Every Novus visualizer engine analyses your audio in real time using FFT (Fast Fourier Transform) frequency analysis. This guide explains how that works and how you can shape the reactivity to match your music.
How Audio Analysis Works
When you upload an audio file and press play, Novus uses the Web Audio API to break the audio signal into 256 frequency bins in real time. These bins span from sub-bass (around 20 Hz) up to the upper treble range (around 20 kHz).
Each visualizer engine reads these frequency values every frame and maps them to visual properties — bar heights for Spectrum, particle burst intensity for Particles, terrain height for Terrain, and so on.
Sensitivity Controls
The Sensitivity slider in the Reaction Style section controls how aggressively the visualizer responds to volume changes. A higher sensitivity means even quiet passages produce strong visual movement; a lower value requires louder audio to trigger the same movement.
For music with a wide dynamic range (orchestral, classical, acoustic) try a higher sensitivity setting. For loud and compressed tracks (EDM, hip-hop) a lower sensitivity prevents the visualizer from constantly clipping at maximum.
Tips
- →Start with sensitivity at 1.0 and adjust in 0.2 increments until the visualizer feels balanced.
- →If the visualizer barely moves during quiet passages, increase sensitivity. If it's always at maximum, decrease it.
Frequency Focus
The Frequency Focus dropdown lets you narrow the audio analysis to a specific frequency band: Full Spectrum, Bass, Mid, or Treble.
Bass focuses on kick drums and low bass lines (20–250 Hz). Mid captures vocals and guitar (250 Hz–4 kHz). Treble highlights hi-hats and synth highs (4 kHz+). Full Spectrum uses the entire range and is the default.
Tips
- →For hip-hop and bass-heavy music, try Bass focus so the visualizer pulses with the kick drum.
- →For vocal-focused lyric videos, Mid focus makes the visualizer react to the singer's voice.
Response Styles
The Response Style selector changes how the visualizer smooths or sharpens its reaction to audio peaks: Balanced is smooth and natural; Smooth averages more frames together for a flowing look; Pulse creates sharp spikes on transients; Burst produces explosive reactions to loud hits.
Pulse and Burst work best with percussive music. Smooth is ideal for ambient and cinematic audio.