00:17.300 --> 00:20.700] So this is how the saturator looks like in Bitwig Studio.
[00:20.700 --> 00:23.360] And at the title it says saturator destruction.
[00:23.360 --> 00:28.200] And for me also all these devices are basically just distortion devices and I mean devices
[00:28.200 --> 00:34.160] like fuzz or overdrive, tape saturation and saturation of course.
[00:34.160 --> 00:41.600] It's just creating harmonies or harmonics, not harmonies, harmonics above your root
[00:41.600 --> 00:50.160] signal and yeah, create this kind of distortion sound in a more or less the same way.
[00:50.160 --> 00:52.920] And at the bottom here it says wave shaper.
[00:52.920 --> 00:57.240] And the wave shaper is basically where you send the signal to a kind of a transfer function
[00:57.240 --> 01:00.320] which is represented here by this yellow line.
[01:00.320 --> 01:05.320] And you can alter this line and you can send the waveform or your signal onto a different
[01:05.320 --> 01:12.100] path which creates then all results in a different wave shape and this is why it's called wave
[01:12.100 --> 01:13.100] shaper.
[01:13.100 --> 01:16.440] And I can show you this here in a minute with the oscilloscope here.
[01:16.440 --> 01:21.720] You can also make this a bit bigger so you can see it pretty clearly on the screen here.
[01:21.720 --> 01:23.220] Nice.
[01:23.220 --> 01:28.880] And we have your DC offset device on the left side and DC offset device basically just creates
[01:28.880 --> 01:32.920] positive and negative values.
[01:32.920 --> 01:41.000] And if you modulate this here at audio rate it basically creates a sound and this is also
[01:41.000 --> 01:45.440] representing what your speaker cone or your membrane at your speakers are doing.
[01:45.440 --> 01:51.080] So when you have the slider here at positive range you basically move your speaker cone
[01:51.080 --> 01:55.480] or membrane out and when you're on the negative range you're moving it back in.
[01:55.480 --> 02:01.600] And if you do this pretty fast at audio rates then you create a signal.
[02:01.600 --> 02:08.960] And for this experiment you basically just used an LFO with super slow speed so we can
[02:08.960 --> 02:12.800] analyze what's happening with the signal.
[02:12.800 --> 02:19.080] And you can also see here that we have here a transfer function on the saturator and it's
[02:19.080 --> 02:20.080] basically doing nothing.
[02:20.080 --> 02:24.880] We have here just a rounded edge at the top but it's not affecting the signal at all because
[02:24.880 --> 02:28.960] it's not loud enough to reach this curve here.
[02:28.960 --> 02:38.160] So when we bring up here the signal maybe more and see then the signal is becoming a
[02:38.160 --> 02:42.560] bit flat at the top and barely notice it.
[02:42.560 --> 02:52.560] It's not that visible maybe you make this a bit slower so we can analyze it better.
[02:52.560 --> 02:59.160] You can also see here at the bottom.
[02:59.160 --> 03:06.040] So we basically change now here the yellow line, bring this down.
[03:06.040 --> 03:09.800] So all what this does is a threshold.
[03:09.800 --> 03:14.680] So we apply this curve here basically early on.
[03:14.680 --> 03:20.840] So the signal doesn't need to be that loud to be on or is affected by that.
[03:20.840 --> 03:29.640] And you can see here now our clean sine wave becomes like a rounded square wave form.
[03:29.640 --> 03:34.080] This is exactly what this line here represents.
[03:34.080 --> 03:41.800] When we go to a certain loudness or to a certain value point here we bring the wave form to
[03:41.800 --> 03:48.200] a rounded edge or to a rounded path here and then we go to a straight line.
[03:48.200 --> 03:51.480] And you can see here it's a straight line and the edges are rounded.
[03:51.480 --> 03:54.160] So that's exactly what we dialed in.
[03:54.160 --> 03:58.160] And you can see also that this is applied to the negative range.
[03:58.160 --> 04:03.160] So we have here a zero line in the middle and this is applied to the positive range
[04:03.160 --> 04:07.320] and to the negative range of the signal itself.
[04:07.320 --> 04:11.320] So when we look here at the saturate or you can see we have a display at the left side
[04:11.320 --> 04:16.480] here where we have an orange line and the yellow line and the yellow line is the positive
[04:16.480 --> 04:19.360] range and the orange line is the negative range.
[04:19.360 --> 04:22.320] But in this display we only have a yellow line.
[04:22.320 --> 04:28.320] And the reason for that is that this one, this line here is basically the negative and
[04:28.320 --> 04:33.360] the positive range at the same time displayed on the same display on the same line.
[04:33.360 --> 04:37.640] So as you can see we go now on the back in the negative range and it goes back up here
[04:37.640 --> 04:42.680] and when we go on now it's to the negative range then it goes also back up.
[04:42.680 --> 04:48.120] So it's basically positive, negative, positive, negative.
[04:48.120 --> 04:54.200] And yeah, it's pretty much hard to get in the brain how it works.
[04:54.200 --> 05:04.680] And if you look here at the graph at the left side you can see it's much easier to get.
[05:04.680 --> 05:10.920] But then again we can change how the wave shape of the saturator behaves in the negative
[05:10.920 --> 05:14.920] range differently from how it behaves in the positive range.
[05:14.920 --> 05:22.200] And we have these knobs here at the right side and it says loud threshold skew which
[05:22.200 --> 05:26.520] basically changes how the signal behaves in the negative range.
[05:26.520 --> 05:29.280] As you can see we have now here an orange line.
[05:29.280 --> 05:35.760] So we can say we want to have this transfer function happening earlier on in the negative
[05:35.760 --> 05:37.200] range than in the positive range.
[05:37.200 --> 05:41.200] And you can see it is also displayed here in the oscilloscope.
[05:41.200 --> 05:50.560] Maybe we have to wait until it moves beyond my cam here.
[05:50.560 --> 05:55.600] But you can see here the positive range is the same as before but in the negative range
[05:55.600 --> 06:01.560] we break earlier onto a straight line than in the positive range.
[06:01.560 --> 06:06.200] So you can alter how the saturator behaves in the negative range than in the positive
[06:06.200 --> 06:07.200] range.
[06:07.200 --> 06:15.280] You can also change here the knee which makes the breakdown even harder.
[06:15.280 --> 06:19.920] And you can see it changes the positive and the negative range at the same time.
[06:19.920 --> 06:27.200] So these knobs are basically only knobs to dial in the difference what you want to have
[06:27.200 --> 06:29.880] different in the negative range than in the positive range.
[06:29.880 --> 06:34.640] There are not kind of absolute values you can dial in.
[06:34.640 --> 06:40.960] It's relative to what you dialed in on these big knobs here.
[06:40.960 --> 06:48.880] Then we have here also this one here where we can kind of go back to negative.
[06:48.880 --> 06:55.320] And this is called, I think maybe write it in the comments if I'm wrong here, but this
[06:55.320 --> 07:03.320] is called folding because, maybe go back here to this.
[07:03.320 --> 07:08.120] Because you can see it already here on the graph, you take the signal above this line
[07:08.120 --> 07:13.360] or above this point, maybe I freeze this down here, above this point here.
[07:13.360 --> 07:19.880] And instead of letting the signal pass and go into a nice arc here back to this point,
[07:19.880 --> 07:22.480] you fold it back onto itself.
[07:22.480 --> 07:35.040] It's like a piece of paper, it's like a piece of paper like this one here.
[07:35.040 --> 07:42.040] And then you take the edge and fold it back onto itself like this, this is why it's called
[07:42.040 --> 07:46.080] folding more or less.
[07:46.080 --> 07:50.000] Instead of having this waveform, this edgy thing here peeking out, you bring it back
[07:50.000 --> 07:52.200] down to this.
[07:52.200 --> 07:58.960] And this is also why it's called wave folding.
[07:58.960 --> 08:06.040] Okay, so we have this and we can also change of course how it behaves maybe in the negative
[08:06.040 --> 08:07.040] range.
[08:07.040 --> 08:11.720] So we have folding at the positive range and we have no folding at the negative range,
[08:11.720 --> 08:16.000] maybe remove the freeze here.
[08:16.000 --> 08:21.880] So now we should see this folding only happening down here and at the top, it should be pretty
[08:21.880 --> 08:24.880] fine.
[08:24.880 --> 08:30.240] It's exactly opposite now, okay.
[08:30.240 --> 08:42.320] Maybe put it this way.
[08:42.320 --> 08:53.440] Oh yeah, now we have the folding at the orange part here, which is down here.
[08:53.440 --> 08:59.040] And at the top, we have still the rounded sine wave letting completely pass without
[08:59.040 --> 09:01.400] alteration.
[09:01.400 --> 09:10.400] Okay, that's basically the simple explanation for this graph here.
[09:10.400 --> 09:14.720] There's also these three knobs here, which is called quiet.
[09:14.720 --> 09:23.400] And this is called quiet because it only applies to this bottom area here.
[09:23.400 --> 09:28.800] And the bottom area are basically all the values below a certain point.
[09:28.800 --> 09:35.880] And if we look at here at this graph here at the top, we basically just apply changes
[09:35.880 --> 09:40.200] to this area here around the zero line, so the quiet parts.
[09:40.200 --> 09:50.360] And if you do stuff like this here, you maybe something like this, it's almost like you create
[09:50.360 --> 09:58.280] a gate, a noise gate, where you filter out everything, or you instead of letting here
[09:58.280 --> 10:05.880] the signals die out slowly and letting it die out into the quietness, you bring it straight
[10:05.880 --> 10:14.240] down to zero, which then results in a gate effect or you remove the signal completely
[10:14.240 --> 10:15.600] in an instant.
[10:15.600 --> 10:21.560] So maybe we use some real sounds and try out how this works in the real life.
[10:21.560 --> 10:30.440] So for instance, I could use here a Polysynth, and the Polysynth has some noise,
[10:30.440 --> 10:34.440] and it can show you how this works with the gate I just explained here, maybe get rid
[10:34.440 --> 10:38.840] of here some, just these parts.
[10:38.840 --> 10:42.080] Okay, so we have noise dealt in.
[10:42.080 --> 11:06.800] I can hear, can remove the noise completely.
[11:06.800 --> 11:16.280] Just using all these, everything that's below this point is basically completely muted.
[11:16.280 --> 11:25.040] And this is nice when you have maybe some drums, maybe let's see if I can find you some
[11:25.040 --> 11:26.040] real drums.
[11:26.040 --> 11:30.800] Oh yeah, this is nice.
[11:30.800 --> 11:48.240] So, let's switch this to an audio track, okay, can you hear it?
[11:48.240 --> 12:12.560] Yeah, I can completely remove some of the tails of the drums.
[12:12.560 --> 12:36.880] But it also introduces some kind of noise at the edge here probably.
[12:36.880 --> 12:42.960] And sometimes this is also nice on bass sounds, where you have a big fat bass sound, and
[12:42.960 --> 12:49.520] you have reverb on it, and you want to cut out the reverb, but also want to have distortion
[12:49.520 --> 12:53.160] so you can basically do it in one step.
[12:53.160 --> 12:56.760] And maybe you can show you this here in a minute.
[12:56.760 --> 13:21.760] So maybe we use a phase four, make some bass, okay, and then you put reverb on it.
[13:21.760 --> 13:28.080] And then you use the saturation device.
[13:28.080 --> 13:44.040] And then you see a hard, hard cut.
[13:44.040 --> 14:03.440] And then you can remove some of these reverb sounds.
[14:03.440 --> 14:11.240] And the difference here is when you remove this, slowly dying out, and here you can cut
[14:11.240 --> 14:18.360] it off.
[14:18.360 --> 14:24.360] So it's kind of an gate effect, and in distortion or overdrive effect at the same time.
[14:24.360 --> 14:28.320] So this is pretty handy sometimes.
[14:28.320 --> 14:36.640] And of course, is when you use drums, like we did here, use the real drums.
[14:36.640 --> 14:55.400] And instead of gating, we can also apply here nice rounded edge at the top.
[14:55.400 --> 15:00.920] You can see when I use here to drive, I basically raise the input volume of the signal going
[15:00.920 --> 15:02.840] into the saturator.
[15:02.840 --> 15:17.600] And it changes here also the curve because the scaling of the curve is a bit different.
[15:17.600 --> 15:21.920] Because if you make it louder, then of course, this curve here is in a different scale to
[15:21.920 --> 15:23.520] the input signal.
[15:23.520 --> 15:28.720] And we can also see here that when you have this linked on, the saturator tries to compensate
[15:28.720 --> 15:31.000] for your input gain on the output.
[15:31.000 --> 16:00.920] So when you basically raise the input, you lower the output.
[16:00.920 --> 16:10.120] Okay so speaking about harmonics, I have here a test tone, which creates a clean sine wave.
[16:10.120 --> 16:13.920] So there are no harmonics, it's just one frequency.
[16:13.920 --> 16:19.000] And when we bring in here the saturator, you can see here the white line is at this position
[16:19.000 --> 16:20.000] here.
[16:20.000 --> 16:22.800] When we change the gain of the test tone, we can change the white line.
[16:22.800 --> 16:33.000] We can also use here the drive to raise the input signal.
[16:33.000 --> 16:41.080] Maybe bring this bit down here, make a hard knee.
[16:41.080 --> 16:56.520] And then we kind of create harmonics from this single sine shape here.
[16:56.520 --> 17:01.720] You can also see the odd and even harmonics changing differently.
[17:01.720 --> 17:11.800] We have also here the slow pass filter, which is only applied to the saturated signal.
[17:11.800 --> 17:18.280] We can tame the overtones or the other harmonics a bit here, bring them down.
[17:18.280 --> 17:23.200] And there's also that you can change the filter type.
[17:23.200 --> 17:33.680] And I would advise you to click to select the device, hit F1, then look at the modes
[17:33.680 --> 17:34.680] here.
[17:34.680 --> 17:38.280] And you can see the steepness, pole count of the low pass filter, G mode are gentler
[17:38.280 --> 17:40.240] and R modes are a bit bumpier.
[17:40.240 --> 17:47.360] You can try out different settings here for the low pass filter and play around a bit
[17:47.360 --> 17:52.840] and find the sweet spot for your current sound.
[17:52.840 --> 17:57.240] But in general, you create overtones and you have to be aware of it.
[17:57.240 --> 18:02.120] And sometimes when you have a super clean sound like a bass drum and it sounds alone
[18:02.120 --> 18:09.000] and not that fat, then you use an insaturator, it creates overtones and then you have this
[18:09.000 --> 18:12.080] much, much richer sound in the end.
[18:12.080 --> 18:17.520] Maybe I can use your kick drum, show you this maybe.
[18:17.520 --> 18:46.960] Kick, e kick, so let's remove this, loop this.
[18:46.960 --> 19:00.000] So nothing happens to the kick sound, it's like a sine wave hitting just one frequency
[19:00.000 --> 19:06.560] more or less.
[19:06.560 --> 19:24.000] And then you add harmonics with the saturator, it sounds more fat and present.
[19:24.000 --> 19:49.720] So you can completely change the tonality of your kick drum, make it more fat and if you
[19:49.720 --> 19:57.640] think about listening to kick drums on small speakers or ear buds or headphones, you need
[19:57.640 --> 20:02.800] these overtones to make the listener aware that there is actually a kick drum somewhere
[20:02.800 --> 20:09.400] in your mixdown and also on bigger speakers, it's much, much better to have some of the
[20:09.400 --> 20:15.280] harmonics to make the brain notice that there is something below there.
[20:15.280 --> 20:21.800] So that's basically my version of how the saturator works or how I think it works.
[20:21.800 --> 20:27.520] And you can still see I'm mostly a musician, not a technician, also not a developer, so
[20:27.520 --> 20:30.480] I try to explain it in simple words.
[20:30.480 --> 20:36.280] If you have some questions about it or maybe some corrections, then please leave it in
[20:36.280 --> 20:41.160] the comments, also leave a like if you liked the video and if you want to stay up to date
[20:41.160 --> 20:47.240] then please subscribe to the channel and if you have some hints maybe at what I can do
[20:47.240 --> 20:55.560] next, video wise or maybe tutorials for, then also leave me some comments, it's always helpful.
[20:55.560 --> 21:13.000] So thanks for watching and I'll see you in the next video, bye.