How do I send room audio to SyncWords using OBS?
Learn how to configure OBS Studio to send live room audio to your SyncWords Service.
If you need to send room audio from a laptop or PC to SyncWords, OBS is a straightforward option. It is free, widely used in professional AV settings, and supports RTMP streaming.
Prerequisites
Before you begin, ensure you have:
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OBS Studio installed on the laptop or PC that will send the audio
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A SyncWords Service configured
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Your Stream URL and Stream Key from your SyncWords Service
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Room audio routed into your computer (see Step 1 below)
Step 1 - Get the Room Audio into Your Computer
You need an audio source connected to the computer running OBS.
Preferred: Take a line-level output from the room mixer via a USB audio interface. This provides a clean, direct feed with no room noise.
Alternative: A USB microphone or the AV system's audio output fed into the computer can work, but audio quality may be lower.
IMPORTANT: Avoid using the laptop's built-in microphone. It will pick up room noise and significantly reduce captioning accuracy.
Step 2 - Add the Audio Source in OBS
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In the Sources panel, click + and choose Audio Input Capture
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Select your USB audio interface or mixer output as the device
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Confirm the level meter is active in the Audio Mixer panel
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Mute any unnecessary sources, such as the laptop's built-in microphone
TIP: If the level meter is not moving, verify that your audio interface is selected as the correct device and that the mixer is sending signal to that output.
Step 3 - Configure the Streaming Endpoint
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Go to Settings, then Stream
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Set Service to Custom
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Server: Enter the Stream URL provided by your SyncWords Service
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Stream Key: Enter the Stream Key provided by your SyncWords Service
NOTE: Your Stream URL and Stream Key are found on the Service Overview page in SyncWords after the Service has been created.
Step 4 - Configure the Audio Output Settings
Go to Settings, then Output, then the Streaming tab.
| Setting | Recommended Value |
| Audio encoder | AAC |
| Bitrate | 128 kbps |
| Sample rate | 48 kHz |
| Channels | Mono |
NOTE: For captioning purposes, audio clarity and a clean, low-latency direct feed are more important than high bitrate. Mono is recommended for speech recognition, and 128 kbps is adequate for captioning.
Step 5 - Start the Stream
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Start your SyncWords Service from the Services page
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Click Start Streaming in OBS
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OBS will begin sending the audio feed to the SyncWords RTMP endpoint continuously
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Check the SyncWords interface to confirm the incoming audio is being received and captions are being generated
TIPS:
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Run a 5 to 10 minute test before your event to verify audio levels, connectivity, and that SyncWords is receiving the stream correctly.
- If the stream from OBS disconnects and does not automatically reconnect, or you see a connection failed error, restart your Service in SyncWords and then reconnect from OBS.