The granular engine is the part of Serum 2 most people open once, get scared by, and never touch again. Which is a shame, because Serum 2 granular synthesis is the fastest way I know to turn a boring sample into a living, breathing texture.
I’ve built granular patches for our preset packs since the engine shipped in March 2025. Some started as a two-second vocal snippet. Some started as vinyl noise recorded off my own turntable.
In this tutorial I’ll cover the three controls that actually matter, give you three recipes you can copy today, and show you how to stop granular patches from eating your CPU alive.
How the Serum 2 Granular Engine Works
Every oscillator in Serum 2 can switch between five engines: Wavetable, Sample, Multisample, Granular, and Spectral. I covered all five in my guide to Serum 2 oscillator types, so here’s the short version.
Granular chops a sample into tiny slices called grains and plays them back as a stream. Each grain has its own pitch, position, and length. Serum 2 runs up to 256 grains at once per oscillator.
That’s the whole trick. A dense, overlapping stream of long grains sounds like a pad. A sparse stream of short grains sounds like a glitchy rhythm. Same sample, same engine, different settings.
Getting started takes ten seconds: drag any .wav onto an oscillator and switch the engine to Granular. No separate sampler, no third-party plugin.
Grain Size, Density, and Position Explained
There are more knobs on the granular page, but three of them do 90% of the work.
Grain size is how long each slice lasts. Long grains (150 ms and up) keep the character of the source – you can still hear that the vocal is a vocal. Short grains (under 50 ms) destroy the source and leave you with pure texture, or clicks if you go too far.
Density is how many grains fire over time. Low density means gaps and stutter. High density means grains overlap and smear into a continuous wall. For pads I push density up until I can’t hear individual grains anymore.
Position is where in the sample each grain is taken from. Leave it parked and you get a frozen drone. Modulate it slowly and the sound scans through the sample like a tape head. Every Serum 2 granular patch I’ve shipped leans on position modulation more than anything else.
Here are the starting points I actually use:
| Goal | Grain size | Density | Position |
|---|---|---|---|
| Smooth pad | 150-250 ms | High, fully overlapping | Slow LFO, 4-8 bar sync |
| Rhythmic chops | 40-60 ms | Low to medium | Stepped LFO, 1/16 sync |
| Lo-fi noise bed | 80-120 ms | Medium-high | Slow drift plus a little random |
| Glitch FX | 10-30 ms | Low | Fast random jumps |
Treat these as defaults, not rules. Every source sample reacts differently, and half the fun is finding out how.
Three Serum 2 Granular Recipes
These are real patches from my template. Copy the settings first, then swap in your own samples.
Recipe 1: Texture Pad From a Vocal
Take any vocal phrase, one to four seconds long. Dry works better than reverb-soaked – you’ll add space later.
Drag it onto OSC A and switch to Granular. Set grain size around 200 ms, then push density up until the gaps disappear. Turn keytracking on so the patch plays in tune across the keyboard.
Now the important part: assign a slow LFO to grain position. I sync it to 8 bars, triangle shape, full depth. The patch slowly scans through the vocal and never plays the same texture twice.
Finish with a low-pass filter around 8 kHz and one of the three new reverb types on its own FX bus. If the pad needs more body, add a quiet wavetable saw on OSC B – I wrote a full guide on building pads and atmospheres in Serum 2 if you want to take this further.
Recipe 2: Rhythmic Grains Synced to BPM
This one turns any sustained sample into a groove element. I use it constantly in tech house at 124 BPM – several patches in our tech house presets roundup are built exactly this way.
Start with grain size at 40-60 ms and density low enough that you hear individual grains. Then assign an LFO to grain position, set the LFO shape to steps – 8 or 16 of them – and sync it to 1/16.
Now every 16th note jumps to a new spot in the sample. Instant rhythmic chop. Run it through the built-in arpeggiator with per-step velocity for extra groove, and keep the amp envelope short and gated.
One more trick: drop the grain pitch by 12 semitones on every fourth step via the mod matrix. It reads as a bass answer living inside the same patch.
Recipe 3: Lo-Fi Texture From Vinyl Noise
Record four bars of vinyl crackle, or use any noise bed you have lying around. Drag it onto an oscillator, switch to Granular, set grain size around 100 ms and density medium-high.
Add a small amount of randomness to grain position so the crackle never loops audibly. Low-pass everything at 4 kHz. Tuck it under your keys or chords at around -18 dB and the whole track suddenly sounds warmer.
This is the exact trick behind half the textures in our Melancholic Lo-Fi pack. And if you want ready-made ambient beds, our free Serum 2 atmosphere presets use these same granular moves – open them and study the mod matrix.
That goes for everything in this article, actually. Our free pack of 250+ Serum 2 presets includes atmospheres and textures built with these exact recipes, and reverse-engineering a finished patch teaches faster than any tutorial.
Granular Eats CPU. Here’s How to Control It
Fair warning: Serum 2 granular patches are the heaviest thing in the synth. The math is brutal – grain count multiplies with density, unison, and polyphony. Hold an 8-note chord on a dense patch with unison 7 and your laptop fan takes off.
Here’s what I do on every granular patch, in order:
- Drop unison to 3 on the granular oscillator. Granular already sounds wide; unison 16 is wasted heat.
- Cap the density. If the texture sounds the same at half the density, use half the density.
- Limit polyphony. Pads rarely need more than 8 voices.
- Keep oversampling at 2x. Granular textures almost never benefit from more.
When the part is written, freeze the track. Or better: use Resample to Oscillator, which renders your granular patch – FX included – into a new wavetable. The resampled version costs a fraction of the CPU and you can still play it live.
If you see graphics glitches rather than audio dropouts, set UseOpenGL=0 in your Serum.cfg file. Xfer also publishes official CPU guidelines – start from the Serum 2 page on Xfer’s site if you’re running an older machine.
Serum 2 Granular FAQ
Is the granular engine as good as a dedicated granular synth?
For musical work – pads, textures, rhythmic chops – yes. Dedicated tools go deeper into experimental territory, but Serum 2 wins on workflow: your granular oscillator sits right next to a wavetable oscillator, the full mod matrix, and multiple FX buses. For most tracks, that’s the better trade.
What’s the difference between the granular and spectral engines?
Granular works in the time domain: it slices the sample into grains. Spectral works in the frequency domain: it resynthesizes the sample from its partials and lets you edit them individually. Granular is better for texture and rhythm; spectral is better for morphing and surgical redesign. I compared them side by side in my spectral oscillator guide.
Can I use my own samples for granular?
Yes. Drag any .wav straight onto an oscillator and pick the Granular engine. Vocals, field recordings, old song stems – anything a few seconds long works great. Longer samples work too, but position modulation gets harder to control.
Why does my granular patch crackle?
Usually CPU, not the patch. Check density and unison first, raise your audio buffer to 256 or 512 samples, and freeze the track once the part is done. If it still crackles at low CPU load, your grains are probably too short – grains under about 20 ms click by nature, so lengthen them or lower the density.
Start With a Sample You Love
Granular in Serum 2 isn’t an experimental toy. It’s a practical texture machine that lives inside the synth you already own – and since the upgrade from Serum 1 is free, there’s no reason not to learn it.
If you want a head start, grab our 250+ free Serum 2 presets – atmospheres, pads, keys, and more, all royalty-free. Tear the granular patches apart, steal the mod routings, and build your own from there.
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.
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