OBS Studio Media Source Audio Recording Issue - Need Help
System Configuration
Hardware: MacBook Pro with Apple M3 Max, 36 GB Memory
Operating System: macOS Version 15.5
OBS Studio Version: 31.1.1
Project Goal: Recording lyric commentary videos with separate audio tracks for voice commentary and video music
Problem Summary
I can successfully record microphone audio to Track 1, but cannot record Media Source audio to Track 2 without creating severe audio quality issues due to microphone pickup of system audio.
Current OBS Configuration
Audio Settings (OBS > Preferences > Audio)
- Sample Rate: 48 kHz
- Channels: Stereo
- Desktop Audio Device: Disabled (intentionally disabled to prevent system audio bleed)
- Desktop Audio Device 2: Disabled
- Mic/Auxiliary Audio Device: MacBook Pro Microphone
- All other mic inputs: Disabled
Recording Settings (OBS > Preferences > Output > Recording)
- Recording Format: Matroska Video (.mkv)
- Video Encoder: Apple VT H264 Hardware Encoder
- Audio Encoder: CoreAudio AAC
- Audio Tracks: 1 and 2 enabled (Track 1 for voice, Track 2 for video audio)
Sources Setup
- Media Source: MP4 video file with embedded audio
- Audio Input Capture: MacBook Pro Microphone
- Video Capture Device: FaceTime HD Camera
Advanced Audio Properties Configuration
- MacBook Microphone: Track 1 ✓, Track 2 ✗, Monitor: Off
- Media Source: Track 1 ✗, Track 2 ✓, Monitor: [This is where the problem occurs]
The Core Problem
Media Source Monitor Setting Dilemma:
When Media Source Monitor = "Monitor Off":
- ✅ No audio feedback or microphone pickup
- ❌ Video audio is NOT recorded to Track 2 (completely missing from final file)
- Result: Recording contains only microphone audio on Track 1
When Media Source Monitor = "Monitor and Output":
- ✅ Video audio IS recorded to Track 2
- ❌ Video audio plays through MacBook speakers
- ❌ Microphone picks up speaker audio, creating terrible quality audio bleed
- Result: Track 2 has good video audio, but Track 1 has voice + degraded video audio
Testing Results
Audio Isolation Verification
- Audio meters in OBS show Media Source audio activity during playback ✅
- Microphone meter only responds to voice input, not video audio ✅
- This confirms Desktop Audio: Disabled is working correctly
Recording Tests
- Monitor Off Test: Clean microphone recording, zero video audio in file
- Monitor and Output Test: Both tracks record, but microphone track has terrible audio bleed
- Different Media Files: Tested with MP4 and MP3 files - same behavior
- Hardware Decoding: Tried disabling "Use hardware decoding when available" - no change
What I've Tried
Configuration Attempts
- Verified all audio track assignments multiple times
- Tested different media source settings (hardware decoding, loop options)
- Confirmed recording format and encoder settings
- Tested with different video file formats (.mp4, .mp3)
Hardware Variables
- MacBook Pro built-in microphone and speakers only
- No external audio interface available
- Bluetooth devices disconnected during testing
- System volume adjustments (minimal impact)
Expected Workflow
The intended recording process:
- Start recording with live camera and microphone (Track 1)
- Play lyric videos with music (Track 2)
- Pause videos for live commentary
- Resume videos after commentary
- Switch between different videos for comparison
- Final output: Clean separated tracks for post-production
Questions for the Community
- Is there a way to force Media Source audio recording without requiring "Monitor and Output"?
- Are there alternative source types (VLC Video Source, etc.) that handle audio routing differently?
- Could this be a macOS-specific limitation with CoreAudio and OBS integration?
- Is there an OBS plugin or alternative approach for media playback with isolated audio recording?
- Would an external audio interface solve this routing issue, or is this a fundamental OBS limitation?
Additional Context
Why Desktop Audio is Disabled
I intentionally disabled Desktop Audio in OBS because it was causing the exact microphone pickup problem I'm trying to avoid. With Desktop Audio enabled, all system audio gets captured by the microphone input, creating the same audio quality issues.
Hardware Constraints
- Limited to MacBook Pro built-in audio hardware
- No wired headphones available (only Bluetooth, which causes additional audio routing conflicts)
- Budget constraints for external audio interfaces
Alternative Software Consideration
I previously attempted this workflow in Ecamm Live but encountered different limitations (resizable video overlays don't support audio playback). OBS provides the necessary video control but has this audio routing challenge.
Ideal Solution
A configuration that allows:
- Media Source audio recording to Track 2 without speaker output
- Microphone recording to Track 1 without system audio pickup
- Real-time video playback control (play/pause/resume)
- No audio quality degradation or bleed between tracks
Thank You
Any insights, alternative approaches, or solutions would be greatly appreciated. This seems like it should be a common use case for content creators, so I'm hoping there's a solution I'm missing.
System Details for Reference:
- OBS 31.1.1 on macOS 15.5
- Apple M3 Max MacBook Pro
- Recording to MKV with multi-track audio
- Goal: Lyric commentary videos with separated audio tracks