What is 50 Hz?
50 Hz is a tone in the bass region — low bass you feel in your chest. Its nearest musical note is G1 (about +35 cents away), and its sound wave is roughly 6.86 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.
50 Hz is close to the mains-hum frequency in much of the world (and a harmonic of 60 Hz regions). It is deep bass you can feel — useful for setting subwoofer level and checking for rattles in a room.
What you can use a 50 Hz tone for
- Testing subwoofer and speaker bass extension
- Finding room resonances and rattles
- Setting a subwoofer crossover and level
Can you hear 50 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 50 Hz test tone?
A 50 Hz test tone is a pure sine wave vibrating 50 times per second. It falls in the bass range (low bass you feel in your chest) and its nearest musical note is G1. You can play it instantly above to test audio equipment or your hearing.
Can everyone hear 50 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 50 Hz?
The nearest equal-tempered note to 50 Hz is G1 (about +35 cents away).
Is it safe to play 50 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.