Record video and broadcast radio at the same time in OBS

The problem most users hit

OBS Studio's main output, by default, sends one thing somewhere. You can record video to disk, or you can stream it to Twitch, or you can stream it to YouTube. The "Start Streaming" button hands the encoded output to one destination. Switching destinations stops one to start the other.

For most workflows, that is fine. But there are real situations where you want more than one output happening simultaneously:

• A talk show producer streams the video portion to YouTube while broadcasting just the audio to an Icecast or AzuraCast station for radio listeners.
• A musician records a performance to disk in pristine quality and broadcasts a compressed audio mix to a live Icecast mount for fans listening on phones.
• A gaming streamer pushes video to Twitch and a separate stripped-down audio feed to a community Icecast server.
• A podcaster records the multi-track session locally for editing and pushes the live mix to a station feed in real time.

OBS handles two of those with built-in features (recording plus streaming work in parallel). It does not handle the radio audio piece without additional tooling.

The architecture

OBS internally has three relevant outputs:

• Streaming output: the main encoder that pushes video plus audio to a single destination (Twitch, YouTube, RTMP, custom).
• Recording output: writes video plus audio to a local file. Already independent of streaming.
• Plugins. OBS plugins can register their own outputs that read from the same audio and video sources without competing for the main encoder.

Radio Streamer registers as a third output that reads from one OBS audio track, encodes via FFmpeg, and pushes to an Icecast mount. It does not touch the streaming or recording outputs. All three run in parallel.

This architecture is the reason the plugin exists. Hijacking the recording or streaming output to push to Icecast (a pattern some old guides recommend) ties up the main encoder. Radio Streamer leaves both free.

Step-by-step setup

1. Install Radio Streamer. Follow the install steps if it is not already in your OBS.
2. Decide your audio strategy. Most of the time you want different audio mixes for the video output and the radio output. If you want them identical, route every source to both Track 1 and Track 2.
3. Configure tracks. Open OBS, then Audio Mixer > gear icon on a source > Advanced Audio Properties. For each source, check the tracks it should appear on. Track 1 is conventional for video stream; Track 2 for radio.
4. Set your video stream output to use Track 1. Open Settings > Output > Streaming. Under "Audio Track", pick Track 1.
5. Set your recording to whatever tracks you want preserved. Recording can include multiple tracks if you choose Settings > Output > Recording with type "MKV" or "fMP4".
6. Configure Radio Streamer. Open Docks > Radio Streamer. Set the Icecast URL, codec, bitrate, and pick Track 2 in the audio track selector.
7. Start everything. In any order. Each output is independent.

Audio routing strategy

The OBS audio mixer assigns each source to one or more tracks. For a parallel video-and-radio setup, the routing usually looks like this:

• Mic: Track 1 + Track 2 (you want voice in both the video stream and the radio).
• Music player: Track 1 + Track 2 (same).
• Game audio (if you have it): Track 1 only (irrelevant or distracting on radio).
• Caller audio (if you have it): Track 1 + Track 2.
• Soundboard / sound effects: Track 1 only, unless they are part of the radio show.

The principle: the video stream usually wants everything, the radio wants just the show. Stripping non-essential audio from Track 2 keeps the radio mix clean.

Verifying both pipelines run independently

Three quick checks confirm the outputs really are independent:

1. Start the radio broadcast first. Do not start the video stream. Confirm Icecast shows a live source on the mount.
2. Start the video stream while the radio is live. The radio mount should not flicker or drop. Twitch or YouTube should come up normally.
3. Stop the video stream. The radio mount stays connected. Listeners do not hear a gap.

If any of these steps interrupts the radio mount, something is wrong with the setup, usually because OBS is configured to use the same audio device for both pipelines and the device gets seized when one starts. The Track 2 separation should prevent this.

Workflow examples

Twitch streamer with a community radio side channel

Track 1 carries everything (mic, game audio, music). Track 2 carries mic and music only. OBS streams Track 1 to Twitch as part of the main video output. Radio Streamer pushes Track 2 to icecast://source:pass@radio.example.com:8000/community.mp3. Game audio stays out of the radio mount.

Podcast video plus radio simulcast

Two hosts on camera, video recorded locally with Track 1 (full mix). Track 2 carries just host mics. OBS records the video to MKV. Radio Streamer pushes Track 2 to AzuraCast. The recorded MKV becomes the YouTube upload later; the live Icecast mount goes out in real time.

Music performance with parallel high-quality recording

Track 1 has the full performance mix from a connected mixing board. Track 2 has the same mix but already downmixed to stereo. OBS records Track 1 in lossless WAV via the recording output. Radio Streamer pushes Track 2 as Opus at 96 kbps for the live audience. The recording becomes the album later; the broadcast goes out now.

Common mistakes

Same source on the wrong track

The most frequent issue is forgetting to route the radio-relevant sources to Track 2. The Icecast mount connects, but listeners hear silence because Track 2 has nothing on it. Open Advanced Audio Properties and confirm at least one source has Track 2 checked.

Track monitoring confusion

OBS's "Audio Monitoring" controls which audio you hear in your headphones, not what gets sent to outputs. Setting a source to "Monitor Only" means it is not in any track. For radio, set to "Monitor and Output" if you also want to hear it locally.

Trying to stream from the recording output

Some old guides recommend pointing OBS's recording output at an FFmpeg pipe configured for Icecast. That works in a narrow sense but ties up the recording pipeline; you cannot also record locally. Radio Streamer exists to avoid this tradeoff.

Wrap up

Once routing is set up, running three pipelines in parallel feels normal. Recording stays local, the video stream goes to one destination, and the radio mount goes to Icecast or AzuraCast. The encoder pipelines are isolated, so starting or stopping one never disturbs the others.