What is 30 Hz?
30 Hz is a tone in the sub-bass region — the deepest bass, felt as much as heard. Its nearest musical note is B0 (about -49 cents away), and its sound wave is roughly 11.433 m long in air. Because it is a pure sine wave, it contains only this one frequency with no harmonics, which is exactly what you want for testing and calibration.
30 Hz is deep sub-bass — the rumble of a pipe organ pedal or a movie explosion. Full-range subwoofers should reproduce it cleanly with no port chuffing or distortion.
What you can use a 30 Hz tone for
- Testing subwoofer and speaker bass extension
- Finding room resonances and rattles
- Setting a subwoofer crossover and level
Can you hear 30 Hz?
Most people feel this more than they hear it as a pitch, and many speakers and earbuds cannot reproduce it — if you hear nothing, it is usually your hardware, not your ears. If you are testing your hearing, do it at a modest, consistent volume in a quiet room and compare both ears. For a full walkthrough, see our at-home hearing range test guide. Remember this is a self-check, not a medical diagnosis.
Frequently asked questions
What is a 30 Hz test tone?
A 30 Hz test tone is a pure sine wave vibrating 30 times per second. It falls in the sub-bass range (the deepest bass, felt as much as heard) and its nearest musical note is B0. You can play it instantly above to test audio equipment or your hearing.
Can everyone hear 30 Hz?
Most people feel this more than they hear it as a pitch, and many speakers and earbuds cannot reproduce it — if you hear nothing, it is usually your hardware, not your ears.
What note is 30 Hz?
The nearest equal-tempered note to 30 Hz is B0 (about -49 cents away).
Is it safe to play 30 Hz?
Yes, at a sensible volume. Start low and raise it gradually. Very loud tones of any frequency can harm hearing or, at very low frequencies, over-drive speakers — so keep levels comfortable and take breaks.
Explore more test tones
Need a different pitch? Browse every test-tone frequency, or jump to a nearby one:
You can also use the full test tone generator for frequency sweeps, speaker balance and polarity checks, and the tinnitus matcher.