Tags: posts polarity-music Bitwig Mixing Tutorial Modulators

This Will Finally Let You Control Your Bass Harmonics

Tutorial | Oct 21, 2025

In this Bitwig tutorial, I demonstrate how to use key tracking with EQ5 to dynamically shape harmonics of bass sounds in response to changing notes, a technique not easily achievable with most VST plugins. I also show how to use key tracking and sidechaining to remove clashing frequencies between instruments, all within Bitwig’s flexible modulation system. These methods allow for deep and musical control over your sound design, and presets are available for download on my GitHub.

You can watch the Video on Youtube

Short Overview

Recently, I've been using a really simple but powerful technique in Bitwig that lets me key track EQ bands to follow the notes I'm playing. This allows me to target and shape specific harmonics of a bass or instrument sound as the notes change, something that isn't easily possible in most VST plugins. I often use it to carve out or boost certain frequencies directly on instruments, making the EQ feel like part of the instrument itself. It's especially useful for adjusting harmonics or avoiding clashes between bass and lead sounds, and I've even shared presets for this on my Github for anyone interested.

Introduction

In this video, I want to show you a technique in Bitwig that I use frequently, especially recently. It is something very powerful and unique to Bitwig, not easily achievable in most VST plugins unless you use specialized tools. The focus is on manipulating harmonics of a bass sound dynamically, in sync with the notes you play, using key tracking within Bitwig’s EQ devices.

Overview of the Bass Harmonics Problem

When working with basslines, the fundamental and its harmonics (second, third, etc.) move up and down the frequency spectrum as different notes are played. Sometimes, I want to adjust or even subtract specific harmonics, such as boosting the third harmonic or cutting the second, but since the note changes, the harmonic frequencies also shift. In most VST plugins, it's hard to set an EQ band to follow this movement automatically.

Using EQ Key Tracking in Bitwig

Bitwig offers a solution through key tracking modulation, allowing EQ bands to follow notes played by your instrument. Here’s how I set it up:

Setting Up the EQ

I start by inserting EQ5 on the bass channel. To better visualize the frequencies, I set the EQ’s analyzer resolution to huge and speed to fast. This helps me clearly see the fundamental (sub), second harmonic, third harmonic, and so on.

The Key Track Plus Modulator

I use the Key Track Plus modulator. You can technically modulate the global shift of the EQ, but this doesn’t display the modulation range visually, so I prefer to modulate each band’s frequency parameter individually.

Calibrating the Key Tracking

To make sure the tracking is accurate, I follow Bitwig’s documentation:

This way, whenever I play different notes, the EQ bands follow the fundamentals and their harmonics perfectly.

Adjusting Q Factor

I use a high Q factor (around 10) for precision, allowing very narrow boosts or cuts to specific harmonics. By targeting only key harmonics, I can transform the timbre or suppress troublesome overtones.

Making and Sharing Presets

Because I use this so frequently, I created a preset called "key tracked partials." It allows control over several harmonics directly (up to the fifth partial), and I’ve shared this preset for free on my GitHub for others to download.

Applications: Sound Design and Mix Clarity

This trick is most useful directly on an instrument channel, especially if the sound is monophonic, which is common for bass. It lets you reshape the harmonic content in a very musical and dynamic way. For example, if the bass and a lead instrument clash in overtones, I can dynamically attenuate just the specific overtone from the bass.

Dynamic Sidechained Frequency Notching

Another useful trick is dynamically creating a notch in the bass wherever the lead line is playing. This is how I do it:

  1. Place Filter+ or another notch-capable device on the bass.
  2. Use the Key Track modulator and set up a Note Receiver to follow the lead line’s notes.
  3. Modulate the notch filter frequency using 60 semitones to line up with the lead notes.
  4. Add an audio sidechain modulator to control the mix amount of the notch based on the lead's audio presence.
  5. This creates a moving notch that follows the lead’s notes and only activates when the lead is actually producing sound, helping de-clutter the mix where the lead and bass overlap.

Limitations and Polyphony

If you need this system to work polyphonically (multiple lead notes at once), things get tricky. You can use multiple voices in Filter+ for some limited polyphonic tracking, but it quickly becomes complicated and less precise, especially since most filters are not designed for this kind of spectral precision. This monophonic limitation means the trick is best for bass-lead relationships or other simple scenarios.

Practical Considerations

There are specialized spectral processors you might use for more complicated or polyphonic material. However, Bitwig’s modulator and key tracking features provide a powerful and flexible solution if you are working with note-based instruments, especially in environments such as Linux or mobile where few advanced plugins are available.

Conclusion

Bitwig’s modulators, particularly Key Track Plus, make it straightforward to craft dynamic EQ movements that follow your music, enabling creative control over harmonic content that is not possible in most VSTs. I use this constantly to carve space and enhance sounds, and I encourage others to try these techniques, especially as I’ve provided the preset for easy download on my GitHub.

If you found this useful, remember to support my work, explore my presets, and experiment with these modulation tricks yourself.

Full Video Transcription

This is what im talking about in this video. The text is transcribed by Whisper, 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.

Click to expand Transcription

[00:00:00] Hey folks, I want to show you something in Bitwig that I do all the time recently at least.
[00:00:05] And it's very simple to do and it's not really possible, but most VST plug-ins.
[00:00:10] Maybe there are some specialized plug-ins for that, but yeah, as far as I know, it's not
[00:00:15] easy to do. So here in Bitwig we have some kind of drum bass tune. I show you how it sounds.
[00:00:30] And of course there is some kind of bass sound in here and you can see the sub, then the second
[00:00:45] harmonic, the third harmonic, the fourth harmonic and so on. And sometimes you want to change that,
[00:00:51] you want to change the second harmonic all the time, right, or the third harmonic. But the problem
[00:00:57] is we play actually here a bass pattern, so with different notes, right? So when the notes change,
[00:01:03] also all the frequencies change for the fundamental, for the second harmonic, for the third harmonic,
[00:01:09] and so on. So what we can do now in Bitwig is we can just use key tracking for the EQ,
[00:01:15] which is very powerful, in my opinion, and it's not easy to do in most VST plug-ins. So here in
[00:01:21] Procure 4, as far as I know, it's not possible to key track. You can use here down the piano
[00:01:28] roll to pinpoint certain frequencies, but you can't make it so it changes with the
[00:01:35] notes that come into the plug-in. Maybe it's possible. Let me know in the comments down below.
[00:01:39] So what I do most of the time is here in Bitwig, I just use an EQ5 for that.
[00:01:49] And maybe we also want to switch this here, the resolution to huge and speed too fast, okay.
[00:01:55] So now we can see here the root or the sub, the second harmonic, the third harmonic, and so on.
[00:02:04] And sometimes you, like I said, you want to change it specifically so the sound changes. Maybe it's
[00:02:09] not something you want to do on the bass or on the master, but on an instrument you maybe want to do
[00:02:15] it. So here what I do is I just use the key track modulator, key track plus, that's what I want to
[00:02:25] use. And then you can modulate here either the shift, the global shift, but the downside of this
[00:02:31] is that you actually can't see the modulation in here. So if you modulate this, you don't see the
[00:02:36] blue dots. So what I do then is I just modulate here this individually. So here the first
[00:02:43] band, then the second band and the third band. And I click here on the modulator on the left side
[00:02:50] that type in 60, 60 and 60. So the question now is why 60, right? So when you highlight here the
[00:03:02] modulator and you pull up the help, it says the default curve works one-to-one key tracking
[00:03:09] for the broad frequency controls, the frequency parameter on the filter on the test tone device,
[00:03:14] it says set the parameter to C3 and then set the modulation amount to 60 semitones. So that's
[00:03:21] basically the range here of the key track modulator. So what we want to do now is we want to set
[00:03:26] the first band to C3 and to modulate it here this by 60. So perfect. The second harmonic is actually
[00:03:35] double the frequency of the first harmonic or the fundamental here. And you can just say this is
[00:03:43] C4. This is C3 and this is C4. So just one octave and one octave means it's doubled the frequency.
[00:03:52] So that's why I type in C4. Then we have here the third harmonic and the third harmonic is that's
[00:03:59] what I know from the top of my head is G4. So this is basically three times the frequency of
[00:04:07] 262 hertz, right? And then if you want to have the fourth partially here, you just use 262 times
[00:04:17] four and then you type in here the hertz. So anyway, I just want to use here the first three
[00:04:24] partials. So now we can use a very narrow Q factor here, maybe 10. Also here 10.
[00:04:35] Now we can target basically all of these partials directly. You can say we want to take out the sub,
[00:04:46] right? And you can see when the note changes, it also changes here the
[00:04:51] frequencies, of course. So second harmonic, third, or you can boost it if you want to.
[00:05:15] And that's very powerful when you want to change the sound of a bass sound on the instrument directly
[00:05:21] because with this the EQ becomes part of the instrument and most of the times bass sounds
[00:05:29] are monophonic and the EQ is monophonic. So it's not a big problem. And I do this all the time
[00:05:37] because I sometimes just want to take out here the second partial of the bass sound.
[00:05:44] So I also made your preset for this called key tracked partials and I put this here on to my
[00:05:49] github so you can download this for free if you want to. And then we have here also the second,
[00:05:56] the third, the fourth, and the fifth if you want to change that.
[00:06:11] You can completely change how the bass sounds with this. So that's what it makes it so powerful.
[00:06:23] So yeah, that's what I want to show you because I do this all the time recently on most of my
[00:06:53] drum bass tunes just to change the content or the frequency content of certain bass sounds
[00:07:01] and it's very powerful in my opinion. Another problem sometimes is here when you have a bass
[00:07:08] sound and some of the bass sound or the overtones of the bass sound clash actually with the lead
[00:07:13] sound. So for instance here this sound. So what you want to do is you want to EQ out some of these
[00:07:34] sounds or the fundamental of this lead sound from the bass and you usually need some kind of
[00:07:41] spectral processor for that. But if you just want to keep it simple, all you need to do is to
[00:07:48] actually use a filter plus here. Sometimes I do this. It's not something I do all the time but
[00:07:59] sometimes it just does the job. So we don't need here the transfer curve or the
[00:08:05] the distortion device. We just want to use here the notch filter. Let's use an EQ, what's the name,
[00:08:14] EQ analyzer, EQ curve analyzer. Okay, put this over there. So you can see here this
[00:08:24] notch filter looks like this. And then you use the mix knob, pull the mix out. It's more or less
[00:08:33] like an EQ dip. So we can completely remove the frequency or we just slightly remove it or not
[00:08:41] at all. So what we can do now is we can use a key track here for this. Key track modulator.
[00:08:51] That's cool. And here we use a receiver, a note receiver, and we just pull down or pull in here
[00:09:02] the notes from the lead or music lead. Maybe after quantize. Okay, so then
[00:09:12] you can see we receive here the notes from the lead channel or from the lead instrument.
[00:09:25] And we can use this then here to change the frequency of this notch filter. We use also here 60,
[00:09:33] exactly 60, nice. So now we have more or less the right frequency. But sometimes when you release
[00:09:42] the note or when you just play a note and you release the note, you have some kind of release
[00:09:48] time, maybe reverb on it or something like this. So you don't want to go completely out with the
[00:09:54] filter at the moment you release the key. So you want to focus on the sound itself. So what we can
[00:10:02] do with this is we can use a sidechain modulator here, audio sidechain. And we also bring in here
[00:10:12] from the music, the lead sound, use the post. So we receive basically the audio signal here.
[00:10:21] We can focus on this.
[00:10:23] And the more sound we have, the more we want to dial in here, actually the
[00:10:38] notch filter. And you can see this here, maybe we amplify this a bit more.
[00:10:55] So we have a notch filter that moves around on the frequency spectrum based on this lead instrument
[00:11:05] here. Of course, it's very important that you don't change your actually the ratio of the synth
[00:11:12] itself, right? Or you pitch it up inside the synthesizer. You need to stay true to the key.
[00:11:18] So when you play C3, the instrument should play C3. Or it doesn't make any sense.
[00:11:24] That's very important to know. So now that we have this in here, we can basically use the audio
[00:11:32] sidechain to modify how much we want to dial in the notch filter. We can also exchange this here
[00:11:40] for different notch filter. I think there's a different one, maybe the XP here as a notch filter.
[00:11:47] Yeah, that's not looking good. So we go back to SVF.
[00:11:59] You can make something like this if you want to have it polyphonically. So when you play chords
[00:12:06] and you want to take all of these notes from the chords and you want to reduce or remove it from
[00:12:11] the frequency spectrum, you can't do this with the notch filter. You have to switch this then
[00:12:18] to a bandpass filter. It looks like this then. Maybe a steepo one. Let's use your selling key.
[00:12:26] Maybe dial it in here for a moment.
[00:12:35] And then you have to put this to 50% and then at the postfx you can use tool devices. So it gets
[00:12:48] complicated. It's probably not something we want to do.
[00:12:51] Maybe we modulate instead of this here. We go to 50%,
[00:12:59] pull this down and use this here.
[00:13:03] And then used on the filter plus we can use here then voices. We can say we want to use
[00:13:17] 12 voices. We can use up to 12 notes. So maybe
[00:13:26] use two. As you can see, we have now two notches here because we are using two notes.
[00:13:35] So it's more or less like a spectral reducing sidechain plug-in. But the downside is it only
[00:13:44] works with notes. So if you don't have notes, if you just use audio material, it's not going to
[00:13:50] work because you need to pitch track and then you have a lot of latency and it's not correct all the
[00:13:55] time. But if you just use notes, you can just receive the notes here on a different channel,
[00:14:02] change the offset to certain filters and then use an audio sidechain to actually change the
[00:14:10] amount, how much you want to dial it in or change the amplitude of that. So here the second one,
[00:14:17] the polyphonic thing, I wouldn't use that. You can try it out, but most of the times the filter
[00:14:23] is not steep enough, BPA is not steep enough and it's experimental, I would say. But sometimes
[00:14:30] just monophonic material and you have a lead sound and you want to reduce the lead sound or the
[00:14:35] frequencies from the lead sound from a different channel. This is okay to do to try it out if you
[00:14:42] don't have any other plug-ins. Sometimes you are using linux and you can't use any specifically
[00:14:50] designed plug-ins for that because it's iLog or whatever you are, you are on a trip or on mobile
[00:14:56] or whatever. So you can do these kind of tricks here in Bitwig very easily just with this setup.
[00:15:04] Maybe let me remove this here for a moment. This is actually a notch, no, SVF notch.
[00:15:11] Yeah, it kind of works. Then of course we have to reduce, remove here the
[00:15:33] EQ curve analyzer, this one.
[00:15:37] And then it does its job.
[00:16:00] Yeah, sometimes this is what I do. It's not perfect, but it's just sometimes it's enough
[00:16:06] just to reduce certain frequencies on a different track and it works. In Bitwig at least very simply
[00:16:13] just by using a two modulators and the other trick with the EQ. Five years also very neat to do
[00:16:19] and I put you this preset here on my Github so you can just download this and have some fun.
[00:16:26] Okay, that's it for now. Thanks for watching. Leave me a like if you like the video. If you
[00:16:31] don't like it then also leave me a like of course. Leave a subscription. Subscribe to my Patreon if
[00:16:37] you want to. If you don't want to then okay, I guess. See you in the next video. Thanks for watching. Bye.
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