How to Fix Audio Crackling

Three timing patterns isolate the cause. (A) Crackling during recording or playback in the DAW, scaling with project complexity (more tracks, more plugins = more crackle): buffer underrun. (B) Crackling on every playback of a specific file regardless of player: defect baked into the file from a recording-chain problem or file corruption. (C) Crackling during playback on one specific device or output (Bluetooth speaker, particular USB port, certain Bluetooth headphones) but not others: device-specific issue, not a file or DAW issue. Run the diagnostic: load the suspect file in three players (DAW, VLC, browser audio) and play through three outputs (built-in speakers, wired headphones, Bluetooth). The combination that crackles points to whichever component is shared.

By far the most common cause of session-time crackling. The audio buffer holds samples between CPU processing and the audio interface. If the CPU cannot fill the buffer fast enough — too many plugins, slow CPU, system tasks competing for cycles — the buffer empties and the interface plays silence for one cycle, creating a pop or crackle. Fix: raise the buffer size in your DAW's audio preferences. Typical values: 64, 128, 256, 512, 1024 samples. Start at 512 samples for tracking sessions, 1024 for mixing — latency rises but stability improves dramatically. Disable competing tasks: close browser tabs playing video, kill Spotify and Discord, pause Time Machine and Spotlight indexing. On laptops, plug into mains power; battery saver throttles CPU. Freeze plugin-heavy tracks. See [fix-audio-clicks-pops](/guide/fix-audio-clicks-pops) for the related transient pop topic.

On Windows, the driver model matters enormously. WDM and WASAPI shared-mode drivers (system defaults) cause occasional crackling under load and high latency. Use ASIO drivers from your audio interface manufacturer (Focusrite, RME, MOTU, PreSonus all ship dedicated ASIO drivers); ASIO bypasses Windows audio mixing for direct buffer-to-hardware delivery. WASAPI exclusive mode is acceptable for stereo playback but not for multitrack recording. On macOS, Core Audio is solid but check Audio MIDI Setup for conflicting aggregate devices and ensure your interface is selected as both input and output in the DAW. Update interface drivers — outdated firmware is a recurring source of crackle that disappears with the manufacturer's latest driver. Linux: ALSA and JACK; raise JACK buffer size and process priority for stable low-latency.

USB-bus-powered audio interfaces share power and bandwidth with everything else on the USB controller. Symptoms: crackling that appears when you plug in another USB device, that varies with computer load, or that goes away when you unplug other peripherals. Fixes: plug the interface into a USB port directly on the computer, not via a hub or dock. On laptops, USB-A and USB-C ports often run on separate controllers — try the other type. Use a powered USB hub with a high-quality linear power supply if a hub is unavoidable. On Windows: disable USB selective suspend in Power Options > Advanced > USB settings; this prevents the OS from cutting USB power during quiet moments. On Macs: avoid sharing the USB bus with external SSDs and phones charging. For interfaces with their own DC supply, use it; bus-powered convenience is not worth chronic crackling.

If the crackling is in the file itself — present in every player, on every device — it was recorded that way and will not go away with playback tweaks. Inspect the file in Audacity (convert lossy sources to [WAV](/convert/mp3-to-wav) first, lossy compression hides single-sample defects). Patterns: regular, periodic crackle = sample-rate mismatch during recording; rare, isolated pops = buffer underruns during the original recording session; continuous low-level crackle = electrical interference (ground loop, USB power noise, RFI from a mobile phone near a mic cable) or a damaged cable; sudden bursts = hardware fault or file corruption. Fixes for the recording side: see [fix-audio-hum](/guide/fix-audio-hum) and [fix-audio-clicks-pops](/guide/fix-audio-clicks-pops). Repair the file with iZotope RX De-click; expect partial restoration only.

Corrupted MP3 or AAC frames produce specific glitch patterns: a brief click followed by static lasting a fraction of a second. Causes: incomplete download, interrupted disk write, defective storage media, or encoder bugs. Diagnose: try the file in VLC (very tolerant of corruption) and in iTunes/Music (strict). If VLC plays cleanly while iTunes glitches, frame-level corruption is present. Repair: convert to [WAV](/convert/mp3-to-wav) — the decoder skips corrupt frames and writes silence at those points, which sounds worse than the crackle but at least decodes deterministically. Re-download or re-rip from the original source if possible. Pure codec artefact crackle (encoded too low bitrate) cannot be repaired — re-encode from a higher-quality source. MP3 below 96 kbps and AAC below 64 kbps both produce audible 'birdies' and crackle on cymbals and sibilants.

Crackle that appears only on one playback device is a device problem, not a file problem. Bluetooth speakers and headphones: interference from Wi-Fi, other Bluetooth devices, or distance > 5 m drops packets and inserts crackle on decode. Move closer to the source, disable nearby Bluetooth devices, ensure speaker firmware is current. Car AUX inputs: dirty 3.5 mm jack causing intermittent contact — clean with isopropyl alcohol on a cotton swab; replace the cable. Built-in laptop or phone speakers: physical damage to the cone or voice coil, especially after exposure to moisture; usually unrepairable, route audio to external speakers or replace. Smart speakers (Echo, Sonos, Google Home): streaming buffer issues caused by Wi-Fi congestion; move the speaker closer to the router or switch to 5 GHz Wi-Fi. None of these are fixed by re-converting the file.

Crackling pattern → likely cause → fix. Periodic clicks during DAW playback → buffer underrun → raise buffer to 512+ samples. Random crackle that scales with system load → driver/USB → switch to ASIO or move USB port. Continuous low-level hiss-and-crackle on a recording → ground loop / RFI → see [fix-audio-hum](/guide/fix-audio-hum). Crackle on cymbals or sibilants in MP3 → low-bitrate codec artefact → re-encode from higher-quality source. Crackle in one specific file across all players → corruption or recorded defect → convert to [WAV](/convert/mp3-to-wav) and inspect waveform. Crackle on Bluetooth only → interference → move closer, update firmware. Crackle on car AUX only → dirty jack → clean and try new cable. When in doubt: convert to WAV, inspect waveform in Audacity, locate the visual artefact, and trace which step in the chain introduced it. See [fix-audio-distortion](/guide/fix-audio-distortion) for the broader distortion topic.