If your YouTube Live loop shows video but has no sound, trace the audio from the MP4 through OBS and into YouTube rather than changing settings at random. First confirm the file contains audible audio, then check the active OBS source and mixer before using YouTube’s preview to verify what viewers receive.
This checklist is written for the common setup where an OBS Media Source plays a prerecorded MP4, but a silent file, a different scene, encoder output, or audio routing can also be responsible. Follow the signal in order: stop at the first point where expected sound disappears, correct that point, then test the whole route again.
1. Confirm the MP4 contains an audio track
Start outside OBS. Open the exact MP4 that the live scene is meant to play in a media player and listen to a section you know should contain sound. Do not rely only on the thumbnail, filename, or the fact that the picture plays. A video file can contain no audio stream, or it can have an audio track that is silent during the section you happened to check.
If the player is silent, inspect the file’s audio track information with a media tool you already trust, or try another known-good player. Confirm that an audio stream exists and that it is the expected soundtrack, such as the bhajan, narration, ambience, or lesson audio you intended to include. If it is absent or silent, OBS cannot send sound that is not in the source. Choose a corrected file or add a separate audio source deliberately.
Keep the test focused on the precise file selected for the broadcast. A common mix-up is checking an edited master but leaving an older export selected in OBS. Compare the file name and location in the player with the one shown by the OBS source’s properties. For a phone recording, make sure the export has finished and that the copy used for streaming is not a muted draft.
OBS supports MP4 as a Media Source format, and its Loop property restarts playback at the end of the file; neither fact confirms that the MP4 contains sound. The OBS Media Sources guide explains the source and its looping behaviour. If you are preparing recordings from a phone, the guide to removing variable frame rate before using OBS is relevant to video playback stability, though frame rate work does not add a missing audio track.
If the file plays correctly in another player, move to OBS without re-encoding it as a first resort. Conversion can be useful when an actual compatibility problem is indicated, but it will not repair an absent soundtrack by itself. Locate where the audio first vanishes before making a new export.
2. Play the source in the active OBS scene
In OBS, open the scene that is actually being sent to YouTube. Select the Media Source and check its properties: confirm it points to the intended local MP4, and that playback is active. The scene preview should show the expected video at the point you are testing. If the source is hidden, stopped, or covered by a different scene, its audio may not be the audio reaching the live programme either.
Use a known audible passage rather than judging from the opening frame. If the MP4 begins with a silent title card, wait until speech or music should start. For a loop, you may also test near the end and across the restart, since a playback or scene transition issue can be distinct from a file that is silent throughout. Looping tells OBS to start the file again after it ends; it does not test the sound path.
If you have multiple Media Sources, temporarily identify the source you expect to hear and make sure it is the one present in the live scene. A duplicate source can point to an older file or be paused while another copy supplies the picture. Avoid deleting and rebuilding the scene until you know what is wrong; first check source selection, visibility, playback state, and the file path.
A Media Source may be configured to close when inactive, so a scene change can affect whether it resumes as expected. Test while the intended scene is selected and active, and note whether the audio disappears only after switching scenes. The OBS Media Sources documentation is the primary reference for its available properties. For a more involved prerecorded setup, the walkthrough on looping a folder of MP4 files in a YouTube Live stream can help distinguish a single-file source check from playlist behaviour.
3. Watch the source audio meter
With the clip playing through an audible passage, look at OBS’s Audio Mixer. Find the entry for the Media Source and watch its meter. A moving meter indicates that OBS is receiving a level from that source at the mixer; a meter that stays still when the file is known to be audible gives you a useful boundary for the diagnosis.
If the meter does not move, return to the file and source checks. Confirm you are looking at the right mixer entry, the source is playing, and the audible part of the clip has begun. If those are correct, investigate how OBS is opening or decoding that media rather than assuming YouTube is the problem. A different MP4 can serve as a controlled test: if it produces a meter reading in the same scene, compare its source and audio stream with the original.
If the meter moves, OBS is seeing source audio at that point, but this alone does not establish that the audience hears it. Continue through mute, fader, scene and encoder checks. The goal is to locate the first point where the signal stops, not to treat a moving meter as proof that the complete path works.
OBS’s Audio Mixer Guide describes the mixer meter and its controls. It is a useful distinction when you are working from a small studio, temple office, shop or home: you can use the on-screen meter as a signal check even if you are not yet listening through headphones. Do not raise every slider simply because one meter looks low; first check whether it moves at all and whether it is the intended source.
4. Check mute, fader and scene state
For the Media Source’s mixer row, check the mute control and fader position while the clip plays. A muted source will not contribute its sound to the mix, while a fader pulled down can make its level effectively inaudible. If you make a change, do it in a controlled way and watch the meter and test output again. Take care not to alter other sources, such as a microphone or desktop audio, unless they are part of the same diagnosis.
Then confirm the scene itself is live. OBS can show one scene in its preview while another scene remains on air, depending on your Studio Mode and transition state. Check the programme output or the scene selected for the broadcast, not only the editing preview. If the MP4 source is in a scene that is not currently live, its meter can be active while viewers see a different output.
Local monitoring is a separate question. OBS can route a source to a configured listening device so you hear it on headphones or speakers, but not hearing that monitor does not by itself prove that YouTube receives no sound. Conversely, hearing a local monitor does not prove the encoder is sending the same signal. Check the mixer and a viewer-facing test separately.
If you want local listening, use the mixer’s monitoring controls and select the intended monitoring device in OBS audio settings. Avoid sending monitored audio back into a desktop capture source that is also in the stream, since that can create duplicate or echoing audio. The Audio Mixer Guide covers mute, volume and monitoring controls. Keep this distinction in mind if the problem report is simply “I cannot hear it on my laptop”: local monitor silence and audience silence are not interchangeable symptoms.
For an always-on channel, this is also a good moment to document a known-good scene and source arrangement. If a late-night restart or scene change is part of the workflow, compare it with the practical notes on keeping a Hindi ASMR stream live overnight from a laptop. The point is not to copy another channel’s settings, but to know which scene and source are supposed to be active when you troubleshoot.
5. Read YouTube Live Control Room errors
Once OBS is producing a plausible signal, inspect the Live Control Room for the stream’s health messages and preview. YouTube’s specific no-audio wording is “Your encoder is sending no audio.” Treat this as a report about the signal reaching YouTube, not as a guaranteed diagnosis of the MP4 or proof that a particular OBS control is at fault. It means you should check the encoder’s audio output and any audio-enable option, as well as the upstream source path already covered.
YouTube Help’s live streaming error messages page gives guidance for this message and other ingest problems. Follow the precise message shown in your Live Control Room, because a codec, sample-rate or bitrate warning points to a different check than a no-audio warning. Do not infer that the MP4’s internal audio codec is automatically the same as the codec OBS sends in the live stream.
YouTube’s guidance says the incoming stream should have one audio stream; multiple audio streams may cause ingestion problems. If you see a relevant warning, check OBS output and any audio tracks configured for the broadcast. You do not need to add extra tracks simply because a file has separate audio components. Keep the live output straightforward while identifying which track carries the intended programme audio.
YouTube’s live stream troubleshooting page is another primary reference for tracing encoder and routed-source issues. The message may take some time to appear after starting a stream, so allow the preview and health indicators to update, but do not leave a long-running channel unattended before you have verified viewer-side sound.
6. Verify audio settings and routing
If the source meter moves and YouTube still reports no audio, inspect the path from OBS’s mixer to its encoded output. Confirm that the Media Source’s audio is included in the stream mix and that the selected output track is the one being sent. OBS configurations can differ, especially where advanced audio properties or multiple tracks are in use. A local monitor route is not a substitute for checking the encoded output route.
Check the stream’s audio format against YouTube’s current encoder guidance. YouTube lists AAC or MP3 as supported audio codecs in its live guidance and provides specific error messages for unsupported codecs or incorrect sample-rate and bitrate settings. Use the settings appropriate to the stream and the current Live Control Room feedback; do not guess at values from an unrelated setup or assume that changing the MP4 itself will fix an encoder-output error.
YouTube’s encoder settings, bitrates and resolutions guidance recommends testing and describes the encoder settings to use. Its error-message guidance is the better place to match a displayed ingestion warning. Where YouTube reports an audio setting problem, compare the setting it names with OBS’s output configuration rather than changing video parameters without a reason.
Routing can become confusing when a channel includes a Media Source, microphone, browser audio, desktop capture and a monitoring device. For diagnosis, simplify the mix: keep the expected source active, ensure it is not muted, and temporarily avoid unnecessary audio sources. This makes it easier to tell whether the MP4 alone reaches the encoded stream. Restore other required sources after the test and confirm that their levels remain appropriate.
If you are deciding whether to keep a computer-based OBS workflow, compare the work involved in preparing and maintaining it with other approaches. The overview of software for streaming prerecorded videos around the clock is useful context, but it does not replace checking the actual signal path in your own channel. If the recurring problem is that a computer must stay available to keep the broadcast running, StreamNeo addresses that specific operational burden by letting you upload a file and run the YouTube broadcast without leaving your own computer on.
7. Run a short test and listen from YouTube
After any correction, make a short test stream before relying on the loop for a full session. Choose a segment with clear, expected sound and confirm the OBS meter responds. Then look at the Live Control Room preview and listen to the YouTube playback from a separate viewer device or browser where practical. This checks more of the route than listening only to OBS monitoring.
YouTube recommends test streams that include audio and checking the Live Control Room preview; its live streaming tips also advise monitoring sound and picture. Listen long enough to hear the portion you selected, not only the first moment of the broadcast. If the file loops, check that playback continues as expected at the restart and that the audio returns with the picture.
Use what you hear to choose the next branch. If the file is silent in a player, replace or repair the media. If the file plays but the OBS meter remains inactive, focus on the source and playback. If the OBS meter moves but YouTube gives no sound or a no-audio warning, inspect the output track and encoder settings. If YouTube playback has sound but your headphones do not, troubleshoot local monitoring separately.
Do not treat a successful brief test as a promise that a long broadcast cannot fail later. Keep the test representative of the actual scene, file and routing you plan to use, and check the channel’s preview after changes to those elements. For a channel that depends on an overnight loop, make the test before the audience is relying on it rather than discovering a silent output after the fact.
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FAQ
OBS plays the MP4 picture, but the Media Source meter does not move. What should I check first?
Play a known audible section of the exact file outside OBS and confirm it contains an audio track. Then check that the active scene’s Media Source points to that file and is actually playing. If those checks pass, investigate the source’s handling of the media before changing YouTube settings.
YouTube says, “Your encoder is sending no audio.” Does that prove the MP4 is silent?
No. That is YouTube’s wording for audio not arriving in the incoming encoder stream; it does not identify the first point of failure. Check the MP4, OBS source and mixer, then the encoded output and any audio settings indicated by Live Control Room.
The OBS meter moves, but I cannot hear the stream on my headphones. Is YouTube silent too?
Not necessarily. OBS monitoring to your local listening device is separate from what a viewer receives. Check that the monitor device and routing are set as intended, then listen to the YouTube preview or playback to test the audience-facing signal.
The file loops correctly, so why does the sound still fail?
Looping restarts playback at the end of the file; it does not confirm an audio track exists or that the source is routed into the live output. Check the source meter during an audible passage and test the YouTube playback, including the loop restart, before depending on a long-running stream.