If you mean using an external microphone, mixer, or USB audio source, Larix Broadcaster for Android can bring compatible USB OTG audio into the live programme. That is different from sending a second audio track that viewers can choose; the official Larix and YouTube materials reviewed here do not document that workflow.
The practical route is to check your phone and audio device together, enable Larix’s USB Camera feature, connect the stream to YouTube Live, and test the result before your event. USB OTG support is experimental, so treat the test as a compatibility check, not a formality.
External audio input is not an alternate track
An external input is sound from outside the phone—perhaps a microphone, mixer output, or audio interface—fed into the programme that Larix sends to YouTube. Viewers hear that as the stream’s audio. It does not, by itself, create a language option or a separate music-and-commentary choice in the YouTube player.
“External audio track” is sometimes used to mean either of these things. For the setup in this guide, think of it as an external audio source mixed into the outgoing programme. Softvelum documents an Android USB OTG path for compatible devices, but the reviewed documentation does not establish that Larix sends viewer-selectable alternate audio tracks. If you need that specific playback feature, check current official Larix and YouTube documentation for a supported multitrack workflow before planning around it.
This distinction matters if, for example, you want to add a bhajan singer’s microphone to a devotional stream. That is an input question. If you want viewers to switch between the original recording and a translated narration, that is a separate-track question. Do not assume the first setup gives you the second.
For other parts of a planned broadcast, such as picture quality, see the practical checks in this guide to a YouTube stream stuck at 360p. Picture quality and audio routing are separate, but testing both before a scheduled stream helps you identify which part of the chain needs attention.
What you need for USB OTG audio
You need an Android phone, Larix Broadcaster, an audio source, and a USB connection that the exact phone and source can use for audio capture. Depending on the phone connector, that path may include a USB-C OTG adapter. The adapter alone is not a guarantee: the phone must support USB host/OTG, and the connected device must be compatible with Android audio capture and Larix’s documented USB workflow.
Softvelum describes UVC OTG USB devices as usable for video and audio sources in Larix, while marking the feature experimental. Its USB OTG instructions give the app setup path. That warning is important when choosing hardware: a connector that physically fits is not proof that a microphone or interface will work with your handset.
Before buying or assembling a chain, check the phone manufacturer’s information for USB host support and the audio device’s documentation for Android or UVC audio compatibility. Also check the kind of output the source provides. A microphone-level signal and a mixer’s line-level output are not interchangeable assumptions; follow the source maker’s guidance on output and connection. If you need several microphones, confirm how they will be combined before they reach the phone. This setup guide does not establish a universal input selector or a universal way to mix multiple sources.
Power is another practical constraint. A phone, adapter, and USB audio device may draw power differently, and a long session is less forgiving than a short bench test. Check whether the device needs external power and whether the chosen connection can keep the phone charged without disrupting USB host mode. Confirm the arrangement with the exact cable and source you plan to use, rather than relying on a similar-looking device.
If the programme uses a prerecorded visual loop rather than a camera, keep the sound source and the video plan in view as separate jobs. The article on running a recorded IELTS lesson stream covers a different continuous-video use case; for this Larix setup, the key question is whether the incoming audio reaches the programme cleanly.
Connect the source to your Android device
Start with the audio source switched off or muted if its output could produce a loud signal when connected. Assemble the connection in the order recommended by the device maker. If the phone has USB-C and the source uses another connector, use an OTG adapter only where required and supported. Avoid adding extra adapters or hubs unless your device documentation calls for them; each added connection is another point to check if the phone does not recognise the source.
Next, check the physical chain: plugs are seated, cables are in the intended input and output sockets, and any required external power is present. For a mixer, verify that the output you are using is appropriate for the receiving device and set a conservative level before raising it gradually. A phone may recognise a USB accessory without the whole signal chain being correctly routed, so recognition alone is not an audio test.
Softvelum’s USB instructions describe enabling the feature in Larix under Advanced settings → USB Camera and restarting the app. Follow that sequence after connecting the supported device. The documentation also notes that it may be necessary to tap the camera ON/OFF control to initialise the USB camera. Since the feature is experimental, menus and behaviour can vary with Larix and Android versions, phone maker, and the connected hardware.
Do not infer that you should see a particular, universal list of microphone inputs or routing controls. The documented path is to enable USB Camera, restart, and, if needed, toggle the camera control to initialise the device. If your Larix version does not present the expected behaviour, check the current Softvelum instructions and the device-specific guidance rather than improvising a setting that is not documented.
Select and configure audio in Larix Broadcaster
Open Larix after enabling USB Camera and restarting it. Confirm that the app has initialised the connected USB device, using the camera ON/OFF action if needed as described by Softvelum. Then make a short local or private test and observe any audio indication the app provides. The exact controls available may depend on the app version and device combination, so do not assume that every installation exposes an identical selector.
Larix’s Android overview says Android audio is encoded as AAC outside WebRTC. YouTube’s encoder guidance accepts AAC or MP3 audio for standard live ingestion and recommends 128 Kbps for stereo. These are encoding facts, not a guarantee that a particular USB input will be captured correctly. Use the settings available in your version and check the result in YouTube’s preview rather than treating an encoder setting as proof of good sound.
Set levels at the source first, then adjust any available Larix controls conservatively. Listen for distortion when the loudest part of the programme occurs, not only during quiet speech. If a mixer is feeding the phone, keep its output from clipping and avoid turning up a noisy signal at the phone to compensate. A clean, moderate source level is easier to diagnose than a distorted one.
For a stream with music and speech, test both together. A microphone that sounds acceptable during a quiet introduction may become harsh when music starts, while a mix that works on headphones may be unbalanced on a phone speaker. Check left and right channels as well: a source or cable issue can leave one side missing. Larix’s audio encoding does not repair problems already present in the incoming signal.
Connect Larix to YouTube Live
In YouTube Studio, open the Live Control Room and create or select the live stream you intend to use. For an encoder-based broadcast, YouTube provides a stream URL and stream key. Enter the values supplied for that event in Larix’s connection settings. Prefer the RTMPS URL if Larix supports it for your setup; use the value YouTube provides rather than assuming a fixed endpoint. YouTube explains the encoder connection flow in its live-streaming help and its RTMPS guidance.
Treat the stream key as a password. Do not include it in a screenshot, public note, or message to someone who does not need access. If you think it has been exposed, replace it through YouTube Studio and update Larix before the next broadcast. The key connects the encoder to the event; it does not configure your external audio source.
Before starting a public event, check the selected YouTube stream and its privacy or visibility setting. An unlisted or private test can be useful where appropriate, provided the people who need to inspect it can access it. YouTube’s first-time live activation may take up to 24 hours according to YouTube Help, so do not leave initial account setup until the scheduled start. That timing concerns live-stream activation, not audio configuration.
If you are planning a continuous programme rather than a one-off phone stream, think through how the source will remain connected and monitored during the full run. A phone-based setup can be suitable for a short live session, but the person operating it must account for charging, app state, and the physical audio connection. A 24/7 Nepali music stream plan offers a separate example of continuous-channel planning; it does not change the compatibility checks for this USB input.
Test audio before going live
Do a test before the audience is waiting. Start Larix with the source connected and send a short test to a private or unlisted YouTube stream if that suits your workflow. First check for activity or meter movement in Larix, if available. Then inspect YouTube’s Live Control Room preview, because the preview confirms that audio is reaching YouTube rather than merely appearing active on the phone.
Listen to the preview on headphones and, if possible, another ordinary playback device. Check for silence, clipping, hum, intermittent dropouts, excessive room noise, and missing left or right channel. Speak at the distance you will use during the event and play the loudest music or source material at its expected level. A brief voice check alone may not reveal distortion that appears when the mixer output rises.
Give the test enough time to include the actions you will repeat during the real stream: mute and unmute, adjust the source, and confirm that audio returns after a pause. If audio is important to a long session, repeat the check after the phone has been connected to power and the device has been running for a while. The purpose is not to claim that every future session will behave identically; it is to catch a faulty cable, poor level, or incompatible combination while there is still time to change it.
YouTube’s live encoder settings guidance is the place to check current ingestion requirements. Keep the distinction clear: the service’s codec and bitrate guidance concerns the stream sent to YouTube. The actual sound quality still depends on the source, the physical connection, gain staging, and the capture path.
Troubleshoot missing or distorted audio
If there is no sound, work from the phone outward. Reseat the USB adapter and cable, confirm the source is powered and connected to the correct output, and check whether the Android device supports USB host/OTG. Verify that Larix’s USB Camera feature is enabled, restart the app, and try the documented camera ON/OFF initialisation step. Check any Android permission prompt rather than dismissing it without inspection.
If Larix appears to recognise the device but YouTube is silent, separate capture from delivery. Check for source activity and any audio indication in Larix first, then look at the YouTube preview. Re-enter the current stream URL and key if the connection itself is not active, taking care not to expose the key. If YouTube receives video but not sound, return to the source routing and Larix capture checks; changing the video resolution will not correct a disconnected audio input.
For distorted or noisy sound, reduce the source output and test again. Check for clipping at the mixer or interface, unsuitable level matching, a loose cable, electrical hum, or microphone placement too close to a loud source. Change one part of the chain at a time and listen to a fresh preview. If one channel is absent, test the source and cable separately where possible and check whether the source is mono or stereo and how its output is connected.
If the phone never recognises the source, test the same cable and device outside the event if you can, and consult the phone and accessory documentation for the exact combination. A different adapter may help only if the original adapter is the fault; it cannot make an unsupported phone or audio device compatible. Softvelum explicitly describes the OTG feature as experimental, so some combinations may not work properly. For an upcoming broadcast, use a source path you have verified rather than relying on a last-minute hardware change.
Choose a setup you can repeat
The useful comparison is not a long shopping list but whether each part of the chain is supported and testable. Check connector, host support, audio compatibility, source level, power needs, and the exact handset together. Keep a note of the working cable order and Larix settings once you have verified them; that makes it easier to restore the setup after the phone is disconnected.
For a fixed event, a mixer or USB source can bring an external microphone into the same programme audio, provided the chain works with the device. For a routine that depends on a phone remaining unattended or a long recorded file playing continuously, the operating burden is different: someone may need to maintain the handset, connection, and app state. When the recurring problem is keeping a file on air without leaving a computer running, StreamNeo can remove that specific operating task by turning an uploaded video into a YouTube live stream that runs with your own computer off. It does not change the requirement to verify an external input setup in Larix, and it is YouTube-only.
Once you have a working arrangement, keep the source, levels, and cables consistent for the event. If you replace a phone, update Larix, change the audio interface, or rebuild the cable chain, treat that as a new combination and repeat the test. A setup that passed once is useful evidence for that combination, not proof that every USB audio device will work.
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FAQ
Can I send a separate audio track for viewers to choose?
The documented Larix Android USB setup brings an external source into the programme audio. The official materials reviewed for this guide do not document a separate viewer-selectable alternate track, so verify a supported multitrack workflow separately if that is what you need.
Does every USB microphone or mixer work with Larix on Android?
No. Softvelum describes USB OTG support as experimental, and compatibility depends on the phone, Android version, device, and connection path. Check the exact hardware documentation and test the complete chain before relying on it.
Where is the USB audio setting in Larix Broadcaster?
Softvelum documents Advanced settings → USB Camera. Enable it and restart Larix; the camera ON/OFF control may need to be tapped to initialise the USB device.
How do I know the audio is reaching YouTube?
Check the source and any audio indication in Larix, then listen to the Live Control Room preview. The YouTube preview is the final practical check that the encoder’s audio is arriving at the platform.