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Free • Full Version VST3 • AU • Standalone v1.0.0

AuxHarmonizer

Polyphonic Vocal Harmonizer & Side-Chain Processor

AuxHarmonizer is a studio-grade 4-voice polyphonic vocal harmonizer and side-chain processor. Transform monophonic lead vocals into rich choral arrangements, modern vocal stacks, and robotic vocoder chords with intelligent scale detection or real-time MIDI keyboard control.

Pay What You Want 100% Free • Optional $0+ tip to support independent audio DSP
Harmony Engine: 4 Polyphonic Voices Routing: Direct Insert • Side-Chain Bus Control: MIDI Chords • Diatonic Scale Engine Acoustics: Sibilance Guard • Tube Drive
Creative Workflows

Where AuxHarmonizer Excels

Engineered for instant vocal depth, lush vocal beds, and expressive keyboard-driven harmonies.

Multi-Part Choral Arrangements

Generate lush 4-part choir backings snapped diatonically to your key. Dial in 3rd Above, 3rd Below, 5th, and octave doubling with independent formant shaping for realistic human ensembles.

Live MIDI Keyboard Harmony

Route your lead vocal into AuxHarmonizer via side-chain and play chords directly on your MIDI controller. Real-time pitch tracking re-pitches your voice instantly with full pitch-bend responsiveness.

Modern R&B Stacks & Prismizer Chords

Craft tight, wide modern vocal stacks with micro-pitch humanize, Haas stereo spreading, and subtle triode warmth to achieve stadium-sized vocal hooks without recording dozens of takes.

Architectural Innovations

Precision Polyphonic Vocal Processing

Every algorithm inside AuxHarmonizer is purpose-built to preserve vocal clarity, timing, and emotional expression.

Dual Track & Side-Chain Routing

Insert AuxHarmonizer directly on your vocal channel for immediate harmony, or place it on a dedicated bus and feed the dry vocal via your DAW's side-chain input to drive harmonies from any instrument track.

Routing: Direct Insert • Side-Chain Bus

4 Independent Voice Consoles

Each of the four harmony voices features dedicated mute and solo buttons, ±24 semitone transposition, ±50 cents micro-detuning, ±12 st formant character morphing, stereo pan, and gain control.

Consoles: 4 Distinct Stereo Channels

Linkwitz-Riley Sibilance Guard

A built-in 4th-order Linkwitz-Riley crossover at 5.2 kHz isolates consonants and vocal sibilants ("s", "t", "ch") from pitch shifting. Preserves crisp, uncolored high frequencies without phase smearing.

Crossover: 5.2 kHz 24 dB/oct Linkwitz-Riley

Intelligent Diatonic Scale Harmony

Choose your Root Key (C through B) and musical scale (Major, Minor, Pentatonic, Dorian, Mixolydian, Lydian, Chromatic) with voicing presets for instant triads, 7th chords, octaves, and gospel harmonies.

Scales: 7 Diatonic Modes + Voicing Presets

Live Spectral Pitch & Voice Telemetry

Integrated real-time spectral analyzer displays incoming vocal energy, an active fundamental F0 pitch tracking line, dynamic floating voice badges (V1–V4), and real-time side-chain signal presence.

Telemetry: Live Pitch & Voice Badges

Humanize, Triode Tube & Haas Width

Subtle analog micro-pitch drift and voice phase decorrelation prevent artificial comb filtering. Combine with modeled 12AX7 triode tube saturation and psychoacoustic Haas width for lush, immersive depth.

Warmth: Triode Tube • Haas Widener
Deep Dive

Parameter Specifications

Comprehensive parameter specifications for DAW automation and preset engineering.

Parameter Identifier Range Default Functionality
Mode harmonyMode MIDI Driven, Chord / Auto Chord / Auto Toggles between incoming MIDI chord trigger and automatic diatonic harmony generation.
Side-Chain Source sidechainSource Direct (Main Input), Side-Chain Bus Direct Selects whether audio is processed from the track insert or DAW side-chain auxiliary bus.
Root Key & Scale rootKey / scale 12 Notes • 7 Scales C Major Sets harmonic framework for diatonic interval computation in Chord / Auto mode.
Voicing Preset voicing Octaves, 3rd Above, 3rd Below, Triad, 7th, 4-Part Choir Triad Instant chord voicing intervals applied across voices 1 through 4.
Voice 1–4 Shift v1_shiftv4_shift −24 to +24 semitones 0, +4, +7, +12 st Individual semitone transposition interval for each harmony voice.
Voice 1–4 Detune v1_detunev4_detune −50 to +50 cents 0 cents Micro-pitch detuning for chorusing, thickness, and realistic vocal spread.
Voice 1–4 Formant v1_formantv4_formant −12 to +12 semitones 0 st Independent vocal tract resonance adjustment per voice to alter gender and timbre.
Voice 1–4 Pan & Gain v1_pan / v1_gain Pan: L100 to R100 • Gain: −inf to +6 dB Center / 0 dB Independent spatial placement and output volume for each individual voice console.
Sibilance Guard sibilanceGuard 0.0% to 100.0% 80.0% Blends dry unshifted high frequencies above 5.2 kHz to preserve natural vocal consonants.
Humanize Drift humanize 0.0% to 100.0% 25.0% Applies natural micro-pitch variations and phase decorrelation to prevent comb filtering.
Tube Drive tubeDrive 0.0% to 100.0% 10.0% Drives modeled vacuum tube triode circuit for warm second-order harmonic enrichment.
Stereo Width width 0% to 200% 120% Expands harmony voice field using Haas delay and mid/side psychoacoustic widening.
Master Dry / Wet dryWet 0.0% to 100.0% 50.0% Mix ratio between the untreated lead vocal and polyphonic harmony voices.

System Requirements & DAW Compatibility

AuxHarmonizer is tested and fully validated across major production platforms.

macOS

  • macOS 11.0 Big Sur or later
  • Native Apple Silicon (M1, M2, M3, M4) & Intel 64-bit
  • AU (Audio Unit), VST3, Standalone App

Windows

  • Windows 10 or Windows 11 (64-bit)
  • Intel Core i5 or AMD Ryzen equivalent
  • VST3, Standalone App

Verified DAWs

Ableton Live11 • 12
Logic Pro10.7+
FL Studio20 • 21
Pro Tools2023+
Studio Onev5 • v6
Reaper6 • 7
Cubase12 • 13
Bitwig Studio4 • 5

Build Rich Harmonies with AuxHarmonizer

Download the official release archive today. 100% free digital distribution for music producers, mix engineers, and vocalists worldwide.

Download Free / Pay What You Want