Speakers Crackling or Popping
Crackling has two very different families of causes: electrical (cables, connectors, ground loops) and digital (a computer that cannot deliver audio on time). Test with steady tones on the audio test so you can hear when the crackle happens.
Does it crackle on every source?
Play from a phone to the same speakers. If the crackle disappears, the computer is the cause; if it stays, look at the speakers, cables and power.
Ground loop hum and buzz
A steady 50/60 Hz hum, often louder with a laptop charger plugged in, is a ground loop. Plug everything into the same power strip, or use a ground loop isolator on the audio line.
Bluetooth crackle
Move closer, avoid USB 3 ports and Wi-Fi routers near the receiver, and turn off other Bluetooth devices.
Cables and connectors
Wiggle each cable and connector while playing pink noise. Replace any cable that makes the crackle come and go. Clean oxidised RCA or 3.5 mm plugs by plugging them in and out a few times.
Damaged drivers
If crackling appears only at higher volume or on bass, the cone or voice coil may rub. Use the frequency sweep at low volume: a rattle at a particular frequency points to a mechanical fault.
Computer causes (Windows)
Change the default format (Sound → Properties → Advanced), turn off enhancements, update chipset and audio drivers, and disable power saving for USB audio. Tools that measure DPC latency can identify drivers that delay audio.
Related tools
Frequently Asked Questions
Q.Is crackling bad for speakers?
Electrical pops at high volume can damage tweeters; fix it soon.
Q.Why does it crackle only when the PC is busy?
The computer misses audio deadlines; it is a driver or power-setting issue.