Ultimate Guide to Fixing OBS Audio Sync Issues
Nothing ruins a stream faster than out-of-sync audio. If your webcam mouth movements don't match your voice, or your gunshot sound effect plays half a second after the visual muzzle flash, your production quality takes a nosedive. This mismatch is called Audio Desync or Latency.
Why Does Audio Desync Happen?
In the digital world, every device takes a tiny amount of time to process data. This processing time is called "latency."
- Microphones: Usually very fast (low latency).
- Webcams: Slower. They have to capture light, process the image, and send it over USB.
- Capture Cards: The slowest. Converting HDMI signals from a console to your PC takes significant time (often 30ms to 200ms).
Because your microphone is faster than your capture card, your voice arrives at OBS before your gameplay video. The result? You react to a jump scare before the viewers see it happen.
How to Measure Your Audio Delay
You can't fix it if you don't know the exact number. Here is the foolproof "Clap Test":
- Open OBS and start a Local Recording.
- Look at your camera and clap your hands loudly once.
- Stop recording and open the file in a video editor (like Premiere, Davinci Resolve, or even VLC frame-by-frame).
- Find the frame where your hands visually touch.
- Find the frame where the audio waveform spikes (the sound).
- Count the frames between the visual touch and the audio sound.
- Enter that number into our calculator above to get the exact millisecond offset.
Positive vs. Negative Offset
This is where everyone gets confused. In OBS Advanced Audio Properties:
- Positive Offset (e.g., 200ms): DELAYS the audio source. Use this if the audio is too fast (heard before seen). This is 99% of cases (delaying Mic to match Capture Card).
- Negative Offset (e.g., -200ms): ADVANCES the audio. This uses a buffer and is rarely needed unless your video is somehow faster than your audio (rare).
Common Sync Values
While every setup is unique, here are some typical offsets for popular hardware:
- Elgato HD60 S: ~650ms (on older PCs) or ~0ms (Instant Gameview)
- Generic USB 2.0 Capture Cards: ~50ms to ~150ms
- IP Cameras (NDI/RTMP): 200ms to 2000ms (High latency!)
- Bluetooth Headphones: Do not use for monitoring! They add 100-300ms of lag.