Serum for macOS

Description

If you've used LFOTool and wished you could shape those filter sweeps directly inside a proper synth, Serum 2 is where that idea landed. It borrows filter types from LFOTool and adds new ones, all inside a wavetable engine.

Getting the wavetables right

You can import, edit and transform wavetables in real time. The Unison WT Pos feature lets you assign a different waveform to all unison voices at once.

Working with filters

Dual filter types are built in, so you can switch between them or control both. Unison Warp sets unison voices differently for more movement.

Installing on a Mac

What one sound designer actually does with it

A game audio designer I know spends half her week building creature voices and sci-fi atmospheres. She doesn't reach for Serum 2 because it has 16-voice stacks — she reaches for it because she can drag a field recording of a rusty gate into the wavetable editor and turn it into something unrecognisable in under a minute.

Her workflow is simple: import the sample, scrub through the wavetable positions while a MIDI note holds, and listen for the three or four spots where the waveform gets interesting. She marks those, deletes the rest, and suddenly a squeaky hinge becomes a glassy pad that shifts between harmonics as she rides the mod wheel. No external editor, no offline processing. Just import, trim, play.

She also leans on the sample-rate reduction filter process for lo-fi drones. Dropping the bit depth on a reverb tail inside the filter section — rather than using a separate bitcrusher plugin — keeps everything inside one patch, which matters when a game studio asks for revisions six months later and she needs to remember what she did.

What changed after 2.0

The move from Serum 1 to Serum 2 wasn't a facelift. It was a rewrite of the modulation system and a big expansion of the filter section. The dual filter types now let you crossfade or hard-switch between two entirely different filter models — say, a comb filter that tracks pitch and a flanger that doesn't — which means one patch can morph from a resonant pluck to a swirling wash without touching an external effect.

Stack mode arrived quietly but changed how people build chord patches. Instead of loading three instances and linking their MIDI, you now set an oscillator to stack notes in octaves or fifths. Press one key, hear a chord. It's not polyphonic multitimbral — it's unison repurposed for harmonic layering, and it works best on monosynths where you want thickness without the phase smear of detune.

The flanger, phaser and comb filter additions all track the played note. That sounds minor on paper. In practice, a comb filter that follows your bassline means the resonant peaks stay locked to the key, so the effect doesn't drift out of tune as you play up and down the keyboard. It's the kind of detail that stops you from reaching for a separate tuning plugin.

Drag-and-drop modulation talks to LFOTool

Serum 2 runs as an AU or VST3 plugin, so it slots into Logic, Ableton Live, Bitwig, or whatever DAW you're using. It also talks to LFOTool over the same modulation philosophy — both use drag-and-drop modulation assignments, so if you've built muscle memory in one, the other feels familiar.

On macOS, the synth respects the system's audio routing. If you're using an aggregate device or a multi-output interface, Serum 2 shows up like any other instrument track. No special bridging, no wrapper. On Apple Silicon Macs it loads natively, which matters when you're running 40 tracks and the CPU meter is already twitching.

For sound designers who use a sample manager like Audio Finder or even just Finder tags, the wavetable import dialogue reads standard .wav files. You can drag from Finder straight onto the wavetable display. That cuts out the step of opening a separate editor just to trim silence off a sample before it reaches the synth.

Building a bass patch from a blank init

Here's what a typical hour looks like when someone sits down to build a bass patch from scratch.

First, initialise the patch. Serum 2 starts with a sawtooth wavetable by default. Hit the menu, choose 'Clear' to get a blank slate, then drag in a short .wav — something with a sharp transient, like a metal hit. The wavetable editor shows the waveform immediately.

Second, set the unison to 4 voices. Use Unison WT Pos to spread those four voices across different waveforms in the table, so each voice plays a slightly different slice of the sample. The sound thickens but stays clear because the waveforms aren't detuned copies — they're genuinely different.

Third, enable the dual filter. Route oscillator A into filter 1 — a low-pass ladder — and filter 2 — a comb that tracks pitch. Set the comb's feedback low, around 20%, so it adds a metallic ring without screaming. Assign the mod wheel to crossfade between the two filters. At wheel-down you get a warm sub; at wheel-up the comb takes over and the patch turns cold and hollow.

Fourth, add a stack. Set oscillator A to stack a fifth above the root note. Now one key press gives you a power chord. Drop the stack volume to around 40% so it reinforces the fundamental without becoming a lead sound.

Fifth, assign an LFO to the wavetable position. Use a slow triangle wave so the waveform morphs over two bars. The metal hit gradually warps into a smoother shape as the loop plays, and because the unison voices are locked to different positions, the whole thing breathes.

Sixth, save the patch. The DAW recalls everything next session. No notes to write down, no external routing to remember.

That's the kind of session where Serum 2 stops being a plugin and starts being a sound design tool you reach for because you know it'll get you there in six steps, not sixteen.

The synth runs on ARM and x86 64-bit Macs. Xfer provides getting-started instructions that walk you through the standard procedure.

What’s new

Adds an Ignore VST3 Note IDs setting for hosts that misbehave with note identifiers. Adds support for automatable parameter shortcuts in Pro Tools.

Fixes data loss when opening projects and sessions created in newer versions of Serum 2. Fixes pop-up tooltip display in Digital Performer. Fixes intermittent crashes in Digital Performer. Fixes loading of ACIDized WAV files with empty strc chunks. Fixes Clip Player macro automation updates in Bitwig Studio. Fixes MPE value retention after voice stealing. Fixes note preview in the Piano Roll so it now respects the velocity of the auditioned note. Fixes a potential crash when junk data is passed to the Serum processor. Fixes a broken settings interface introduced in version 2.0.22. Fixes preset selection via the Previous/Next buttons so loading a session no longer jumps incorrectly to ARP — Aardvark. Fixes a Pro Tools hang on quit in Windows. Fixes incorrect interface scaling in JUCE-based hosts when Windows Display Scaling isn't set to 100%.

Requirements

• macOS 10.13 or later
• Apple Silicon or Intel 64-bit