Serum Unison Modes Explained – Which One to Use

What Are Serum Unison Modes?

Unison is one of the most used features in Serum, but most producers just crank up the voice count and detune without understanding what the different unison modes actually do. Each mode distributes the unison voices differently across the stereo field and pitch range, and the mode you choose has a massive impact on the width, thickness, and character of your sound.

Serum offers several unison modes. Each one stacks and distributes voices using a different algorithm. Understanding these differences lets you make informed choices about which mode to use for different types of sounds, rather than always defaulting to the same setting.

Unison Mode Breakdown

Off

No unison. A single voice plays for each oscillator. This gives you the cleanest, most focused sound with zero width and zero detuning artifacts. Use this for clean sub bass, precise leads, and any situation where you need a tight, mono sound with no spread.

Super

This is the default mode and probably the most commonly used. It distributes voices evenly across the stereo field with equal detuning in both directions from the centre pitch. As you add more voices and increase detune, the sound gets wider and thicker. This is the go-to for big, wide supersaws and thick bass stacks.

Super mode works well with higher voice counts (7-16) for massive pads and leads. For bass, keep the voice count lower (2-4) to maintain tightness and avoid phasing issues in the low end.

Superx2

Similar to Super but with a doubled spread algorithm. Each voice pair is spread wider than in standard Super mode, creating an even bigger stereo image. The trade-off is that the centre of the sound can feel slightly thinner because the voices are pushed further apart.

This mode works brilliantly for huge pad sounds and cinematic textures where you want maximum width. For bass, it can be too wide and cause mono compatibility issues, so use it cautiously and check in mono.

Linear

Voices are distributed linearly across the pitch range. The detuning is evenly spaced, creating a more orderly, less chaotic spread than Super mode. Linear mode sounds slightly smoother and more controlled, making it good for clean, professional-sounding detuned stacks.

It is particularly useful for sounds that need to be wide but clean, like EDM leads, trance supersaw stacks, and bright pads. For bass, it gives a more predictable, less muddy detuning than Super mode.

Exp

Exponential distribution clusters more voices near the centre pitch and spreads fewer voices to the extremes. This creates a thick centre with subtle spread at the edges. The result sounds denser and more focused than Linear or Super because the bulk of the voices are close together in pitch.

This is excellent for bass sounds because it gives you thickness without excessive width. The closely clustered centre voices create density and weight, while the few outer voices add just a hint of spread. Many professional bass presets use Exp mode because it provides the fatness of unison without the mono compatibility problems.

Random

Voices are randomly distributed each time a note is triggered. This means no two notes sound exactly the same, which creates a more organic, analogue-like quality. The randomness can be subtle or dramatic depending on the detune amount.

Random mode is great for pads and atmospheric sounds where you want each note to feel slightly different. It works less well for bass where you typically want consistent, predictable results on every note.

Voice Count and Detune Amount

The number of unison voices and the detune amount work together with the mode to determine the final sound. More voices means a thicker sound but more CPU usage. Higher detune means wider spread but also more pitch instability.

Bass Recommendations

For sub bass: 1 voice (no unison). Keep it clean and mono. For mid bass: 2-4 voices with low detune (0.10-0.20) in Super or Exp mode. This adds thickness without creating phasing problems. For lead bass or aggressive sounds: 4-7 voices with moderate detune (0.20-0.35) in Super mode. This gives you width and aggression while remaining manageable.

Pad and Lead Recommendations

For wide pads: 7-16 voices with moderate to high detune (0.25-0.40) in Super or Superx2 mode. For clean leads: 4-7 voices with low detune (0.10-0.20) in Linear mode. For analogue-style sounds: 2-4 voices with low detune in Random mode for that vintage, imperfect character.

Blend and Stack Controls

Serum also includes Blend and Stack controls in the unison section. Blend adjusts the volume relationship between the centre voice and the outer voices. At 0%, only the centre voice plays. At 100%, all voices are equal. Settings around 50-70% give a good balance where the centre provides a solid anchor and the outer voices add width.

Stack adds additional octave layers on top of the unison voices. Stack x2 adds an octave above, Stack x3 adds octaves above and below. This is useful for creating instant, full-range sounds without needing multiple oscillators. But be aware that stacking dramatically increases CPU usage.

Choose the Right Mode for Your Sound

The key takeaway is that unison mode choice should be deliberate, not random. Think about what you need from the sound. Width? Thickness? Focus? Consistency? Organic variation? Then choose the mode that delivers that quality. Your bass will sound more professional and more intentional as a result.

Hear these modes in action with professionally designed presets. Download the Free Serum Taster Pack and study the unison settings used in each preset. Then explore the Preset Drive shop for more sounds that demonstrate expert use of Serum unison system.