What to listen for during the sweep
A healthy speaker changes pitch smoothly and stays roughly as loud across the range. Faults announce themselves as a break in that smoothness:
- A dead patch — the tone almost disappears for part of the sweep and comes back. Often a blocked cavity or a partially detached driver.
- A buzz or rattle at particular frequencies — usually something loose in the cavity, or debris sitting on the diaphragm.
- A wet gurgle or a fluttering quality — liquid still moving in the chamber. Stop and run the water tone.
- Distortion that gets worse as it rises — sometimes just the volume; turn it down and repeat before concluding anything.
What the left and right test actually tells you
Most phones have one loudspeaker at the bottom and use the earpiece as a second channel for stereo. So a left/right test does not compare two identical speakers — it compares the loudspeaker with the earpiece.
That is exactly what makes it useful after water. If one channel is clear and the other is muffled, you have found which cavity holds the liquid, and you know whether a browser tone can reach it.
If both channels sound identical and centred, your browser may not support channel separation, or the phone is downmixing to mono. The tool will tell you if it cannot separate them.
Why this test stops at 1 kHz
A full-range speaker test would sweep to 20 kHz. This one does not, and the reason is the same one that governs every tool here: the site would then be handing you a loud high-frequency generator, which is the fastest way to damage hearing by accident.
For the job these tools are for — finding a blocked, wet or rattling phone speaker — the useful information is at the bottom of the range anyway. Obstructions and cavity problems show up in the low hundreds of hertz, not in the treble.
Before you conclude the speaker is broken
Rule out the boring explanations first, in this order:
- Volume limits and any hearing-safety setting the phone applies.
- A Bluetooth device that has quietly claimed the audio.
- A case or screen protector overlapping the grille.
- Headphone mode — the phone thinking something is plugged in.
- Dust, which is gradual, and water, which is sudden.
Only after all five is it reasonable to suspect the speaker itself.
Questions about testing a phone speaker
Why can't I test above 1 kHz?+
A cap at 1 kHz is a hearing-safety decision, matching the app. Loud high-frequency tones cause damage quickly and are easy to trigger by accident. Phone speaker obstructions are audible well below that ceiling.
The left and right buttons sound the same. Is that a fault?+
Usually not. Many phones downmix to mono at low volume or when only the loudspeaker is active, and some browsers do not support channel separation at all. It is only meaningful if one side is clearly worse than the other.
What volume should I use for the test?+
About half. High volume adds distortion of its own and will make a healthy speaker sound faulty, which defeats the purpose. Save maximum volume for the water tone, where the loudness is doing actual work.
The sweep buzzes at one pitch only. What does that mean?+
A single buzzing frequency usually means something is resonating loose — debris in the cavity, or a component vibrating against the housing. Run the dust cleaning tone; if the buzz survives that, it needs a physical look.