WavexWhat frequency removes water from a phone speaker?
A low tone in the 150–200 Hz range, most often around 165 Hz, works best for pushing water out of a phone speaker. Low tones make the speaker membrane travel further than high ones, which moves droplets through the grille, while tones far below that range are barely reproduced by a small phone speaker. Play it at full volume with the speaker facing down for 10 to 30 seconds, and repeat if needed. Ultrasonic tones can't help: phone speakers can't produce them.
Why a low tone moves water
A speaker pushes air by moving a thin membrane in and out. To play the same loudness, a lower note needs a bigger movement than a higher one. That's why bass makes a speaker cone visibly shake while a whistle doesn't. When water sits in front of a phone speaker, those bigger movements push and pull on the droplets and shove them out through the grille.
It's the same idea Apple uses on Apple Watch: when you turn off Water Lock, the watch plays a sequence of sounds to clear water from its speaker.
Why around 165 Hz
There's a practical limit at the low end. A phone speaker is tiny, so it can barely reproduce deep bass: below roughly 100 Hz most of the sound simply isn't there. Water eject tools therefore aim just above that, where the speaker still moves a lot but can still play the tone properly. Around 165 Hz has become the most common choice.
Because speakers differ between iPhone models, a tone that sweeps a little up and down around the target is more likely to hit the point where your speaker moves most. Wavex sweeps around 165, 175 or 185 Hz depending on whether you choose Light, Medium or Heavy.
| Tone range | What a phone speaker does | For water? |
|---|---|---|
| Below about 100 Hz | Barely reproduces it | Weak |
| About 150–200 Hz | Large membrane movement, plays cleanly | Best range |
| About 1–5 kHz | Small movement, sounds loud to the ear | Little effect |
| Above about 20 kHz (ultrasonic) | Can't produce it at all | No effect |
What about ultrasonic speaker cleaners?
Some apps describe themselves as "ultrasonic". Ultrasound is above about 20 kHz, beyond what people can hear, and phone speakers and the audio system that drives them aren't built to play it. An app can't turn your iPhone speaker into an ultrasonic cleaner. What actually helps is an audible low tone.
How loud and how long
- Volume: all the way up. A quiet tone barely moves the membrane.
- Position: speaker facing down so gravity helps the water out.
- Length: 10 to 30 seconds per session, repeated two or three times if the sound is still muffled.
- Comfort: don't hold the speaker against your ear while it plays, and lower the volume a little if you hear rattling.
You can also play a tone yourself: the tone generator in Wavex covers 20 Hz to 20 kHz and has a 165 Hz preset.
Play the right tone to clear water
- Disconnect headphones. Make sure no Bluetooth headphones or speakers are connected, so the tone plays from the iPhone.
- Volume to maximum. Press the volume-up button until the volume is all the way up.
- Speaker facing down. Place the iPhone face down on a cloth so the speaker points at the floor.
- Play a tone around 165 Hz. Start a water eject session or set a tone generator to about 165 Hz for 10 to 30 seconds.
- Repeat if needed. If the sound is still muffled, play it two or three more times and let the iPhone air-dry.
Questions and answers
Is 165 Hz the only frequency that works?
No. Anything in roughly the 150–200 Hz range works similarly. 165 Hz is simply the most widely used value, and a slight sweep around it suits different speakers.
Would a higher frequency be stronger?
No. Higher tones sound louder to the ear but move the speaker membrane less, so they push less water.
Do ultrasonic water eject apps work?
Phone speakers can't produce ultrasound, so a true ultrasonic tone can't come out of an iPhone speaker. What helps is an audible low tone.
Can a 165 Hz tone damage the speaker?
Played through the iPhone's own audio system at a normal maximum volume, it's an ordinary sound. If it rattles or distorts, lower the volume slightly.
Sources
- Apple Support: How to use Water Lock and eject water from your Apple Watch
- Apple Support: About splash, water and dust resistance of iPhone