Tone generator
Play any frequency from 20 Hz to 20 kHz in your browser. Drag the slider or type an exact value. Useful for testing speakers, checking your hearing range, or picking a cleaning frequency by hand.
Ready. Lower your volume before playing high frequencies.
Start with the volume low. High frequencies do not sound as loud as they are, which makes them easy to overdo. Bring the volume up gradually and never hold a speaker against your ear while sweeping.
What the different ranges are for
| Range | What it is | Useful for |
|---|---|---|
| 20–60 Hz | Sub-bass — felt more than heard | Testing subwoofers. Phones cannot reproduce this. |
| 60–150 Hz | Bass | Deep cleaning cycles, testing laptop and portable speakers. |
| 150–250 Hz | Low mids — where phone drivers wake up | Water ejection. 165 Hz sits here. |
| 250–500 Hz | Mids | Dust and lint removal. |
| 500 Hz–2 kHz | Upper mids — where voices live | 1 kHz is the standard audio reference tone. |
| 2–8 kHz | Presence — where the ear is most sensitive | Checking for rattles and distortion. |
| 8–20 kHz | Treble and air | Hearing-range checks. Keep the volume low. |
Choosing a waveform
Sine is a single pure frequency with nothing else in it. Set it to 165 Hz and 165 Hz is genuinely all that comes out. This is what you want almost always, and it is what every cleaning mode on this site uses.
Square contains the fundamental plus every odd harmonic above it. It sounds dramatically harsher and noticeably louder at the same nominal setting, because there is far more total energy in it. That extra energy can be useful for shifting stubborn debris, but it is also much harder on a small driver and much less pleasant to be near.
Triangle is a gentler relative of the square wave, with harmonics that fall away quickly. Sawtooth contains every harmonic and is the brightest and buzziest of the four.
Why your phone goes quiet below 150 Hz
Set the generator to 40 Hz on a phone and you will hear almost nothing, even at maximum volume. Nothing is broken — it is a physical limit.
Producing a low frequency means moving a lot of air slowly. The amount of air a speaker can move is set by the area of its cone multiplied by how far that cone can travel, and a phone driver is perhaps a centimetre across with under a millimetre of travel. There is simply not enough displacement available to make meaningful sound at 40 Hz.
Most phone speakers start producing usable output somewhere around 150 to 200 Hz and get steadily more efficient above that. This is precisely why 165 Hz works so well as a cleaning frequency — it is about as low as you can go while still getting real cone movement out of a phone, which is the useful combination.
If you are here to clean a speaker
Use the main tool instead. Holding one fixed frequency is less effective than sweeping, because a fixed tone can settle into a standing wave that leaves parts of the chamber barely moving. The cleaning modes sweep across a range and pulse, which covers the whole chamber and delivers repeated shocks rather than steady vibration.
Frequently asked questions
What frequency should I use to clean a speaker?
Around 165 Hz for water and 200 to 400 Hz for dust. If cleaning is what you are here for, the dedicated Fix My Speaker tool handles the sweeping and timing automatically, which works better than holding one fixed frequency.
Which waveform is best?
Sine for almost everything. It is a single pure frequency with no harmonics, so what you hear is exactly what you set. Square and sawtooth waves add a stack of harmonics on top, which makes them sound much harsher and louder at the same nominal volume — useful if you want maximum energy, unpleasant otherwise.
Why can I not hear low frequencies on my phone?
Because your phone physically cannot produce them. A speaker that small cannot move enough air to reproduce anything much below 150 to 200 Hz at any real level. Set the generator to 40 Hz on a phone and you will hear almost nothing — that is normal physics, not a fault.
Can I use this to test my hearing?
You can get a rough sense of your high-frequency limit by sweeping upward until you stop hearing anything, and that upper limit does drop with age. But it is not a hearing test — your speakers, your room and your volume setting all affect the result far more than your ears do. See an audiologist for anything that matters.
Is it safe to play high frequencies loudly?
Not at high volume, no. Frequencies above about 8 kHz can be uncomfortable and are a genuine hearing risk at sustained high levels, and because they are less obviously loud than mid frequencies it is easy to overdo it. Start quiet, and never hold a speaker to your ear while sweeping.
Will this damage my speakers?
Not at normal volume. What does put a speaker under strain is a sustained tone at maximum volume for a long time — a continuous sine wave is a harder load than music, because music has peaks and gaps that let the voice coil cool. Keep it under a minute at high volume and there is nothing to worry about.