Getting computer audio into a podcast or stream is a routing problem: choose the application you want, send it into the recording or streaming mix, and verify that you are not capturing the same sound twice. The exact method depends on operating system, software, and interface. A cable that works on one setup may not be available or appropriate on another.
Start by listing the sources you need: microphone, browser or playback app, remote guest, and any alerts. Decide which should be heard by the audience and which should be sent to headphones. Then choose one route for each source. Duplicate routes are a common cause of echo or a delayed second copy.
Use software capture when the platform supports it
OBS has an Application Audio Capture source on supported Windows versions, which can capture selected apps instead of all desktop sound. The feature’s operating-system and OBS requirements can change, so check the current guide for your installed versions. Disable overlapping desktop capture if both sources would record the same app. On macOS, system-audio capture has different OS and OBS requirements; consult the OBS macOS audio guide for the version you run.
If you use an interface with loopback, its virtual channels can route computer playback into a recording or streaming input. The interface software determines how to assign those channels. Read the manufacturer’s current manual for your exact model; do not assume every interface provides loopback.
Check levels and monitoring
Play the source at its normal level and confirm the meter moves on the intended recording channel. Listen on headphones for clipping, delay, or a doubled signal. Keep system notification sounds out of the mix if they are not part of the show. Make a short test recording and play it back before going live.
If the audio is doubled, mute one path at a time until the duplicate disappears. If it is missing, follow the signal from the application to the capture source, then to the stream or recording bus. This is faster than randomly changing every device setting.
Draw the route before the session: playback app → capture input → recording/stream bus → headphones. If the meter moves but the audience hears nothing, check the output bus. If you hear a delayed duplicate, mute one capture path at a time; desktop audio and per-application capture can overlap. Test with the application you will actually use, since a route that works in OBS may not appear as an input in a separate recorder.
Write down the working input, output, and capture settings. Routing is reliable when each source has one clear path and the monitoring mix matches what the audience will hear.