Explosion

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What Is This Sound?

This is a synthesized explosion sound effect created entirely using web audio synthesis — no recordings of actual explosions required. The deep, rumbling blast you hear is generated in real-time by your browser through shaped noise and dynamic filtering, producing a convincing detonation that works for games, films, and multimedia projects.

Explosions are one of the most complex natural sounds to reproduce, involving simultaneous shockwave propagation, debris scattering, and pressure wave reflections. This synthesized version captures the essential perceptual qualities — the sharp initial crack followed by a decaying low-frequency rumble — using surprisingly simple building blocks.

How Is the Explosion Sound Created with Code?

The explosion sound uses white noise shaped by a sweeping lowpass filter and amplitude decay. Here is how to build it with Tone.js:

Step 1: Generate White Noise

White noise contains energy at all frequencies equally, providing the raw broadband energy that forms the basis of the explosion:

const noise = new Tone.Noise("white");

Step 2: Apply a Sweeping Lowpass Filter

The key to a realistic explosion is spectral energy that starts broad and shifts rapidly to low frequencies. We achieve this with a lowpass filter that sweeps from 1000 Hz down to 20 Hz over one second:

const filter = new Tone.Filter({
  type: "lowpass",
  frequency: 1000,
  rolloff: -24,
});

filter.frequency.rampTo(20, 1);

Step 3: Shape the Amplitude Envelope

The initial blast is loud, then decays exponentially. We use a gain node that drops from 0.5 to near-silence over one second:

const gain = new Tone.Gain(0.5);
gain.gain.rampTo(0.01, 1);

noise.connect(filter);
filter.connect(gain);
gain.toDestination();

noise.start();

Step 4: Signal Chain

The complete signal path is: White Noise → Lowpass Filter (1000Hz → 20Hz sweep) → Gain (0.5 → 0.01 decay) → Speakers

The Science Behind the Explosion Sound

How Real Explosions Produce Sound

A real explosion generates a rapid expansion of gas that creates a shockwave — a sudden pressure discontinuity that propagates outward at supersonic speeds. This shockwave initially contains energy across the entire audible spectrum (and beyond), which is why white noise is the correct starting point for synthesis.

As the shockwave propagates, high-frequency energy dissipates faster than low-frequency energy due to atmospheric absorption and geometric spreading. This is exactly what our sweeping lowpass filter models: the gradual removal of high frequencies over time, leaving only the deep rumble.

Spectral Energy Decay

The frequency content of an explosion changes dramatically over its duration. In the first few milliseconds, energy is distributed broadly — you hear a sharp crack. Within 100 milliseconds, the spectrum shifts heavily toward low frequencies below 200 Hz. By one second, almost all remaining energy is below 50 Hz, perceived as a subsonic rumble. Our filter sweep from 1000 Hz to 20 Hz replicates this natural spectral decay pattern.

Frequency Spectrum

Common Uses

• Game Sound Design — Explosions, grenades, rocket impacts, destructible environments, and boss defeat sequences
• Film & Video Post-Production — Layered with other elements to build complex explosion sound design for action sequences
• Trailer & Cinematic Audio — Dramatic impact moments in movie trailers, game cinematics, and promotional videos
• Music Production — Layered as a percussive impact element in electronic, cinematic, and hybrid music genres
• Presentations & Motion Graphics — Punctuating transitions or dramatic reveals in animated infographics
• Prototyping — Instant placeholder explosion audio for game jams and rapid development cycles

Technical Details

Frequently Asked Questions

Can I use this explosion sound in my game?

Yes. The sound is generated by code in your browser. The downloaded WAV file is completely free to use in any personal or commercial project, including published games and films.

How do I make the explosion sound bigger?

Increase the initial filter frequency to 3000 Hz or higher for a more aggressive initial crack. You can also layer two instances with slightly different filter sweep rates — one fast (0.3s) for the initial blast and one slow (2s) for the rumbling tail. Adding reverb in post-processing can simulate the environment the explosion occurs in.

Can I make it sound more like a small firecracker?

Yes. Shorten the overall duration to 0.2 seconds, start the filter at 2000 Hz, and use a faster decay. Small explosions have less low-frequency content and decay much faster than large ones.

Why does it sound different from recorded explosions?

Recorded explosions capture complex environmental reflections, multiple debris impacts, and air pressure dynamics that are difficult to replicate with a single noise source. This synthesized version captures the core perceptual essence. For more realism, layer it with short burst textures and add convolution reverb to simulate environmental reflections.