Serum, by Xfer Records, made wavetable synthesis visual and fast, and became one of the most used synths in electronic music. Its interface shows you the waveform changing as you work, and its drag-and-drop modulation makes complex movement quick to set up. Serum 2 extends the original with more oscillators and oscillator types; the core wavetable workflow is the same.
Wavetable oscillators
A wavetable is a series of single-cycle waveforms. Serum's main oscillators play a chosen frame of the table:
- Wavetable position - which frame plays. Moving it morphs the timbre.
- Octave, semitone and fine tuning.
- Phase and random phase - consistent starts for punchy basses, random starts for wide pads.
Warp modes
Each oscillator has warp modes that distort the waveform further - sync, bend, PWM, asymmetric, mirror, FM and remap among them. They add harmonic movement on top of position changes.
Unison
Stack multiple detuned voices for width and size. Huge for leads and pads. Keep basses narrow or mono, and use the sub oscillator for a solid low end.
Sub and noise oscillators
- Sub oscillator - a simple waveform an octave or two below, for weight.
- Noise oscillator - a library of noise and texture samples for air, attack and grit.
Filter
Serum's filter offers many types - classic low-pass, high-pass and band-pass, plus combs, formant and more experimental filters - with drive and mix controls.
Modulation
Drag a modulation source - an envelope, an LFO, velocity, the mod wheel - onto any parameter to assign it. Serum's LFOs can be drawn freely, which makes rhythmic and complex shapes easy.
- Envelope to wavetable position - timbre changes at the start of each note.
- Tempo-synced LFO to position and cutoff - moving, growling basses.
- Drawn LFO shapes - rhythmic gating and stepped movement.
Making your own wavetables
Serum can import audio and turn it into a wavetable - a voice, a field recording, a chord, a drum loop - and lets you draw waveforms or generate them from formulas. Your own tables make your sounds unique.
Effects
Serum's built-in effects rack - distortion, compression, EQ, chorus, delay, reverb and more - lets you finish a sound inside the synth. Distortion and compression after the filter are central to modern bass design.
A modern bass recipe
- One wavetable oscillator with a harmonically rich table, unison off.
- Sub oscillator on, mono.
- Low-pass filter with drive.
- Tempo-synced LFO (1/8 or 1/4) on wavetable position and filter cutoff.
- Distortion, then compression, then EQ in the effects rack.
- Automate the LFO rate for variation.
Do this now
- Build the bass recipe and write an eight-bar pattern with it.
- Import a short vocal phrase as a wavetable and design a pad from it.
- Draw a custom LFO shape and use it to gate a chord.