Dubstep wobble bass is produced by an LFO modulating a synth's volume, filter cutoff, or distortion

The ‘wobble bass’ (also called the ‘wub’) is a sustained bass note manipulated rhythmically by a low-frequency oscillator (LFO) to create a pulsing, undulating timbre. The LFO modulates one or more synth parameters: typically amplitude/volume (making the bass pulse in and out), filter cutoff (creating a vowel-like formant sweep), or distortion amount (adding grit on peaks). The LFO rate determines wobble speed; set it to an eighth-note or sixteenth-note grid subdivision to lock to the groove. The resulting timbre is ‘punctuated by rhythmic variations in volume, filter cutoff, or distortion.’ This mechanism is central to the club-friendly branch of dubstep.

Examples

In any synth: (1) route LFO to filter cutoff; (2) set LFO rate to a rhythmic subdivision (at 140 BPM: 1/8 note = ~2.33 Hz); (3) use a sustained note with slow synth attack; (4) open and close filter with LFO depth. Vary between filter, amplitude, and distortion targets to shape character.

Assessment

Describe the three synth parameters most commonly modulated by the LFO in wobble bass production. Demonstrate by building a wobble bass patch and changing LFO rate to show how it affects groove feel.