Search for a water eject sound and one number comes up again and again: 165 Hz. It is a good number, but it is not the only one that works, and the reason it works is more useful to know than the number itself.
Where 165 Hz comes from
When people recorded and measured the tone an Apple Watch plays to clear its speaker, it came out at roughly 165 Hz. Apple has never published the figure, but the measurement has been repeated often enough that most eject apps and shortcuts copied it. It became the default because it was shown to work on a very small speaker.
Why low tones push water out
A speaker makes sound by moving a thin diaphragm back and forth. How far it moves depends on the pitch. For the same loudness setting, a low note makes the diaphragm travel much further than a high one. A high note is a tiny, fast flutter. A low note is a slow, deep push.
Water on the mesh is held by surface tension, and it takes a physical shove to break it loose. Low tones give the biggest shove. That is why eject sounds live at the bottom of what a phone speaker can play, and why the sound is an ugly buzz rather than something pleasant.
The useful range
| Frequency | What happens |
|---|---|
| Below 100 Hz | Most phone speakers cannot reproduce it. You hear almost nothing and little moves. |
| 130–200 Hz | The working range. Large diaphragm movement that the speaker can still produce loudly. |
| 200–500 Hz | Less movement, but useful for very small drivers such as earbuds and smartwatches. |
| Above 1,000 Hz | Too little movement to shift water. High tones are only useful for the earpiece, which cannot play low notes at all. |
Why pulsing beats a steady tone
A steady tone sets up a regular motion, and a droplet can settle into moving with it. Switching the tone on and off several times a second, or nudging the pitch up and down, keeps jolting the droplet from a standstill. Each restart is a small shock. This is why the Standard mode on this site pulses a 155 Hz tone rather than holding it.
How to find the best frequency for your phone
Every speaker has a pitch where it moves most easily. You can find yours in a minute:
- Open the water eject tool and start it in Standard mode.
- Slowly drag the pitch slider from 100 Hz up to 300 Hz.
- Listen and feel for the point where the buzz gets noticeably louder and the phone vibrates most in your hand.
- Leave the slider there for the rest of the run.
On most phones this lands somewhere between 140 Hz and 200 Hz. For anything unusual, such as earbuds or a watch, the frequency generator covers the full range from 20 Hz to 20,000 Hz.
Does the waveform matter?
A little. A sine wave is the smooth, pure version of a tone. Sawtooth and square waves contain the same note plus sharper edges, which adds extra jolts. They sound harsher and can help with stubborn water, which is what the Deep mode uses. Start with sine and move up only if you need to.