Harmony - Fix No Sound – Avantree Support

Before You Start: No sound may occur if a speaker is disconnected, the transmitter is not receiving audio, or the volume is too low.

Step 1 – Check the Speaker Connection

Turn ON the Harmony transmitter and speakers. Check the WHITE LED on each speaker.

Solid WHITE – Speaker connected. Continue to Step 2.

Flashing WHITE – Speaker is searching for a connection.

If the speaker keeps flashing WHITE:

Make sure the speaker is in Broadcasting Mode, not Bluetooth Mode.
Move the speaker closer to the transmitter.
Turn the speaker OFF and ON again. Wait a few seconds for it to reconnect.

How to Pair Additional Speakers →

Step 2 – Check the Transmitter’s Audio Signal

Play a TV program, video, or music. Check the OPT / AUX indicator on the transmitter.

Solid WHITE – Audio signal detected. Continue to Step 3.

Flashing WHITE – No valid audio signal detected. Follow the instructions below.

Select your audio connection. Make sure the transmitter’s side input switch matches it.

Optical – TV Connection

Important – Set Your TV Audio Format to PCM / Stereo.

Why PCM? PCM allows the Harmony transmitter to receive and play TV audio correctly. Other formats, such as Dolby, DTS, Bitstream, Auto, or Pass Through, may cause no sound.

Open your TV’s Settings → Sound / Audio:

Set Sound Output to Optical / Digital Audio Out.
Set Digital Audio Format to PCM / Stereo.

Find PCM Settings for Your TV →

AUX / 3.5 mm – TV Connection

Set your TV’s Sound Output to Headphones / Audio Out, if required.
Increase the TV volume and make sure it is not muted.

Bluetooth – Phone / Tablet Connection

Flashing RED and BLUE – Pairing mode.

Press and hold the transmitter’s Phone / Pair button for approximately 4 seconds.
Wait until the indicator flashes RED and BLUE.
On your phone or tablet, select Avantree Base Flex in Bluetooth settings.
Once connected, play audio to test.

Step 3 – Check the Cable, Volume & Restart

Check the cable connection: Use only one audio cable (Optical or AUX). Make sure it is securely connected to both the TV and transmitter.

Optical: Connect the optical cable to the transmitter’s Optical IN port.
AUX / 3.5 mm: Connect the AUX cable to the transmitter’s AUX IN port.

Increase the volume on the audio source, transmitter, and speakers.
Try another TV channel, video, or app.
Turn OFF the transmitter and speakers, then turn them back ON and test again.

Still no sound? If using Optical or AUX, try a new audio cable of the same type.

Still Need Help?

Contact Avantree Support and include your audio connection type, whether each speaker’s LED is solid or flashing WHITE, and whether the transmitter’s OPT / AUX indicator is solid or flashing WHITE.

Contact Avantree Support →