How to Make Complextro Bass in Serum

What Is Complextro?

Complextro is one of the most technically demanding styles of bass music to produce. The name says it all. Complex electro. It is characterized by rapid-fire bass sound switches, where different bass timbres alternate at high speed within a single phrase. Instead of one bass sound playing through a section, you might have four, five, or even eight different sounds trading off every beat or half-beat.

Artists like Wolfgang Gartner, Kill The Noise, and Feed Me pioneered this style, and it remains popular in bass-heavy electronic music. The challenge is not just creating individual bass sounds (though that matters) but programming them together in a way that feels musical and intentional rather than random and chaotic.

Building Your Bass Sound Library

Before you can create complextro patterns, you need a collection of contrasting bass sounds. The key word is contrast. Each sound needs to be distinctly different from the others so the rapid switching creates interesting textural variety.

Sound Categories

Build at least one sound from each of these categories. A growl bass using wavetable modulation with an LFO on the wavetable position and heavy distortion. A pluck bass with a fast envelope on the filter cutoff, short decay, and no sustain. A wobble bass with an LFO on the filter at 1/4 or 1/8 rate. A buzz bass using FM synthesis with a square wave modulator and moderate FM depth. And a clean sub bass with a pure sine wave for contrast and weight.

Each sound should occupy a similar frequency range (roughly 80-500Hz for the fundamental) so they all feel balanced when switching between them. If one sound is much louder or bassier than the others, the switches will sound uneven.

Creating Sounds in Serum

For the growl, load a complex wavetable into OSC A (try the “Monster” or “Growl” tables). Set an LFO on the wavetable position at a moderate rate. Add distortion in the FX chain and a band-pass filter. This gives you a sound with aggressive character and movement.

For the pluck, use a saw wave with 4 unison voices. Set a tight envelope (zero attack, 150ms decay, zero sustain) on a low-pass filter. The filter opens quickly and closes, creating a percussive hit with harmonic content. Add a touch of reverb for depth.

For the buzz, enable FM synthesis from OSC B to OSC A. Use a square wave in OSC B and a sine in OSC A. Moderate FM amount (30-50%). The square wave modulator creates the buzzy, digital character. Add a high-pass filter at 80Hz to keep it clean.

Programming Complextro Patterns

The magic of complextro is in the MIDI programming. You need to carefully choreograph which sound plays when, creating patterns that have rhythmic logic and musical flow despite the rapid switching.

Track Layout

Set up each bass sound on its own track in your DAW. This gives you independent control over the volume, processing, and MIDI of each sound. Write your MIDI patterns so that only one bass sound plays at any given time. No overlapping notes between tracks.

A simple starting pattern might alternate between two sounds every beat for 4 bars. Then introduce a third sound in bars 5-8. By bars 9-16, you might be switching between all five sounds in a complex, syncopated pattern. Start simple and build complexity gradually.

Rhythmic Patterns

Complextro bass patterns work best when they have an underlying rhythmic logic. Try programming your switches on the 16th note grid. Common patterns include alternating on every 8th note, alternating on every 16th note (more frantic), or groups of two 16th notes per sound (creating a pair-switching feel).

Leave gaps. Not every 16th note needs to have a bass sound playing. Strategic silence creates contrast and lets the drums punch through. A gap followed by a new bass sound creates a staccato, punchy feel that drives the rhythm forward.

Making It Sound Musical

Pitch Consistency

Keep all your bass sounds on the same root note (or at least the same key). Switching between sounds is disorienting enough without also jumping between random pitches. The root note provides an anchor that ties all the different timbres together. Occasional pitch movement (like dropping to the fifth or octave) can work at specific moments for emphasis.

Volume and Processing Balance

Level-match all your bass sounds carefully. When switching rapidly between them, any volume differences will be very obvious. Use a VU meter or LUFS meter to ensure all sounds hit at approximately the same perceived loudness. Also match the low-end weight of each sound. If one has a massive sub and another has none, the switching will feel unbalanced.

Glue Processing

Route all your bass tracks to a single bus and apply shared processing. A bus compressor, gentle saturation, and a consistent EQ shape help the different sounds feel like they belong together. Without bus processing, complextro can sound like a collection of random sounds. With it, the sounds feel like variations of one instrument.

Arrangement Considerations

Complextro works best in short bursts. Full sections of maximum complexity can be exhausting to listen to. Use the most complex switching patterns in your drops and choruses, then pull back to simpler bass patterns (or even a single sustained bass sound) during verses and breakdowns. This contrast makes the complex sections more impactful.

Consider gradually increasing the complexity through your arrangement. Start with two-sound switching, then three, then four. By the final drop, pull out all the stops with your most complex pattern. This creates a satisfying sense of escalation through the track.

Having a library of quality Serum presets gives you more sounds to work with and speeds up the sound design phase so you can focus on the programming.

Start Building Complextro Patterns

Complextro is challenging but incredibly rewarding to produce. The key is starting simple, building contrast between your sounds, and programming with rhythmic intention. With practice, you will develop an instinct for which sounds work together and how to arrange the switches for maximum impact.

Get a head start with the Free Serum Taster Pack for some contrasting bass sounds to practice with. Then check out the Preset Drive collection for a wider palette of production-ready bass presets.