Online Tone Generator
Generate pure frequencies for tuning instruments, science experiments, or testing audio equipment.
How to use:
- Sine Wave: Smooth, pure sound. Best for testing subwoofer bass or checking for room resonance.
- Square Wave: Harsh, buzzy sound. Used for signal processing tests.
- Sawtooth/Triangle: Richer harmonics. Useful for synthesis and electronic music tuning.
Warning: High frequency tones (above 10kHz) can be very piercing. Keep volume low.
What is a tone generator and why use one?
A tone generator outputs a pure sine wave at a specific frequency, measured in hertz (Hz). Pure tones are the simplest possible sound — every other sound is built from layered combinations of them. Generating one at a known frequency lets you isolate problems that real-world music or speech masks: a buzz at 60 Hz, a resonance at 200 Hz, a missing high-frequency response above 12 kHz.
Common uses for a browser-based tone generator include:
- Finding the resonant frequency of a cabinet or panel — sweep slowly between 50 and 300 Hz and listen for a sudden increase in apparent loudness, which is usually a panel vibrating sympathetically.
- Checking the bass response of a subwoofer — most consumer subwoofers struggle below 35 Hz. Play 20 Hz, 25 Hz, 30 Hz, and 40 Hz in sequence and listen for which is the lowest you can clearly hear.
- Locating room nulls and modes — at low frequencies, room dimensions create standing waves that boost some frequencies and cancel others. Play a steady tone at 80 Hz and walk around the room — you'll hear the volume rise and fall dramatically.
- Confirming the upper limit of your hearing — adult hearing typically rolls off around 14–17 kHz, with younger listeners able to hear up to roughly 20 kHz. Most adults over 40 cannot hear above 15 kHz.
- Testing tweeters — tweeters fail silently. A clean 8 kHz or 10 kHz tone immediately tells you whether a tweeter is working at all.
A quick reference: frequencies and what they sound like
- 20–60 Hz — sub-bass. Felt as much as heard. Below most speakers' useful range.
- 60–250 Hz — bass. Kick drums, bass guitar fundamentals, male vocal warmth.
- 250 Hz–2 kHz — midrange. Most musical fundamentals and vocal intelligibility live here.
- 2–6 kHz — presence. Adds clarity and bite to vocals and guitars.
- 6–20 kHz — air. Cymbal shimmer, sibilance, perceived "openness".
A safety note about test tones
Pure sine waves are fatiguing to listen to and can damage tweeters and hearing if played too loud. Always start with the volume turned down and increase gradually. If you're testing speakers near their power limits, keep the tone short (a few seconds at a time) — sustained high-power sine waves are exactly the signal that destroys voice coils.