Audio Reactive Laser Visuals

Modulaser can react to live audio from any input device (a USB microphone, an audio interface, or a virtual loopback from your computer) or to the song on the timeline's audio track. The audio modulator turns incoming sound into a 0–100% signal you can route to any parameter, so shapes pulse with the kick, colors shift with the melody, or geometry physically deforms to match the waveform.

Multi-channel interfaces are supported. Waveform mode reads the channel you pick, while Loudness and Spectrum follow the whole input.

Quick Start

This is the fastest way to make a clip react to music:

1. Open Settings and select an audio input device in the Devices tab.
2. Add an Audio Input modulator from the modulator panel.
3. Set the mode to Loudness.
4. Drag the modulator's circle onto a Scale knob, or onto Light (Value in HSV mode) for a brightness reaction.
5. Play audio and adjust Gain until the signal moves clearly.
6. Adjust Fall to control how quickly the reaction fades.
7. Use Gate in Settings if background noise keeps triggering the modulator.

Setting Up an Audio Device

Open Settings from the menu (CmdCtrlCmd/Ctrl + ,) and click the Devices tab. Select your audio input device from the Device dropdown, or Timeline audio track to react to the song on the timeline. Select "None" to disconnect.

The selected source is shared by all audio modulators and Audio Input nodes across all clips. Each modulator or node picks which channel to read from. Your selection persists across sessions.

Timeline Audio Track as a Source

Timeline audio track analyzes the audio clips on the timeline at the playhead instead of a live input. No loopback device, no latency. Clip volume, track volume, and mute apply just as they do in playback.

Modulation follows the playhead: it holds while paused, lands on the right values when you scrub or jump, and goes silent when the timeline stops. The same playback always produces the same modulation, so what you rehearse is what you get on show night.

Gate & Limit

When a source is connected, each input channel shows a live level meter with two controls:

• Gate (0–100%, default 0%): signal below this level is silenced, and the rest is stretched to fill 0–100%. Use it to cut background noise so quiet moments produce zero modulation.
• Limit (0–100%, default 100%): input at or above this level counts as full scale. Lower it to make a quiet source reach 100% sooner. To attenuate a loud source, lower Gain instead.

Both appear as vertical markers on the level meter. These settings apply globally, so every modulator reading from that channel sees the gated and limited signal.

Adding an Audio Modulator

Click the + button on the modulator panel and select Audio Input. The modulator starts reading from the selected device immediately.

Channel

If your device has multiple inputs, use the channel selector to pick which one a Waveform modulator reads. Loudness follows the loudest channel and Spectrum analyzes a mix of all channels, so neither isolates a single input. The channel also decides which channel's Gate and Limit apply.

Audio Modes

The audio modulator has three output modes:

Loudness: Envelope-followed peak amplitude. Produces a single value per frame that rises with loud transients and decays smoothly. Best for beat-reactive effects like pulsing size, brightness, or scale.

Spectrum: FFT spectrum across a configurable frequency band. A live FFT sits below the mode selector with a draggable range selector. Drag the low and high handles to choose a band (e.g. 20–200 Hz for bass, 5–15 kHz for hi-hats), or drag the range itself to slide both handles together. The band is spread across the shape: the low end maps to the start and the high end to the end, so targets that vary per point, like a shape's Scale X or Hue, get a spectrum-shaped profile. Targets that read one value per frame follow the level at the low edge of the band.

Waveform: The rectified audio waveform (always 0 or above) mapped across the shape's points. Each point on the laser shape samples a different moment from a rolling audio buffer, so the shape physically deforms to match the waveform. Creates oscilloscope-like effects and audio-driven geometry.

Controls

Spectrum Visualization

Every audio modulator shows a live spectrum display regardless of which mode you're using. The bars reflect that modulator's own gain and fall settings. The interactive range selector appears below the bars in every mode: bars inside the selected range are highlighted, bars outside are dimmed. The range shapes Spectrum and Waveform output.

Routing Audio to Parameters

Drag the modulator's circle onto a parameter knob to route it. Click the capsule that appears on the knob to adjust the routing:

• Amount: how far the audio moves the parameter. Negative values push it the other way.
• Invert: flips the modulator's shape before the amount applies. An inverted Loudness routing sits high during quiet passages and drops back to the knob's value on every hit.

Hover the capsule to see the value the parameter is using right now. Hover a modulator's circle to outline every knob it drives.

Recipes

Kick pulse: Set the modulator to Loudness and route it to a Scale knob or to Light (Value in HSV mode). Keep Fall short for a tight pulse, or increase it for a smoother swell.

Bass color shift: Set the modulator to Spectrum, drag the frequency range to the low end, and route it to Hue or Sat. This lets the bass move color without the whole mix driving the reaction.

Hi-hat sparkle: Use Spectrum with a high-frequency range and route it to Light or a small amount of Scale. Keep the routing amount subtle so the reaction adds texture instead of flicker.

Oscilloscope geometry: Set the modulator to Waveform and route it to an oscillator's Level or a shape parameter that changes geometry. Short Window values show tighter waveform detail; longer values spread more audio over the shape.

Spectrum analyzer: Pick the Spectrum Bars shape in a Simple layer. Modulaser adds a Spectrum-mode audio modulator routed to the bars' Base knob, so they react straight away. Set the frequency range, Gain, and Fall on that modulator.

Audio Input Node

The same audio functionality is available as an Audio Input node in NodeGraph layers, with the same parameters (mode, channel, gain, fall, frequency range, window). The node outputs a scalar from 0 to 1, multiplied by Gain.

In Spectrum and Waveform modes, the output varies per point along the shape's position, so different parts of the shape respond to different frequencies or waveform positions. The node lets you wire that signal into any port, combine it with math nodes, or drive Gain and the frequency range from other signals. Wire a Spectrum-mode Audio Input into a Spectrum Bars node's Level input to get a bar spectrum analyzer, with the frequency range spread across the bars.

Audio Input nodes inside an output group's effect graph don't receive audio and always output 0.

Routing Computer Audio into Modulaser

If you're playing audio on the same computer running Modulaser, it's better to route the audio directly instead of picking it up through a microphone. Direct routing means zero distortion and no delay.

If the song is on the timeline's audio track, skip the virtual device and select Timeline audio track as the source.

macOS

Use Loopback (paid) or Blackhole (free).

Blackhole works but takes some configuration. Follow the setup instructions including the Audio MIDI Setup step. Once configured, go to System Settings > Sound > Output and select "Multi-Output Device", then open Modulaser's device settings and select "Blackhole (2ch)".

Windows

Use VB-Cable (free). After installation, open Modulaser's device settings and select "CABLE Output".

FAQ