Kalibrus Noise & Spectral Reference

Kalibrus is a three-in-one studio device for the Reason Rack: a precision mix and acoustic reference, an expressive note-tracked noise synthesizer, and a random voltage generator.

While engineered with 32-bit floating-point precision and lab-calibrated algorithms, Kalibrus is built for practical, everyday music production:

• Playable Synth Voice: Tracks keyboard pitch and velocity. Push your Mod Wheel to narrow the passband for tuned wind leads, breath chiffs, or acoustic grit layered over synths.
• Tape-Bed “Glue”: Injects a warm analog noise bed under your mix. Built-in audio passthrough means no extra routing, and auto-engage silences the noise automatically when playback stops.
• Beef Up Drums & Claps: Layer keyed bursts of filtered noise underneath snares or claps. Dial the Stereo Width from 0% mono up to 200% wide for instant top-end sizzle.
• Easy Pink Noise Mix Balancing: Calibrated -18 dBFS True RMS pink noise lets you balance your mix track-by-track without second-guessing your ears.
• Random Movement & Generative CV (S&H): Sends a stepped random voltage on every note to modulate cutoff, pan, or pitch on any synth in your rack.

Get Kalibrus today (or try the 30-day trial) to audition the 35 factory patches in your own mixes.

Three Functional Engines in One Device

Kalibrus combines three dedicated tools in a single 2U rack device (with a full-featured compact folded strip):

1. Expressive Synthesizer Voice

Most noise generators just hiss; Kalibrus is built to be played like an instrument:

• Pitch Tracking: Incoming MIDI notes and rear Note CV shift the center frequency of the internal bandpass filter to track melodies and basslines across a 10-octave range.
• Mod Wheel Bandwidth Narrowing: Pushing your Mod Wheel dynamically narrows the filter passband from wide-open noise down to a focused 2-semitone resonant bite. Built-in automatic gain compensation prevents volume dropouts as the bandwidth tightens.
• Velocity-Sensitive Voice Gating: When disengaged on the front panel, Kalibrus stays dead silent until triggered by MIDI keys or rear Gate pulses, opening with a smooth, click-free attack. Smart release following keeps the voice gate open until external envelopes and audio tails decay naturally to silence.

2. Calibrated Acoustic Reference

Engineered to laboratory tolerances for critical mixing, room acoustics, and monitor calibration:

• Three Precision Spectra: Select between pure White (0 dB/oct, flat from 20 Hz to 20 kHz), Pink (-3 dB/oct, equal energy per octave via an optimized 6-pole + 1 FIR Paul Kellet filter within ±0.5 dB), and Brown (-6 dB/oct, DC-blocked leaky integrator with warm low-end weight).
• Calibrated Unity Level: Calibrated to -18.00 dBFS True RMS at the 12 o’clock center detent, providing an immediate, reliable standard for SPL alignment and pink-noise mix leveling.
• Cascaded 24 dB/octave Butterworth Filters: Independent 4th-order High-Pass and Low-Pass filters with Nyquist-linearized 2x polyphase oversampling and click-free, bit-exact DSP bypass at their extremes.

3. Random Voltage & CV Hub

Dedicated random and audio-rate CV sources for the rest of your rack:

• Gate-Triggered Sample & Hold CV Out: Generates a discrete, held random voltage on every note strike or gate trigger for stepped filter sweeps, random panning, or generative melodies.
• Continuous Noise CV Out: Post-filter fluctuating voltage whose speed and character are sculpted directly by the front-panel HPF and LPF cutoff knobs.
• Gate Relay Out: Velocity-aware gate output retransmits incoming notes to trigger external synths, envelopes, or downstream samplers in perfect sync.

Session Routing & Transport Automation

• AUTO Transport Sync: Flip the switch to AUTO to have noise engage only while DAW playback is running, instantly silencing to zero-CPU standby when playback stops.
• MAN (Manual Engage): Latches continuous noise generation for hands-free SPL monitor calibration and room acoustic sweeps. Or hold noise generation hands-free using your keyboard’s MIDI Sustain Pedal.
• Zero-Loss Audio Passthrough & Summing: Connect any mix bus or instrument track through the rear Inputs (Thru Raw) jacks. Your incoming audio always passes through at clean unity gain. Engaging Kalibrus sums calibrated noise directly into your track without needing a Spider Audio splitter or utility mixer.
• Constant-Power Mid/Side Matrix & True Stereo Balance: Adjust the stereo image from 0% mono to 200% wide with constant-power loudness normalization. The level-invariant True Stereo Balance control (0 dB center) maintains an exact -18.00 dBFS True RMS reference when isolating a single speaker for SPL calibration, with zero pan-law level boosts or clipping.

Rear-Panel CV Patchbay Matrix

• Dedicated CV Inputs: Pitch CV In (1V/oct), Gate CV In, Bandwidth (Mod Wheel) CV In, HPF CV In (bipolar ±10 octaves with rear trim pot), LPF CV In (bipolar ±10 octaves with rear trim pot), and Level CV In.
• Level CV — VCA / ENV Mode: Rear mode toggle selects unipolar envelope following from silence up to the front-panel Noise Level setting with positive trim, or smooth progressive sidechain ducking with negative trim.
• Level CV — TREM / LFO Mode: Rear mode toggle selects bipolar linear amplitude modulation for LFOs centered around nominal gain without runaway clipping.

Patches & Rack Workflow

• 35 Curated Factory Presets: 27 sound design and calibration patches organized into 5 practical categories (Reference & Calibration, Mixing & Diagnostics, Acoustic Room Probes, Textures & Modulation, and Performance & Layering), plus 8 quick starter patches for instant 1-click access.
• Compact Folded Mastering Strip: When rack real estate is at a premium, collapse Kalibrus into a compact folded strip. It keeps patch browsing, noise color, filter cutoffs, stereo balance, and noise level immediately accessible.

Laboratory Precision & Core Architecture

• 256-bit Xoshiro256++ Core: Dual independent 32-bit floating-point PRNG generators (256-bit state) producing White, Pink, and Brown fields with zero sample looping and true decorrelated stereo imaging (r < 0.005).
• Calibrated True RMS & Peak Telemetry: Dual 20-segment calibrated LED ladder meters providing instantaneous peak response and decaying peak-hold (-24 dB/s), calibrated directly to faceplate dB markings (-48 dBFS to 0 dBFS).
• Smart Standby Gating (0.0% CPU): Puts the DSP engine into zero-CPU standby with total silence whenever transport stops and the device is idle.

Technical Specifications

• Device Format: 2U Rack Extension (with full-function compact folded strip)
• Internal Processing: 32-bit floating-point DSP architecture
• Sample Rate Support: 44.1 kHz to 192 kHz native processing
• PRNG Engine: Dual 32-bit floating-point Xoshiro256++ (256-bit state, period 2^256 - 1, cross-correlation r < 0.005)
• Reference Calibration: -18.00 dBFS True RMS at unity
• Filter Topology: 4th-order cascaded Butterworth (24 dB/octave, Nyquist-linearized 2x polyphase oversampling, bit-exact bypass)
• Stereo Imaging: Discrete M/S matrix with constant-power width (0% to 200%) and True Stereo Balance Law (0 dB center, level-invariant)
• Rear Audio Connections: Stereo L/R Inputs (Thru Raw / Summing), Stereo L/R Outputs
• Rear CV Connections: Sequencer Pitch & Gate In, Gate Out Relay, Mod Wheel CV In, HPF CV In, LPF CV In, Level CV In (Dual VCA/Tremolo mode switch), Noise CV Out, S&H CV Out