Why are my speakers crackling or popping?
Crackle has several distinct causes and each one sounds slightly different. Identifying which you have narrows the fix considerably.
Crackle is a family of problems rather than one, and they sound subtly different. Working out which you have removes most of the guesswork.
Identify the pattern
Constant crackle regardless of what is playing points at the connection: a cable, a plug or a socket making intermittent contact.
Crackle only at high volume is the amplifier clipping or the driver reaching its limit. This is a physical ceiling rather than a fault, particularly on small speakers.
Crackle at specific frequencies only is resonance. Something is vibrating in sympathy, and it is usually not the speaker.
Crackle in bursts, unrelated to volume is usually software: buffer underruns, a sample rate mismatch, or an audio enhancement effect.
Crackle on one side only narrows it immediately to that channel’s cable, plug or driver, since everything shared is working.
Connection problems
Analogue plugs fail more often than speakers do, and they fail at the point of most flex.
Play a steady tone and gently wiggle the plug where it enters the socket. If the crackle tracks the movement, the plug or the socket is the fault. Do the same at the far end and at any point where the cable bends sharply.
A plug that is not fully inserted causes this too, so push it home firmly first. Remove any adapter that is holding it slightly out.
Resonance
This one surprises people, because the speaker sounds broken and nothing is wrong with it.
Sweep the frequency range and note where the buzz appears. If it occupies a narrow band and is clean either side, something is resonating at that frequency. Candidates are a loose laptop panel, a desk with something sitting on it, a speaker grille that has come slightly loose, or an object nearby.
Move the speaker to a different surface, hold it in your hand, and sweep again. If the buzz disappears, the speaker is fine and the furniture was the problem.
Software causes
Audio enhancements. Bass boost, virtual surround and loudness equalisation all manipulate the signal and can push it into clipping. Turning them all off is a fast test.
Sample rate mismatch. If your output device is set to a rate that does not match what is playing, some systems resample badly and produce intermittent artefacts. Setting the device to 44.1 or 48 kHz resolves most of it.
Buffer underruns. Crackle that arrives in bursts when the system is busy is the audio buffer running dry. Closing heavy applications, and checking for a process using sustained CPU, usually confirms it.
Exclusive mode conflicts. An application taking exclusive control of the audio device while another tries to use it can produce popping at the moment of the switch.
Bluetooth specifically
Wireless adds its own failure mode. Interference from other 2.4GHz devices, distance, and a body between the transmitter and receiver all cause dropouts that sound like crackle.
Test wired through the same speakers. If wired is clean, the problem is the link rather than the hardware at either end.
When it is the driver
If the crackle follows the speaker when you swap sides, happens at all volumes, happens with multiple sources, and persists wired, the driver itself is likely damaged.
A driver that has been overdriven can have a torn surround or a rubbing voice coil, and both produce a distinctive rasp on low frequencies in particular. That is a repair or a replacement rather than a setting.
Common questions
Why does it only crackle at high volume?
Either the amplifier is being driven past its limit, which is clipping, or the driver is reaching the end of its physical travel. Both are more common on small speakers. If it is clean until a certain point and then breaks up, that is the limit of the hardware rather than a fault.
It crackles only at certain frequencies.
That points at resonance rather than electronics. Something is vibrating at that frequency: a loose panel, an object on the same surface, or the speaker housing itself. Move the speaker to a different surface and sweep again to confirm.
The crackling started after a driver update.
Then it is very likely software. Audio enhancement features and sample rate mismatches both produce crackle, and updates reset those settings. Turn off any audio enhancements and set the sample rate back to 44.1 or 48 kHz.
Both Bluetooth and wired crackle.
That rules out the wireless link and points at either the speakers themselves or something shared upstream, such as the audio driver or a system-wide effect. If a different device also crackles through the same speakers, the speakers are the fault.