What is 100 Hz?
100 Hz is a tone in the bass region — low bass you feel in your chest. Its nearest musical note is G2 (about +35 cents away), and its sound wave is roughly 3.43 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.
100 Hz is the boundary many small speakers can just about reach. It is a common crossover point between a subwoofer and satellite speakers, which makes it handy for level-matching a 2.1 system.
What you can use a 100 Hz tone for
- Checking speaker warmth and 'boominess'
- Room-mode and standing-wave hunting
Can you hear 100 Hz?
Almost everyone can hear this, but small laptop and phone speakers often roll off down here, so use headphones or a subwoofer for a fair test. 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 100 Hz test tone?
A 100 Hz test tone is a pure sine wave vibrating 100 times per second. It falls in the bass range (low bass you feel in your chest) and its nearest musical note is G2. You can play it instantly above to test audio equipment or your hearing.
Can everyone hear 100 Hz?
Almost everyone can hear this, but small laptop and phone speakers often roll off down here, so use headphones or a subwoofer for a fair test.
What note is 100 Hz?
The nearest equal-tempered note to 100 Hz is G2 (about +35 cents away).
Is it safe to play 100 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.