Mixer

Module ID: util.mixer Category: Utilities Header Color: Yellow

Mixer Module The Mixer module

Description

The Mixer combines multiple audio or control signals into a single output. This 2-channel mixer allows you to blend signals with independent level control for each channel, plus a master output level.

Mixers are essential for:

  • Combining multiple oscillators
  • Blending modulation sources
  • Creating submixes before effects
  • Layering sounds

Inputs

PortSignal TypeDescription
Ch 1Audio/Control (Blue/Orange)First input channel
Ch 2Audio/Control (Blue/Orange)Second input channel

Outputs

PortSignal TypeDescription
MixAudio/Control (Blue/Orange)Combined output of both channels

Parameters

KnobRangeDefaultDescription
Ch 1 Level0.0 - 1.01.0Level of channel 1 in the mix
Ch 2 Level0.0 - 1.01.0Level of channel 2 in the mix
Master0.0 - 1.01.0Overall output level

How It Works

The mixer sums the inputs after applying their respective levels:

Mix = (Ch1 × Ch1Level + Ch2 × Ch2Level) × Master

Important: Summing two full-scale signals can exceed the -1 to +1 range. Use the channel levels to prevent clipping, or rely on the output module's limiter.

Usage Tips

Combining Oscillators

Create a richer sound by mixing multiple oscillators:

[Oscillator 1 (Saw)] ──> [Mixer Ch 1]
[Oscillator 2 (Square)] ──> [Mixer Ch 2]
[Mixer] ──> [Filter] ──> [VCA] ──> [Output]
  • Detune oscillators slightly for thickness
  • Use different waveforms for complexity
  • Adjust levels to taste

Detuned Unison

Classic "supersaw" technique:

[Osc 1 (Detune: 0)] ──> [Mixer Ch 1]
[Osc 2 (Detune: +7 cents)] ──> [Mixer Ch 2]

The slight pitch difference creates a chorusing effect.

Octave Layering

Add harmonic richness:

[Osc 1 (C3)] ──> [Mixer Ch 1]
[Osc 2 (C4, octave up)] ──> [Mixer Ch 2] (Level: 0.5)

Lower the higher octave to keep the fundamental prominent.

Blending Modulation

Combine modulation sources:

[LFO (slow)] ──> [Mixer Ch 1]
[Envelope] ──> [Mixer Ch 2]
[Mixer] ──> [Filter Cutoff CV]

The filter responds to both the cyclic LFO and the triggered envelope.

Wet/Dry Effect Blend

Mix processed and original signals:

[Audio] ──> [Effect Input]
        ──> [Mixer Ch 1] (Dry)
[Effect Output] ──> [Mixer Ch 2] (Wet)
[Mixer] ──> [Output]

Adjust channel levels to control effect intensity.

Audio + Sub-Oscillator

Add weight with a sub-bass:

[Main Osc (Saw)] ──> [Mixer Ch 1]
[Sub Osc (Sine, -1 octave)] ──> [Mixer Ch 2] (Level: 0.6)

Chaining Mixers

Need more than 2 channels? Chain mixers:

[Osc 1] ──> [Mixer A Ch 1]
[Osc 2] ──> [Mixer A Ch 2]
[Mixer A] ──> [Mixer B Ch 1]
[Osc 3] ──> [Mixer B Ch 2]
[Mixer B] ──> [Output]

Or use multiple mixers into a final mixer.

Level Staging

Manage levels to avoid clipping:

  1. Set individual channel levels to ~0.7 each
  2. Adjust Master to compensate
  3. Watch output levels (use Oscilloscope if needed)

Crossfading

Create a crossfade with complementary levels:

Ch 1 Level: 1.0 → 0.0
Ch 2 Level: 0.0 → 1.0

As one fades out, the other fades in. Automate with an LFO or envelope.

Connection Examples

Dual Oscillator Synth

[Keyboard V/Oct] ──> [Osc 1 V/Oct]
                 ──> [Osc 2 V/Oct]
[Osc 1] ──> [Mixer Ch 1]
[Osc 2] ──> [Mixer Ch 2]
[Mixer] ──> [Filter] ──> [VCA] ──> [Output]

Parallel Modulation

[LFO] ──> [Mixer Ch 1]
[Random/S&H] ──> [Mixer Ch 2]
[Mixer] ──> [Parameter CV]

Submix for Effects

[Lead Synth] ──> [Mixer Ch 1]
[Pad Synth] ──> [Mixer Ch 2]
[Mixer] ──> [Reverb] ──> [Output]

Gain Staging Tips

ScenarioCh 1Ch 2Master
Equal blend0.70.71.0
Ch 1 dominant0.90.41.0
Subtle layer1.00.21.0
Quiet mix1.01.00.5

Audio vs Control Signals

The mixer works with both audio and control signals:

Audio Mixing:

  • Combines waveforms
  • Creates complex timbres
  • Watch for clipping

Control Mixing:

  • Combines modulation sources
  • Creates complex modulation shapes
  • No clipping concerns (but consider destination range)