Speaker test: left, right, distortion

When to test the speakers

Test the speakers when you look at a used device, after a screen or battery replacement (the earpiece and loudspeaker often have to come out), and if the device has been in water. Unplug any headphones and disconnect Bluetooth speakers or earbuds first, so the sound comes from the device's own speakers.

Common faults and their causes

• Crackling or distortion at high volume: a torn or warped speaker membrane, often after water damage or long use at full volume.
• Quiet or muffled sound: dust or grime blocking the speaker grille. Try cleaning it gently with a dry, soft brush before drawing conclusions.
• Rattling at one frequency: a loose screw or part inside, or a bent frame.
• One speaker silent: many phones use the earpiece at the top as the second speaker. If it fails you still hear the bottom speaker, but you lose stereo.

What to do if you find a fault

• Clean the grille, turn off sound effects (Dolby Atmos, equaliser) and test again.
• Make a phone call to hear the earpiece: a web page can't target that speaker on every device.
• Then test the microphone. If the device was just repaired, see checking a device after a repair.