🔧 Troubleshooting

Fixing Audio Sync Issues in Video Capture

Identify the Source of the Problem

Determine whether audio and video are out of sync in the captured file/stream, or only in the live monitor preview. Preview latency is normal. If the finished recording or stream is out of sync, the problem is in the capture or encoding pipeline.

OBS Audio Sync Offset

In OBS, open the Audio Mixer panel. Next to each audio source, click the gear icon and select Advanced Audio Properties. You will see a Sync Offset field. Enter a positive value (in milliseconds) to delay the audio. Start with +50ms and adjust.

Common Causes

HDMI audio arriving before video: Video processing takes slightly longer than audio extraction. Add a 50-100ms audio delay in the OBS sync offset field.

Bluetooth headset audio: Bluetooth audio has inherent latency (typically 100-300ms). The recording itself may be fine — it is your monitoring that sounds delayed.

Software encoder latency: Try a hardware encoder (NVENC, AMF, QuickSync) which has lower processing latency than x264.

Testing Your Setup

Clap your hands in front of the camera. Review the recording. The clap should be visible and audible at the same frame. If video leads audio, add audio delay via the sync offset. If audio leads video, add video delay via the Video Delay filter on the capture source in OBS.

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Troubleshooting

Frequently Asked Questions

Audio sync issues are usually caused by processing delay in the capture pipeline. In OBS, adjust the Audio Sync Offset on the capture source. In vMix and other software there are similar per-source delay controls. Start at 0ms and increase in 20ms steps until audio and video align.

Right-click your Magewell source in OBS, select Properties, and find the Audio Sync Offset field. Increase this value (typically 50–200ms) until audio matches video. The exact value depends on your source device and system.

Yes. All Magewell HDMI capture products capture HDMI embedded audio alongside video. The audio appears as a separate audio source in your capture software. SDI products capture embedded SDI audio.

Audio sync issues are almost always caused by the downstream software rather than the capture device. Common causes include mismatched sample rates (set audio to 48kHz), buffering settings in OBS, or software encoding introducing variable latency. Magewell capture devices deliver audio and video with hardware-synchronised timestamps.

In OBS, add a fixed Audio Offset under the audio source properties — try 0ms first and adjust in 10ms increments. Switch to hardware encoding (NVENC/QuickSync) to reduce variable latency. Ensure your audio sample rate matches in both the capture source and OBS audio settings (48kHz recommended).

Yes. All Magewell HDMI and SDI capture devices capture embedded audio alongside video. HDMI captures up to 8 channels; SDI up to 16 channels. The audio channels are individually accessible in compatible software such as vMix, OBS, and Magewell Capture Express.

Check that the source device is outputting embedded audio on the HDMI or SDI signal. Use the Magewell Capture Utility to verify the device is detecting an audio signal. In OBS, ensure the Magewell device is set as the audio source. If using a gaming console, check the console audio output is set to HDMI rather than optical or headphone output.