Audio Mapping

Arkestra includes a real-time audio analysis engine (DSP Processor) that detects drums and extracts frequency band energy from any audio input. The results are available as modulation sources.

Audio sources available

Arkestra has 3 configurable detector ranges, each mapping to a frequency band and onset detector:

Source	Default detector	Description
Audio Range 1	Kick	Low-frequency onset detection (~45–296 Hz)
Audio Range 2	Snare	Mid-frequency onset detection (~1571–4146 Hz)
Audio Range 3	Hihat	High-frequency onset detection (~4–12 kHz)

Each range’s frequency band, threshold, and input channel can be tuned in the Audio tab.

Multi-channel input

When using a multi-channel audio interface, each detector can be independently routed to a specific input channel — or a sum of two channels. The Channel selector appears in each range’s settings row inside the Audio tab.

The channel picker shows a live level meter next to each channel, so you can immediately see which channels carry signal — handy when connecting a mixer or multi-channel interface. With the picker open, step through channels with the up/down arrow keys; the selection applies instantly. Press Return or Escape to close.

This means you can, for example, route Range 1 to kick on channel 1, Range 2 to snare on channel 3, and Range 3 to a summed stereo mix of channels 1+2 — all simultaneously.

Setting the audio input

Open the Audio tab (waveform icon) in the right panel to select your input device and configure input channels.

Live frequency spectrum

The audio panel shows a live full-spectrum frequency bar with peak-hold indicators and a highlight overlay for the selected band. It uses ~60 third-octave bands for an EQ-style look, so you can see the signal you’re mapping against at a glance.

• Drag on the bar to move the active band’s centre frequency.
• ⌘-drag to adjust the band’s width around its current centre.

The display pauses automatically when the panel is scrolled offscreen or hidden, so it costs nothing when you’re not looking at it.

Mapping audio to a parameter

Right-click any float parameter → Map to Audio → [Range 1 / Range 2 / Range 3]

You can also pick the Audio tile in a parameter’s mapping panel. The panel has three tabs: Bands (one tab per detector band), Rhythm (Kick / Snare / Hihat), and Energy (how full the track is). Click a tab to switch.

Rhythm has two styles:

• Envelope follows the selected drum’s hit envelope, so the parameter jumps on each hit and decays.
• Dominant works like a mute group on an MPC. Whichever drum hit last owns the group, and the parameter is fully on only while your selected drum owns it. Map an effect’s Dry/Wet to Dominant → Kick: the effect is on while the kick is playing, and turns off as soon as a snare or hi-hat takes over. There is one mute group shared by every Dominant mapping, so exactly one drum is ever active across all of them. In Dominant, each drum tab has a checkbox that sets who is in the group. Changing a checkbox changes the group for every mapping. Unchecked drums are ignored completely: with only Kick and Snare checked, hi-hats can’t take the group away from the kick, and a mapping set to an unchecked drum stays off. If two drums in the group hit at the same moment, the stronger hit wins. After about 2 seconds with no hits from any drum in the group, the group goes quiet and every Dominant mapping turns off. Dominant works on sliders and toggles, and the meter shows which drum owns the group right now.

Energy tracks the shape of a drop rather than plain loudness. It learns what the track sounds like at full power (bass, kick and the whole spectrum in), then measures how close the music is to that right now. It drains when the kick drops out or the bass is filtered away in a breakdown or build-up, even if the build is just as loud, and jumps straight back to full the moment the drop lands. Rhythm analysis must be enabled for Energy to move.

Arkestra remembers the last mode and drum you picked, so the next parameter you map to Audio opens on the same choice. Rhythm always opens in Envelope style.

The parameter will now respond to that detector’s output. Adjust Depth and Min/Max range in the parameter’s modulation inspector to tune the response.

Master gain

The audio Master Gain sits in the signal output stage — it scales the analysed signal after the raw input path, and its control lives in the audio panel. It syncs to the detectors every frame, so gain changes apply immediately.

Envelope settings

Each drum detection output has:

• Attack — how quickly the signal rises on a detected onset
• Release — how quickly it decays after the onset
• Threshold — sensitivity (higher = fewer detections)

Shorter attack + shorter release = tight, punchy response. Longer release = lingering effect.

Audio FX — hosting Audio Unit plugins

The FX tab inside the Audio panel hosts Audio Unit effects (reverbs, delays, compressors) on your audio. It works on both the External Input and Local Audio sources. Every plugin parameter becomes a normal Arkestra parameter, so a reverb’s mix and a video effect’s intensity can ride the same global macro, LFO, MIDI CC, or audio band.

Add an effect with Add Audio Effect and pick from the Audio Units installed on your Mac. AUv3 plugins load out of process, so a plugin crash can’t take Arkestra down with it. VST plugins are not supported — macOS has no system VST host, and virtually every commercial plugin also ships an Audio Unit build.

Each rack row gives you:

• Bypass — toggles the plugin in place, with no audio dropout
• Open plugin interface — the plugin’s own window, floating above Arkestra
• Disclosure arrow — the full parameter list, each row mappable like any other parameter
• Drag to reorder — the rack processes top to bottom

Turning a knob in the plugin’s own window writes back into the matching Arkestra parameter, as long as that parameter isn’t mapped. Once it’s mapped, the mapping is the authority.

Monitoring (External Input only)

On Local Audio the effects are simply in the playback path — you hear them as you go, with nothing to configure.

On External Input Arkestra isn’t making sound at all by default, so hearing the effects needs an explicit Monitor toggle and a mappable Monitor Level. It’s off by default.

macOS usually runs one device for both directions, so processed audio comes back out of the input device’s outputs — pick an interface that has both. Monitoring is blocked for System Audio capture: routing it back out would feed straight back into the tap.

Monitoring being unavailable doesn’t stop the effects. They still process, and recordings still capture them — you just can’t hear them live.

Analysis stays dry

Drum detection and band analysis always read the signal before the FX chain. A reverb smears transients, which would wreck kick and snare detection — so the analysis path never sees the wet signal, on either source.

Recording

When the FX rack is live, screen recordings capture the processed audio. With an empty rack, recording behaves exactly as before.

Your rack — plugin order, bypass states, parameter mappings, and each plugin’s own preset state — is saved with the project. If a plugin isn’t installed when the project opens, its row is marked MISSING and nothing is discarded; install the plugin and reopen the project to get it back.

Tips

• Use Range 1 (Kick) for sharp, percussive parameter hits on the kick
• Use Range 3 (Hihat) for tight 16th-note movement
• Map a parameter to an LFO (slow sine) and combine it with an audio source (short release) using + (see Combining signals) for rhythmic pulses riding a slow wave