A wobble bass is an LFO moving a lowpass filter’s cutoff in time with the track. That’s it. One modulation route built an entire genre, and it’s still the first thing I teach anyone starting sound design in Serum 2.
The basics take two minutes. The difference between a beginner wobble and a usable one is in three settings people ignore: the LFO shape, the retrigger mode, and what happens to the sub.
The two-minute wobble
- Init a patch, set oscillator A to a saw. Add a bit of unison if you want thickness, but start with one voice.
- Drop it an octave, add a lowpass filter, cutoff around 200 Hz.
- Drag LFO 1 onto cutoff with a healthy amount, enough that the filter sweeps from dark to bright.
- Set the LFO to tempo sync, rate 1/4.
- Hold a low note. It wobbles.
Now change the rate: 1/4 is the slow dubstep lurch, 1/8 is the classic mid-tempo wub, 1/16 gets you talking-speed. Automate the rate across a phrase, 1/4 into 1/8 into 1/16, and you have the standard build pattern every dubstep drop used for a decade.
LFO shape decides the character
This is the detail that separates presets from init patches. A plain sine or triangle wobble sounds polite. What helps:
- Bend the LFO curve so the rise is slower than the fall. The filter opens with a swell and snaps shut. Instantly more vocal.
- Add a small step or notch in the middle of the shape for a stutter inside each wub.
- Don’t run the LFO across the filter’s full range. Map it to sweep from around 150 Hz up to 1–2 kHz. Full-range sweeps spend half their time in useless territory above 5 kHz.
Custom LFO shapes are the real reason Serum took over bass music. Two minutes of drawing beats an hour of automation.
Retrigger: note-on vs free-running
The LFO trigger mode changes the groove more than the rate does.
Retriggered on each note, every note starts at the same point in the wobble. Predictable, punchy, good for riffs where the bass plays short notes.
Free-running (or synced to the song position), the wobble keeps its own clock and your notes land on different parts of the cycle. That’s how you get evolving patterns from one held note, and it stays locked to the beat even when the bassline syncopates. For long sustained wobbles I almost always use free-running. For choppy riddim-style stabs, retrigger.
Grit: FM and distortion
A filtered saw wobble is clean. Bass music usually isn’t. Two ways I add dirt:
- FM from oscillator B. Set B to a sine an octave or two below, route it to frequency-modulate A, and push the amount until the tone snarls. Modulate the FM amount with the same LFO as the filter so the grit breathes with the wub.
- Distortion in the FX chain, after the filter. Then EQ inside the chain to tame the harsh 3–5 kHz that distortion always adds.
When I made our Skrillex-inspired pack, nearly every patch used the same LFO on two or three destinations at once: cutoff, FM amount, and wavetable position. One LFO, three targets. That’s what makes a wobble feel like one living thing instead of a filter on a timer.
Protect the sub
The classic beginner mistake: the LFO wobbles the entire patch, sub included, and the low end pumps in and out. The track loses its floor every time the filter closes.
Fix it with a split. Keep a plain sine sub an octave below, either as a separate oscillator that skips the filter or as its own track. The sub holds steady, the wobble happens in the mids above roughly 100 Hz. Every professional bass house record works this way, which is why the drops feel huge and stable at the same time.
Want to see it wired up instead of reading about it? Grab the free Serum 2 bass house presets and open any bass patch. Look at what the LFO touches and, just as important, what it deliberately doesn’t.
Making it fit a track
A wobble that sounds huge solo usually eats the whole mix. Three habits:
- Sidechain the wobble layer to the kick, even lightly. The lurch tightens up.
- Cut a few dB around 300–500 Hz if the wub sounds boxy against the drums.
- Write the wobble rhythm against the drums, not on top of them. If the kick and the wub always land together, the groove flattens.
The same LFO-on-cutoff idea runs slap house and bass house too, just faster, tighter and with more sidechain. Same trick, different suit. If you want the whole family, the bass house and slap house folders sit right next to the dubstep ones in my Serum 2 preset catalog.
If you’re past the free packs and want a full library of finished basses across genres, the Serum 2 preset bundles are the cheapest way per preset to get there. No countdown timer, just the better deal.
For heavier territory, the dubstep growls guide builds on everything here, and the modulation guide covers what else an LFO can grab beyond cutoff.
FAQ
What LFO rate for a wobble bass?
Tempo-synced 1/4 for slow dubstep, 1/8 for the classic wub, 1/16 for fast talk. Automating between them across a phrase is the standard move.
Should the LFO retrigger on every note?
Retrigger for short choppy stabs, free-running for held notes so the pattern evolves and stays locked to the grid.
Why does my low end disappear when it wobbles?
The LFO is filtering your sub along with the mids. Split them: steady sine sub below 100 Hz, wobble only above it.
How do I make a wobble sound aggressive, not clean?
FM from a sine oscillator plus distortion after the filter, with the FM amount riding the same LFO as the cutoff.
An LFO, a filter, a drawn shape and a protected sub. Fifteen years on, that recipe still slaps, which is more than you can say for most production trends.
I run Monosounds.studio and make the packs myself. Ten-plus years of producing, 97+ releases, 16,000+ downloads. Every Serum 2 preset we ship passes a CPU check on a mid-range laptop and gets used in a real track before release. If it does not survive a mix, it does not go in the pack.
More about Maxim & the studio →
