Serum Tutorial: Wavetables, Modulation and Sound Design

Serum: Flexible Sound Design and an Intuitive Interface

Serum, developed by Xfer Records, is a software synthesizer used in many production environments.
Its intuitive interface and strong sound quality have kept it popular in electronic music and sound design years after release.
Here we will explore its features and operation in detail.

Serum Video: Overview and Customizing Presets

Questions and Answers from YouTube

Does it come with presets?

Yes, many presets are included with the purchase.

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Choosing Presets

Serum includes many appealing presets, including ones created by artists.
Starting from a preset is a useful way to find a sound you like.

Choose a preset from the small black window at the top of the screen.
Use the adjacent < and > buttons to audition presets one after another.

Serum’s Basic Architecture

Once you have chosen a starting preset, understand the basic architecture to customize it.

Serum has two main oscillators (yellow), a sub oscillator (blue) and a noise oscillator (green).
Use the blue button beside each name to turn it on or off, and use LEVEL to adjust the balance.

The DIRECT OUT button beside SUB lets you choose whether the sub oscillator bypasses the effects.
Turn DIRECT OUT on when you want the sub bass to bypass effects.

Click the “Default” area for OSC A or B to choose its waveform, or wavetable.
The < and > buttons step through the choices.
There are many options, and you can preview each one as you select it.

Envelopes and LFOs

To add movement, use the envelopes and LFOs at the bottom of the screen.
The three envelopes are on the left and the four LFOs on the right.
In this preset, the number 7 beside LFO1 means the LFO is assigned to seven parameters.

Right-click that number to see the assigned destinations.
You can perform these actions:

• Parameter name: Toggle the assignment on or off.
• Bypass (Activate) All Destinations: Temporarily disable or restore the LFO assignments.
• Remove All Destinations: Delete the LFO assignments.

LFO Basics

Click the folder icon above the LFO controls to choose an LFO shape preset.

Next, adjust RATE.
Turning RATE clockwise makes the cycle shorter and the movement faster.
Turn on BPM to synchronize the cycle to the song tempo; RATE then displays values such as 1/2 or 4.
Use this when you want the motion to follow the beat.

Envelope Basics

ENV1 is assigned to the main amplitude envelope.
Turn ENV1 ATTACK or move the upper-left point in the display to change the sound’s attack.

If the release portion is outside the display,
drag vertically on the magnifying-glass control on the right to show the entire envelope.

Viewing Envelope and LFO Destinations

You can also see destinations visually.
Click an ENV or LFO tab with a number, and the assigned knobs light up blue.

Drag the marker at the top left of a knob up or down to set the modulation range.

Filter Overview

In Serum’s filter section, use the buttons on the left to choose which oscillators pass through the filter.
In this example, the B/P/N 12 filter is applied to OSC A and NOISE.
Envelopes and LFOs can easily be assigned to parameters, giving you extensive sound-design flexibility.

Saving and Loading Presets

Save your customized sounds as you create them.

Click the disk icon beside the preset name, enter a name, and click Save.

To load one later, look in the User folder.

Oscillator Basics

Next we will explore Serum’s wavetable oscillators.
The oscillators are central to a sound’s character, and Serum includes a wide range of waveform presets.
Combine waveforms or use your own audio files for flexible sound design.

Serum Video: Oscillator Controls

Choosing a Waveform

Choose a waveform for OSC A and OSC B.
Click “Default” or use the left and right arrows to change it.
Audition the many choices and select the sound you prefer.

Changing Pitch

The oscillator lets you change its basic pitch.
For example, leave OSC A unchanged and raise OSC B by one octave for a fuller sound.

• OCT (red): Change pitch in octaves.
• SEM (blue): Change pitch in semitones.
• FIN (yellow): Fine-tune in cents.
• CRS (green): Adjust pitch over a range of six octaves in either direction, in cent increments.

Applying Unison

UNISON lets you layer the selected number of voices.
This thickens the sound and spreads it in stereo.

DETUNE changes the pitch of the unison voices to add chorus-like thickness.
Turn the knob clockwise for a stronger effect.

Under GLOBAL, RANGE lets you change the DETUNE pitch range.
It is adjustable in semitones; a larger value gives a greater pitch change.

BLEND adjusts the level balance between the center and side unison voices.
Listen and adjust for the width and image you want.

Changing Waveform Playback Position

You can set where playback begins within an oscillator waveform.

• PHASE: Set the start position.
• RAND: Randomize the start position around that setting. Higher values widen the range, varying the sound on each MIDI note.

Applying FM and Sync

Serum also supports FM and Sync, common synthesis techniques.
Click OFF in the Warp section to open its menu.
FM and Sync are among the choices.

Sync resets one oscillator’s waveform according to another oscillator’s cycle, creating harmonics.
Turn the knob clockwise to make the resets more frequent and change the sound more dramatically.

FM uses the selected oscillator waveform to modify the sound.
In this example, From B is selected, so OSC B must be on.
Even with OSC B LEVEL at zero, its signal is sent to OSC A as a modulation source.
Adjust the FM amount with OSC A’s warp knob.

Using Wavetable Position

Each oscillator can contain a table of multiple waveforms.

Use WT POS to select a waveform from the table.
Turning WT POS selects the waveform to play, providing variations in the sound.

Click the waveform display to visualize the table.
The yellow line shows the waveform selected by WT POS.
Some selected wavetables contain only one waveform.
In that case, turning WT POS does not change the sound.

Creating a Wavetable in the Editor

You can create and load your own wavetable.

Click the pencil icon to open the wavetable editor.
The waveforms in the blue-outlined area are the frames selected by WT POS.

Let’s add a frame.
Press + to duplicate the selected waveform in the next position.
The − and + controls above the frame area also remove or duplicate the selected frame.

Drag with the tools on the left to design the waveform.

For finer edits, use the zoom control at the lower right.

Select a waveform, click COPY, choose a destination and click PASTE to duplicate the waveform at that position.

Creating a Wavetable with FFT

Another way to create a wavetable is FFT.

• FFT Area (Yellow)

The frequency spectrum displays the amplitude of each frequency component.
The fundamental is at the far left, followed by the second and third harmonics; the vertical axis shows amplitude.
Adjust the harmonics to change brightness and thickness.

• Phase Area (Blue)

This visualizes the phase of each frequency component and the timing relationship between harmonics.
Changing phase alters the waveform shape and can change its character and the prominence of harmonics.

Morphing a Wavetable

After setting up the frames, turn WT POS to move between them.

Serum provides morphing to make the transitions smooth.
Click the pencil icon and select an option from the Morph menu.
Here we use the manufacturer-recommended Morph – Crossfade, but try the other options to find an effect you like.

The frames transition smoothly as WT POS moves.

Importing Your Own Audio

Serum can analyze your own audio files and use them as oscillator waveforms.

Drag the desired audio file directly onto the oscillator.

Choose the material type for appropriate analysis.

• Normal (dynamic pitch zero-snap): For material with simple changes in level and pitch.
• Normal (dynamic pitch follow): For material with larger changes in level and pitch.
• Constant frame size: Recommended for one-shots.
• FFT: For sounds with indistinct pitch, such as drums and effects.

The file is analyzed and loaded into the oscillator.
Adjust WT POS until you find a sound you like.

Understanding the Sections That Add Movement

Next we will cover modulation, with a focus on LFOs.
An important part of synthesis is deciding how modulation will make a sound move.
Learn this section and use it to create a variety of sounds.

Serum Video: Modulation Controls

LFO Section

Serum provides four LFOs.
Drag an LFO onto a parameter to assign it.

Drag the red-outlined marker vertically to adjust the LFO range.
The blue line indicates that range.

Many LFO shape presets are available.
Browse them using the folder icon.

Use RATE to change the speed of the repeating LFO cycle.

Turn on BPM to synchronize the cycle to the song tempo.
The RATE value “bar” refers to a measure: one complete LFO cycle per bar.

Other parameters allow finer control over LFO movement.

• RISE (blue): Fade in the LFO effect over time.
• DELAY (yellow): Delay the start of the LFO.
• SMOOTH (green): Smooth the LFO movement.

These controls can make a sound change gradually.

You can also draw your own LFO shape.
Shift-click to add a step snapped to the grid, or double-click a line to add a point.
Double-click an existing point to remove it.
Drag the blue point between nodes to adjust the curve.

Set GRID to quarter, eighth or sixteenth notes to display grid lines as a rhythmic guide.

• Mac: Option
• Windows: Alt

Hold the key while dragging to work in the selected grid increments.

Here you can select the LFO trigger MODE:

• TRIG: Restarts the LFO cycle on each MIDI note.
• ENV: Plays the LFO cycle once.
• OFF: Repeats the cycle independently of MIDI note-on.

You can save your custom LFO.
Click the folder icon, choose Save Shape, enter a name and click Save.

Saved shapes are available under User.

Matrix Settings

The Matrix lets you fine-tune the ranges of LFO and envelope modulation.

• SOURCE (red): Select the LFO or envelope.
• DESTINATION (blue): View or select the parameter being modulated.
• AMOUNT (green): Set how much the source changes the parameter.
• TYPE (purple): Change the source movement to bipolar.

Assign several modulations to a MACRO and control them together.
Choose the desired MACRO under AUX SOURCE.

You can also register a MACRO by dragging it directly onto a parameter.

Sound-Design Examples Using Serum

Now that we have covered the controls, let’s look at practical sound-design tips using those features.
Even complex-sounding patches can be easier to create than they seem with the right tools.
Let’s take them one at a time.

Serum Video: Simple Sound-Design Tips

Bouncy Bass

The bass in the sample track has a light, slightly hard, bouncy character.
Oscillators A and B use sine-type waves, though A has a slightly different shape.
The sine wave is not selected from the normal wavetable menu, so click the pencil icon at the upper right to edit.

Then choose Singles from the lower-right menu to select basic waveforms.

Here, select Phat Sub for OSC A and sin for OSC B.

Instead of sounding both oscillators, use OSC B to ring-modulate OSC A.
Set OSC B’s level to minimum, choose RM (FROM B) in OSC A’s WARP and adjust it to taste.

Leave a little release on the main envelope and apply compression in FX to finish.

Sidechain-Style Backing

Sidechain effects normally use a signal from another track to control an effect such as a compressor, but Serum can imitate the effect internally.

Set both oscillators to saw waves and raise OSC B by one octave.
Adjust UNISON, DETUNE and BLEND for a supersaw-style sound.

Use an LFO for the simulated sidechain effect.
Assign LFO1 to each oscillator’s LEVEL, turn BPM on and set RATE to 1/4.

Choose Sidechain from the folder and pick a curve you like.

The example adds HYPER DIMENSION, PHASER and REVERB.

Gently Moving Pad

Let’s make a clear pad with subtle LFO movement.

Set a slow attack on the main envelope for a pad-like sound.
Use a somewhat longer release too.

Set OSC A WARP to MIRROR and choose Analog → Basic Shapes.
Set OSC B WARP to BEND, centered, and choose Digital → ICanHasKick.
Apply unison to both and adjust DETUNE and BLEND.
Mix in a little sine wave from SUB.

Assign LFO1 to OSC A MIRROR.
Use a sine shape, BPM on, RATE set to BAR, and Matrix type ↔.

Assign the same LFO1 to OSC B WT POS.
Set Matrix type to → so it does not move left of the knob’s starting value.

Finish with a high-pass filter and spatial effects such as HYPER DIMENSION and DELAY.

A Sequence That Changes with Velocity

In Serum you can use velocity to modulate many parameters.
Drag VELO, to the right of the LFO section, onto a parameter.

In this example, assign VELO to WT POSITION and WARP on both oscillators.
The minimum and maximum velocities correspond to the blue indicator range for each parameter.
Assign it to a filter as well for a more pronounced change.

Program the phrase with varied velocities.

A Complex Moving Lead

First, set up portamento so the lead notes connect smoothly.

Overlap only the notes you want to connect.

Turn on MONO and LEGATO at the lower right, then raise PORTA to adjust the pitch transition speed.

For OSC A choose Multis → saw/sin reveal.

Set WARP to SYNC and assign LFO1, with Matrix type ↔.
Keep the range very small.

Set LFO RATE to 1/16 and RISE to BAR.
RISE fades in the LFO effect, so sustained notes gradually develop modulation later in the note.

For OSC B, start with a saw wave and UNISON at 2, shape the sound, then set GLOBAL UNISON RANGE to 24.

Set LFO2 to a square wave and assign it to DETUNE with a full bipolar range.
The key is to start DETUNE fully right and extend the modulation range left.
(This is the opposite of the setting shown above.)

Set LFO DELAY to 1/4 to start the LFO effect one quarter note later.

That concludes our tips for using Serum’s features in sound design.
Try them and use them as a starting point for your own patches.

Frequently Asked Questions

Q1. Can beginners use Serum?

Yes. Its clear interface and many presets make it approachable. Start with a preset and customize it to learn sound design.

Q2. Where do I choose presets?

Use the small black window at the top. The adjacent < and > buttons let you audition presets, including ones made by artists.

Q3. Can I save my own presets?

Yes. Click the disk icon beside the preset name, enter a name and save. Your presets are stored in the User folder.

Q4. How can I make sounds fuller?

Layer unison voices, combine OSC A and B at different pitches, or use detune for chorus-like thickness and width.

Q5. What does Serum’s envelope control?

ENV1 controls the main amplitude envelope. ATTACK sets how the sound starts and RELEASE controls its fade after note-off. Envelopes can also be assigned to other parameters.