Audiplex M3 - Fix No Sound – Avantree Support

No sound from your Audiplex M3 may be caused by an incorrect audio input, an invalid source signal, a receiver that is not connected to the transmitter, or low listening volume. Follow the 3 steps below to restore sound.

Check the Transmitter's Audio Signal

Turn on the Audiplex M3 transmitter and play audio from your TV, mixer, computer, or other source. Check the OPT / AUX indicator.

Solid White

A valid audio signal is detected. Continue to Step 2.

Flashing White

No valid audio signal is detected. Check the cable, input selection, and source settings below.

Check this first: The transmitter's input must match the cable you are using. Press the OPT/AUX input button once to switch between Optical and AUX.

I'm Using an Optical Cable

Connect the cable from the TV's Optical / Digital Audio OUT to the transmitter's OPT input.
Select OPT on the transmitter.
Open the TV's sound settings and select Optical / Digital Audio Out.
Set Digital Audio Output Format to PCM or Stereo PCM.
Play a TV program and check whether the OPT indicator becomes solid white.

Important: Dolby Digital, DTS, Bitstream, or Auto may prevent the transmitter from detecting compatible audio.

Find PCM Settings for Your TV Brand →

I'm Using AUX / 3.5 mm Audio

Connect the audio source's Headphone / Audio OUT to the transmitter's AUX input.
Select AUX on the transmitter.
Play music or speech from the audio source.
Increase the source's output volume to a normal listening level.
Check whether the AUX indicator becomes solid white.

Tip: If the AUX indicator flashes only during quiet passages, test using continuous music or speech before assuming the connection has failed.

I'm Using Bluetooth as the Audio Source

Press the transmitter's Bluetooth button to select Bluetooth input mode.
Open Bluetooth settings on your phone or other audio source.
Connect to the Audiplex M3 transmitter using the name shown during Bluetooth discovery.
Check the Bluetooth indicator:
- Solid blue: Bluetooth connected.
- Blinking blue: Bluetooth mode is active but the connection needs attention.
Play audio and increase the source volume.

Important: The Bluetooth input connection and the transmitter-to-receiver connection are separate. Check Step 2 as well.

Check the Receiver Connection and Channel

If the transmitter is receiving audio but your listener still hears nothing, check the receiver and the transmitter's output channel.

Make sure the Audiplex M3 receiver is charged and turned on.
Keep the receiver near the transmitter while testing.
Check the transmitter's numbered 1 / 2 / 3 / 4 output channel indicators.
Confirm the receiver is connected to the intended transmitter and channel.
If several transmitters are nearby, make sure the receiver is listening to the correct one.

Expected: The receiver is connected to the intended transmitter, and the transmitter's active output channel is indicated.

Receiver Is Not Connecting

Confirm both the transmitter and receiver are powered on.
Move the receiver closer to the transmitter.
Restart the receiver and allow it to reconnect.
If the receiver was previously used with another transmitter, check its channel and connection settings.
If you need to add a new compatible receiver, use the transmitter's Add New Device control.

Note: On the transmitter, the Add New Device function is activated by holding its designated button for approximately 2 seconds. This is different from selecting the audio input.

Identify the Transmitter and Receiver Controls →

Several Transmitters Are Nearby

Audiplex M3 supports multiple output channels. A receiver listening to a different transmitter or channel may not play your intended audio.

Identify which transmitter is connected to your audio source.
Check its active numbered output channel.
Set the receiver to the intended channel using its supported controls.
Test the sound again.

Audiplex M3 Interactive Setup Guide →

Check the Earphones and Listening Volume

Plug the wired earphones securely into the receiver's 3.5 mm headphone jack.
Make sure the earphones are inserted fully and are not damaged.
Increase the receiver's listening volume gradually.
Make sure the TV, mixer, or other audio source is playing sound.
Test with speech or music you can clearly identify.

Expected: The transmitter receives valid audio, the receiver is connected to the correct channel, and sound plays through the wired earphones.

Only One Receiver Has No Sound

Check the affected receiver's battery level and power.
Confirm its channel matches the intended transmitter.
Try a different pair of wired earphones.
Increase its listening volume.
Compare it with a receiver that is working normally.

Diagnostic tip: If another receiver works with the same transmitter, focus on the affected receiver, its channel, volume, and earphones.

All Receivers Have No Sound

Return to the transmitter's audio input indicator.
If OPT or AUX is flashing white, fix the source signal first.
Confirm the transmitter's output channel and connection status.
Restart the transmitter and test one receiver nearby.
If available, try a different audio source or cable.

Diagnostic tip: If every receiver is silent, the problem is more likely to involve the shared audio source, transmitter, or channel configuration.

Sound Works, but Is Very Quiet or Distorted

Adjust the receiver volume to a comfortable level.
For AUX input, check that the source volume is not too low or excessively high.
If using a mixer, check the output level and avoid clipping.
Test with normal speech to compare the sound quality.

More Audiplex M3 Troubleshooting →

Still Need Help?

Please tell us your audio source (Optical, AUX, or Bluetooth), whether the input indicator is solid or flashing, the active transmitter channel, and whether the issue affects one receiver or all receivers.

ASK A QUESTION