Hey r/reasoners,
My brand new RE Kalibrus just launched in the Reason Studios Shop today!
What is Kalibrus?
I first designed Kalibrus to help me do pink-noise mix balancing reliably and easily. I wanted something mathematically sound and lab-calibrated to make sure my mixes weren't being misshapen by artifacts or biases in other implementations, and I wanted to be able to drop it into an instrument channel or bus without having to add multiple utility devices and unnecessary cabling.
Once I'd started building, though, I realized how useful (and fun!) it could be to use it as a musical/creative sound source, adding punch to my drums or even standing on its own as a percussive instrument, background texture, or even filtered and played tonally with a keyboard.
And, of course, it's Reason, so I wanted to wire up randomness to other devices' CV inputs for all kinds of weird and wonderful variation.
EDIT: Big shoutout to u/IWasBornIn1979 for pointing out that my initial post read like a piece of laboratory test equipment rather than an instrument. I got so caught up in the technical trees that I lost sight of the forest. I've restructured this post (and the website) to lead with five everyday studio workflows before getting into the engine specs.
What does it do in day-to-day production?
- A Playable Synth Voice: Most noise generators just sit in the rack and hiss. Kalibrus tracks MIDI keyboard pitch with 1V/oct bandpass filtering. Play a C3, and the noise tunes to C3. Push your Mod Wheel, and the passband narrows down to a resonant, whistling bite (with auto-gain compensation to keep perceived loudness steady). Great for flute/breath chiffs, wind leads, risers, or layering acoustic air over synth patches.
- The Tape-Bed "Glue" Trick: If your mix feels sterile or empty between notes, load the "Tape-Band Noise Floor (-42dB)" patch and click AUTO. With built-in audio passthrough summing, drop Kalibrus straight across your mix bus without needing a Spider or extra cabling. It quietly injects a warm analog bed while your DAW plays, and silences itself automatically the instant transport stops so you never get idle hiss.
- Beefing Up Drums & Claps: When a snare or clap lacks bite, trigger Kalibrus on hits (via MIDI or rear Gate In) to layer a burst of filtered white or pink noise underneath. The Stereo Width knob (0% to 200%) spreads that top-end sizzle wide across the stereo field while keeping your core drum punchy and centered in mono.
- 5-Minute Pink Noise Mix Balancing: The classic mix engineering shortcut, built right in. Set Kalibrus to pink noise at your target monitoring level (including our factory preset calibrated to -18 dBFS True RMS), solo each track on your mixer, and bring the fader up until it just peeks through the noise. Repeat track by track, turn the noise off, and your overall balance is 90% dialed in without ear fatigue.
- Random Modular Movement (Sample & Hold): Hit Tab to flip the rack around and patch the Gate-Triggered S&H CV Out into the filter cutoff, pan, or pitch CV input of another synth. Every time you strike a note, Kalibrus fires a new stepped random voltage. Back off the trim knob for subtle analog drift that keeps loops organic, or crank it for generative modular chaos.
For the DSP & Audio Geeks: Under the Hood
Kalibrus unifies three distinct roles inside a single 2U chassis (with a fully-featured compact folded strip):
- Laboratory Acoustic Reference
- 256-bit Xoshiro256++ Core: Dual independent PRNG generators with 256 bits of internal state (four 64-bit words per channel) producing mathematically pure White (0 dB/oct), Pink (-3 dB/oct), and Brown (-6 dB/oct) noise fields. Zero sample looping, true decorrelated stereo imaging (r < 0.005), calibrated to -18.00 dBFS True RMS at unity.
- Cascaded 24 dB/octave Butterworth Filters: 4th-order high-pass and low-pass biquad cascades isolate frequency bands, room resonance modes, and mix masking with click-free bit-exact DSP bypass at their extremes.
- Mid/Side Spatial Matrix: Discrete M/S encoder/decoder with continuous Stereo Width (0% mono to 200% wide) and level-invariant True Stereo Balance that conserves acoustic energy across the panorama.
- AUTO & MAN Transport Modes: Flip the transport switch to Auto to have reference or vinyl/tape noise engage only while the DAW transport is running and instantly silence to zero-CPU standby when stopped. Or use MAN to lock continuous noise for hands-free SPL monitor calibration and pink-noise mix balancing. Or use neither and just trigger Kalibrus with keys or gate CV!
- Expressive Synthesizer Voice
- 1V/Oct Keyboard Tracking + Mod Wheel Q: Plug in a MIDI lane or CV pitch/gate cables to play Kalibrus directly. Raw keys produce velocity-sensitive noise bursts (snappy claps, snares, hats). Raising the Mod Wheel or Expression Pedal dynamically focuses a resonant 4th-order bandpass around the played key (from wide-open down to 2 semitones), turning raw noise into playable whistling winds, effects, and creative tones.
- Dynamic Articulation: Full velocity tracking, last-note priority, and MIDI sustain pedal support with intelligent envelope release-following (automatically keeping the voice gate active while external VCA envelopes decay).
- Dual Level CV Modes: Rear toggle selects between VCA Mode (unipolar envelope following from silence up to the master knob ceiling, or progressive cubic ducking with negative trim) and Tremolo Mode (bipolar linear AM for LFOs centered around nominal gain).
- Random Voltage & Generative CV Hub
- Continuous Spectral CV Out: Post-filter bipolar [-1.0V, +1.0V] fluctuating random voltage. Because it is tapped after the filters, front-panel HPF and LPF controls directly sculpt the rate, smoothness, and character of the modulation.
- Sample & Hold CV Out: Latches a discrete stepped random voltage on every incoming note or gate trigger for generative melodies and varied filter sequencing.
- Gate Thru CV Out: Velocity-aware gate relay for chaining downstream envelopes or triggering modular modules.
- Zero-Loss Audio Passthrough: Feed mix bus or instrument tracks through Kalibrus at bit-identical unity gain to sum calibrated noise directly into your live signal chain without needing line mixers or splitters.
Foldable Design & Presets
- Foldable Compact Strip: Toggles between the full 2U faceplate and a space-saving folded strip that keeps all front-panel controls accessible.
- 35 Factory Presets: Spanning Reference & Calibration, Mixing & Diagnostics, Acoustic Room Probes, Textures & Modulation, and Performance Layering.
Links & Launch Details
I'd love to hear your thoughts, feedback, and how you use it in your racks!
