Blocked or broken: telling what is actually wrong with your speaker

One of these you can fix in two minutes at your kitchen table. The other needs a repair shop and costs money. They produce different sounds, and once you know which sound is which you will never confuse them again.

Sound

Speaker faults sort into two piles. In the first, the speaker is working perfectly and something is in the way — water, lint, sand, a case. In the second, the driver, its connector or the audio circuit behind it has actually failed. Everything you might usefully do depends on which pile you are in, and the fastest way to find out is to listen to the character of the sound rather than its volume.

The two-minute triage

Run through these in order. You can stop at the first one that gives you an answer.

  1. Turn Bluetooth off entirely. Not “check the icon” — off. A phone playing into earbuds in a bag is the single most common “dead speaker” on the internet.
  2. Take the case off and turn media volume all the way up, with any hearing-safety cap disabled.
  3. Restart the phone. Audio routing gets stuck occasionally, and this costs thirty seconds.
  4. Play through each speaker separately — how to do it here. You are comparing the top and bottom against each other, not judging either alone.
  5. Listen to the character, not the level: quiet-and-dull, or crackling-and-buzzing? That is the fork in the road, and the table below is what it means.
  6. Run one cleaning cycle and repeat the comparison. Something that improves was blocked. Something identical was not.

What each symptom means

SymptomAlmost alwaysDo this
Quiet and dull, no trebleBlocked — water or lintCleaning cycle, then a soft brush
Muffled since it got wetWater in the cavityEject the water
Crackling, buzzing, rattlingDamaged or corroded driverRepair. Cleaning cannot help
Cuts in and outLoose connector or corrosionRepair
Silent on one speaker onlyTotal blockage, or a dead driverClean twice; if nothing, repair
Silent on both, suddenlySoftware, or the audio circuitRestart, then update, then repair
Fine on speaker, dead on callsThe earpiece, or the proximity sensorClean the earpiece slot first
Distorts only at maximumUsually normalNothing. Small drivers do this

Why crackling is the important one

A blockage subtracts. It takes away volume and takes away the top end, and what is left is a quieter, duller version of the right sound. Nothing is added.

Crackling, buzzing and rattling are additions — sounds that were not in the signal. Something is physically touching something it should not: a torn or deformed membrane, a loose particle sitting on the driver, or corrosion on a contact producing an intermittent connection. No amount of cleaning tone removes any of those, and running a full-volume low-frequency cycle through a driver that is already flapping against something is actively a bad idea.

The corrosion timeline

There is a particular pattern worth recognising because it confuses a lot of people. A phone gets wet — often in the sea or a pool. It is dried, it works, the speaker even sounds fine. A few days or a couple of weeks later the speaker starts crackling, or goes quiet, or dies.

That is not a new fault, it is the old one arriving. Salt water and chlorinated water leave a conductive, corrosive residue when they evaporate, and that residue keeps working on contacts long after the phone is dry. It is the reason the first thirty minutes tells you to rinse a sea-water phone with fresh water — you are removing the salt, not the water.

If this is your pattern, cleaning tones are not the answer and never were. Go to a shop, and mention the water — a technician who knows to look for corrosion finds it far faster.

Things that are not the speaker at all

The other person cannot hear you
That is a microphone, which is a completely different component that happens to sit behind an identical-looking grille on the bottom edge. Record a voice memo and play it back — if the recording is fine, the microphone is fine.
Calls are silent but music is fine
Calls default to the earpiece. Try the loudspeaker button mid-call: if that works, the earpiece slot is blocked or failing and the main speaker is untouched.
The screen goes dark and audio dies on calls
The proximity sensor, which sits in the same slot as the earpiece and gets blocked by the same lint. Cleaning the slot often fixes both at once.
One app is quiet, everything else is fine
Per-app volume, an in-app setting, or a stuck audio session. Not a hardware problem; force-quit the app.
It went quiet after an update
Check the accessibility and hearing-safety settings, which occasionally reset. Then restart. A hardware fault does not usually coincide with an update.

When to stop and pay someone

A reasonable stopping rule: if two cleaning cycles and a careful brush of the grille have produced no measurable change in a direct before-and-after comparison, further cycles will not either. The failure mode here is not doing too little, it is spending a fortnight running cycles on a speaker that has a corroded contact.

Take it in if any of these are true: it crackles or buzzes; it cuts in and out; one speaker is silent after cleaning; it got wet and then degraded days later; or it is dead on both speakers with no software explanation. A speaker replacement is one of the cheaper phone repairs, and a technician can tell corrosion from a blockage in about a minute with the back off.

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