If an AAC file is silent in an OBS YouTube playlist, first find where the sound disappears: at source playback, in the local recording, or only in the YouTube output. OBS lists AAC as supported by Media Source, but the .aac extension alone cannot confirm that every file, container and playback path will work.
Check the OBS mixer meter while a single file plays, then make a short local recording. Those two tests narrow the cause before you change codecs, rebuild the playlist or alter stream settings.
Check where the audio disappears
Start with one file, not a long playlist. Let it play for long enough to pass any silent introduction, and note three separate observations: whether the OBS mixer meter moves, whether a local recording contains sound, and whether viewers can hear the YouTube output. These are different checkpoints; hearing audio on your own computer does not establish that it is reaching the stream.
A useful first pass looks like this:
| OBS meter | Local recording | YouTube output | First place to investigate |
|---|---|---|---|
| No movement | Silent | Silent | Source playback, selected file, or media compatibility |
| Moves | Silent | Silent | Recording track selection or OBS output configuration |
| Moves | Audible | Silent | Stream audio track and output routing |
| Moves | Audible | Audible | The basic path works; inspect playlist transitions or intermittent files |
This is a diagnostic guide, not a guarantee that every OBS version exposes identical controls. Make each test with the same source and file where possible. If you change the source and the audio settings at the same time, you may fix the symptom without learning which stage failed.
If the meter is still and a local recording is silent, leave YouTube settings alone for now. A stream route cannot carry audio OBS has not decoded into its mixer. If the local recording has sound but the YouTube output does not, the file has already passed a useful playback test; focus instead on which audio track the stream uses.
For a channel that plays a folder of videos, it can help to compare your source arrangement with a guide to making a YouTube live stream from a folder of videos. The aim here is narrower: identify whether this particular sound disappears before, during or after OBS mixing.
See whether the OBS source meter moves
Play the suspect file and watch the mixer for the corresponding source. If you cannot tell which meter belongs to the file, temporarily use a scene with only that audio source, or mute other audio sources one at a time. Avoid judging the meter by its colour alone: look for visible activity that follows the file's sound.
A moving meter means OBS is receiving audio at that point in the path. It does not prove that the audio is assigned to the stream track, included in the recording, or audible to viewers. A still meter points earlier in the chain: confirm the selected media, that playback has started, and that the source is active in the scene.
If you use OBS's Media Source, check that the intended local file is selected and that the source is not hidden or inactive under the behaviour you have configured. The OBS Media Sources documentation lists .aac among the audio types supported by Media Source and describes its playback controls. Support is a starting point for diagnosis, not a promise that every AAC bitstream or container combination will behave identically.
For playlist playback, establish which source actually owns the playlist. OBS's VLC Video Source is the playlist-capable source documented for use with VLC libraries; Media Source plays media files but is not the same playlist mechanism. If a source meter stays still, confirming the source type can prevent you from troubleshooting controls belonging to a different playback path.
Check a local recording for audio
Make a brief recording in OBS while the test file plays, then open that recording in a normal media player. Keep the test short and use a file you can recognise by sound. A local recording is more informative than listening to desktop monitoring alone because it tests what OBS wrote to a file, though it still does not prove that the live stream uses the same track.
Compare the recording with the mixer observation. If the meter moves but the recording is silent, inspect the recording's audio track selection and the source's track assignment. If both meter and recording contain sound, but YouTube does not, shift attention to the stream output track and routing. If the meter and recording are both silent, return to the source and media checks rather than changing YouTube settings at random.
Keep the evidence simple: source name, meter movement, recording result, and whether the live output has sound. If the problem began after an OBS or VLC update, note that too. These details help you reproduce the issue and distinguish a playback failure from a change in output configuration.
A user report on the OBS Project's GitHub issue tracker describes a case where VLC-source audio was heard locally and the meter responded, while live output was absent. Treat that as an example of why the checks should be separate, not as proof of a general defect or a diagnosis of your setup.
Verify the source and playlist playback path
For an OBS VLC Video Source playlist, check that VLC is installed. OBS's documentation says the source depends on VLC libraries and that 64-bit OBS requires 64-bit VLC. If the VLC Video Source option is missing or behaves differently from Media Source, confirm that the installed VLC architecture matches OBS before rebuilding the playlist.
Then test the same file outside the playlist in a simple scene. This helps separate a file-decoding problem from playlist handling. If it works as a single item but goes silent in the playlist, look at the playlist entry, repeat or transition behaviour, and whether the source is restarting or becoming inactive between items. Test a transition while watching the meter; silence only at a boundary suggests a different problem from silence throughout playback.
For a Media Source, verify the local-file setting, the selected path and playback state. OBS documents controls such as Loop and Restart playback when source becomes active. Those options affect how an item starts or repeats; they do not turn a single-file Media Source into the VLC playlist source. If you are building a continuous music channel, the separate guide to looping bhajans on YouTube Live with OBS may help you review the broader playback setup.
Check that the source is actually present and active in the scene being streamed. A scene change or visibility setting can affect a source when it is configured to restart or close while inactive. As a controlled test, keep the source visible and active, play one item, and watch its meter. If that works, test the intended scene transitions one at a time.
Inspect file and container interoperability
The file name is not a full description of the media inside it. AAC describes an audio codec, while a container describes how audio data is packaged. An .aac suffix does not, by itself, reveal every detail needed to explain why one player accepts the file and another does not.
If the file plays elsewhere but OBS has no meter activity, inspect the actual format and container with a media information tool you trust. Compare it with a file that does work in the same OBS source. The OBS Audio/Video Formats Guide describes AAC support across multiple container combinations; that breadth still leaves room for differences in a particular file or workflow.
If the evidence points to interoperability, make a copy and test a compatible container rather than overwriting the original. A remux changes the packaging without necessarily re-encoding the audio; conversion can change the audio encoding and may affect quality. Keep the source file and compare the copy in the same scene and playlist position. Do not treat one successful conversion as proof that all files with the same extension need conversion.
An OBS Project issue report about looping an AAC file includes a user report of success after remuxing to M4A or audio-only MP4. It is a report about one case, not a guaranteed remedy or a rule for all AAC files. Try that sort of test only after the meter and local recording suggest the failure is in playback or media compatibility.
YouTube's published audio requirements also need context. Its HLS setup guidance lists audio codecs and sample-rate requirements for HLS ingestion. Those instructions apply to that ingestion method; they are not a universal explanation for silence in a local OBS playlist or every way of streaming to YouTube.
Check OBS audio routing to the stream
When the meter moves and the local recording contains sound, check the path from the source to the stream. OBS can handle audio tracks separately, so verify that the source is assigned to the track you intend to send and that the stream output is configured to use that track. Labels and controls can vary by version and configuration, so confirm the actual selection rather than relying on a remembered setting.
If practical, make a short controlled live test with a sound you can identify, then check the YouTube output. Keep other audio sources muted during the test so you do not confuse desktop sound or another scene source with the playlist. A local recording with audio alongside a silent live output is a strong reason to inspect routing before changing the file.
Also distinguish local monitoring from stream output. Monitoring lets you hear audio on the computer; it is not the same test as whether the broadcast track receives that audio. If you change a track assignment or stream track, repeat the short local recording and the live test so you know which result changed.
For channels using OBS as part of a longer-running setup, the practical lesson from keeping a YouTube stream from going offline is to test the whole path under the conditions you plan to use. A playback meter is useful evidence, but a brief live check is the only direct check of the live output.
Test a known working file for comparison
Choose a file that you have already heard through this same OBS source, if one is available. Play it using the same scene, source type, track assignments and recording settings as the silent AAC item. Changing only the file makes the comparison useful; changing several settings at once makes it difficult to tell what mattered.
| Comparison result | What it suggests | Next check |
|---|---|---|
| Known file and AAC both silent | The problem may be in the source, scene or route | Confirm source activity and recording/stream track setup |
| Known file works; AAC is silent | The issue is more likely tied to that file or its handling | Inspect its container, playlist entry and playback state |
| AAC works alone but not in playlist | Playlist path or item transition deserves attention | Test another playlist item and watch the meter at transitions |
| Both work locally; only live output is silent | Playback is less likely to be the failure point | Verify the selected stream track and output configuration |
This table narrows the next test; it does not establish a cause on its own. Repeat the comparison after any change, and keep the original file so you can reverse a conversion or restore the prior playlist. If the problem remains intermittent, record which item was playing and whether the meter dropped at the same moment.
A short reproducible test is usually more valuable than leaving an overnight channel running to see whether it recovers. Once one file works in the intended source and reaches both a recording and a live test, add the remaining playlist items in manageable groups and check for a file-specific failure. For a broader view of the software choices involved in a long-running broadcast, see YouTube 24/7 live streaming software for Indian creators.
Decide what to change, and when
Use the evidence to choose the smallest change that addresses the failing stage. No meter activity calls for a source, playback or file check. Meter activity with a silent recording calls for recording-track and source assignment checks. Sound in a recording but not the live output calls for stream routing checks. A file that works alone but not as a playlist item calls for playlist and transition tests.
Change one thing at a time and keep a note of the result. For example, if you install matching VLC and the playlist source begins appearing, test one item before altering the container. If remuxing a copy makes its meter move, check the local recording and stream route as well; successful decoding is not the same as confirmed live output.
For an always-on channel, avoid treating a successful desktop preview as the final test. Check a recording, verify the intended live output, and then observe a playlist transition before relying on the setup. If you cannot reproduce the issue in a short test, gather the OBS and VLC versions, source type, file/container details and the three audio observations before seeking version-specific help.
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FAQ
Does OBS support AAC audio?
OBS lists .aac among the audio types supported by Media Source, and its format guide covers AAC in multiple container combinations. That does not mean every file or playlist workflow will behave the same way; check playback in your actual source and test the resulting recording.
Why does the OBS meter move if viewers hear nothing?
The meter shows activity inside OBS, not necessarily that the stream uses the same track. Check the source's track assignment and the audio track selected for the stream, then make a short live test. A local recording can help distinguish routing from playback, but it is a separate check.
Do I need VLC for an OBS playlist?
If you are using OBS's VLC Video Source, OBS documents it as playlist-capable and requiring VLC to be installed. Its documentation specifies matching 64-bit VLC for 64-bit OBS. Media Source is a different source with its own file-playback controls.
Should I convert every .aac file to M4A?
No. First establish whether the meter and local recording are silent, and compare the file with one that works in the same source. If the evidence points to a file/container interoperability issue, test a copy in a compatible container and keep the original; a reported success for one file is not a universal fix.