Every Audio Reactivity Control, Explained: Source, Dynamics, Attack and Beat Response

There is a specific kind of disappointment that hits when a visualizer technically reacts to your track but does not feel like it. Everything on screen swells and shrinks together, in time with nothing in particular, and no amount of dragging sliders seems to fix it. The usual reaction is to turn something up. The usual result is that it swells harder.

The fix is almost never one control. The Audio panel is a signal chain — a series of stages that each transform the last one's output before the number ever reaches the picture. Once you know the order, the panel stops being guesswork, because you can tell which stage is flattening your track and go straight there.

Stage 1 — Primary audio source

Primary audio source picks which measurement drives the engine. Three of the options are frequency bands — bass, mid and treble — and the rest are whole-signal measurements: rms (average loudness), peak (the loudest sample in the window), onset (how sharply the sound just changed), beat (how strongly a beat is landing right now) and bpm-phase (a smooth sweep that completes exactly once per beat).

This is the single highest-leverage control in the panel and the one most people never touch. A kick-driven house track wants bass. A vocal-forward pop mix usually reads better on mid, because the vocal is where the emotional movement lives and the bass is a steady four-on-the-floor that produces steady, boring motion. Hi-hat-heavy trap benefits from treble. And bpm-phase is the odd one out: it ignores loudness entirely and just sweeps in time, which is exactly what you want for motion that must stay perfectly metronomic regardless of how the mix is behaving.

Stage 2 — Audio contribution and Audio dynamics

Audio contribution caps how much of the visual the audio is allowed to control, from 0 to 1. At 0 the scene ignores your track and idles on its own motion; at 1 the audio drives it as hard as the engine allows. Most catalog scenes ship somewhere between 0.55 and 0.9, tuned per mode.

Audio dynamics is the one to reach for when a scene feels twitchy rather than under-reactive. Instead of scaling the signal, it scales the signal's movement around its resting level. At 1 you get the full swing of the track. At 0 the band holds steady, so the scene stays lit and present but stops jumping — the calm, constant look that suits an ambient or lo-fi backdrop where the visual should not compete with the music. Turning dynamics down is very different from turning contribution down: contribution dims the visual, dynamics only settles it.

Stage 3 — Sensitivity

Sensitivity is a straight gain stage from 0 to 3, applied after the routing above. It is the right control for a quiet master that is not driving the visual hard enough, or a brickwalled one that pins everything at maximum. Unlike source and dynamics, it changes nothing about what the visual responds to — only how much. Reach for it last, once the source is right.

Stage 4 — Audio attack and Audio release

These two are the reason a good visualizer feels musical rather than merely synchronized. Audio attack (in milliseconds) is how fast the visual rises when the sound gets louder. Audio release is how slowly it falls back when the sound goes away. Together they are an envelope follower, the same idea as a compressor's attack and release.

• Short attack, short release (say 10 ms / 80 ms) — snappy and percussive. Every hit registers. Great for drums, punishing on a sustained pad.
• Short attack, long release (20 ms / 600 ms) — hits land instantly then bloom outward and fade. This is the setting that reads as expensive on most material.
• Long attack, long release (300 ms / 1200 ms) — slow breathing. The visual follows the arrangement rather than individual hits. Ideal for ambient, cinematic and lo-fi.

If a scene looks jittery, the answer is usually a longer release, not less audio. Jitter is the visual falling all the way back to zero between hits; a longer release keeps it aloft so the next hit builds on the last.

The beat layer runs alongside all of it

Everything above describes a continuous signal. Beats are different: they are discrete events, and they get their own set of controls that add on top.

• Beat sync all — the master switch. Off, the scene runs purely on the continuous envelope and ignores beats entirely.
• Beat response — how hard every engine hits on each detected beat, 0 to 2.
• Pulse intensity — scales the beat pulse where it feeds spawn rates, element size and shake.
• Beat shake — a frame kick on each beat. A little is punchy; a lot is a music video from 2009. It settles between beats rather than jittering continuously.

Beat Sync Explained goes deeper on this half of the panel, including how to tell a genuine beat from a busy bassline.

Spectrum range: the control nobody expects to need

On the engines that draw the frequency spectrum — Spectrum, Bars, Radial, Bloom and Tunnel — Spectrum range decides how much of the frequency axis the visual actually spans. It defaults to 0.86 rather than 1 for a reason: the very top of the frequency range is near-silent air on most masters, so at 1 the right-hand slice of every bar field and ray fan barely moves. That dead tail is a common cause of the complaint that a spectrum looks smooth and similar all the way across. Pull the range down and the visible bars redistribute across frequencies your track actually contains.

A diagnostic order that works

When a scene is not reacting the way you want, work down the chain in order rather than poking at whatever slider is nearest:

1. Is it reacting to the right thing? Change Primary audio source. This fixes more problems than every other control combined.
2. Is it reacting too uniformly? Lower Audio dynamics for calm, or raise it for swing.
3. Is it reacting hard enough? Raise Sensitivity.
4. Does it feel twitchy or dead between hits? Lengthen Audio release.
5. Do the beats land? Raise Beat response; if beats feel absent entirely, confirm Beat sync all is on.
6. Does the spectrum look flat on one side? Lower Spectrum range.

Where to try this

Every control here appears in both editors, on the same engines, with the same names — the Classic editor groups them in the Audio panel, and Creator Studio exposes them per layer in the inspector. Load a track you know well, pick a busy section, and step through the chain in the order above. New to the engines themselves? Meet the Novus Visualizer Engines is the tour, and How Music Visualizers Work covers the theory these controls sit on top of.