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Interactive user guide

Relay Setup Guide

Four steps. One clear result.

Relay sends 3.5 mm audio to your headphones. Pair them to Relay—not your phone.

Real airplane seatback entertainment screen with its audio control panel belowAirplane audio
Avantree Relay airplane Bluetooth transmitterRelay
Headphones

Pair headphones to Relay, not your phone.

Start SetupFix a problem

Keep both within 3 ft / 1 m while pairing.

1Headphones
2Relay
3Connect
4Play
1

Put your headphones in pairing mode

  1. Turn off Bluetooth on devices previously connected to your headphones, such as your phone or tablet.
  2. Put headphones in pairing mode (ready to connect).

    Turning them on is not enough.

    Headphone pairing helpChoose brand
    AirPods / AirPods Pro

    Check the back of your case.

    There is a button

    AirPods 1–3 / AirPods Pro 1–2

    1. Open the case with your AirPods inside.
    2. Hold the button on the back for about 5 seconds.
    AirPods case rear setup button held until the front status light flashes white

    Ready when: the case light flashes white.

    There is no button

    AirPods 4 or 5 / AirPods Pro 3

    1. Open the case with your AirPods inside.
    2. Double-tap the front of the case.
    AirPods 4 or 5, or AirPods Pro 3 case front double-tapped until the status light flashes white

    Ready when: the case light flashes white.

    AirPods Max

    Press and hold the noise control button for about 5 seconds.

    Ready when: the status light flashes white.

    Bose
    1. Turn on the headphones or open the earbud case.
    2. Hold the Bluetooth or power button until the light flashes blue or you hear “Ready to connect.”

    Ready when: the light flashes blue or the voice prompt confirms pairing.

    Beats
    1. Turn on the headphones.
    2. Hold the system or power button until the indicator flashes.

    Ready when: the indicator flashes for pairing.

    Sony
    1. With the headphones off, hold the power button for about 5 seconds.
    2. For Sony earbuds, use the case or touch-sensor pairing command for your exact model.

    Ready when: the light flashes blue or you hear “Bluetooth pairing.”

    Samsung Galaxy Buds
    1. Place both earbuds in the case, close it for 5–6 seconds, then open it.
    2. If pairing does not start, wear both earbuds and touch both touchpads until you hear the pairing sound.

    Ready when: the earbuds announce pairing or show their pairing pattern.

    JBL
    1. Hold the Bluetooth or power button until the indicator flashes rapidly.
    2. If JBL reconnects to a phone, turn that phone Bluetooth off and try again.

    Ready when: the indicator flashes rapidly.

    Other headphones
    1. Hold the power, Bluetooth, or main button until the light flashes rapidly.
    2. Check the headphone manual for the exact command if the light does not change.

    Ready when: the headphones show their documented pairing pattern.

  3. Check for a flashing pairing light or “Pairing” prompt.

Pair with Relay—not your phone.

DONEHeadphones are searching.
Next: Step 2 →

IF NOTNeed pairing steps? Choose your brand above.

2

Put Relay in pairing mode

  1. Switch Relay ON.
  2. Check Headphone 1 indicator for red + blue flashing.
    Pairing mode (ready to connect to headphones).

DONERed + blue flashing: Relay is searching.
Next: Step 3 →

IF NOTNot flashing red + blue? Hold MFB—the large round button—until Headphone 1 indicator flashes red + blue, then release.

3

Let them connect

  1. Keep both devices close — within 3 ft / 1 m.
  2. Wait for Headphone 1 indicator to stay solid blue.

DONEHeadphone 1 indicator Solid blue: your first pair is connected.
Next: Step 4 →

IF NOTStill red + blue? Check that your headphones are also in pairing mode and not connected to a nearby device. Open No connection →

4

Plug in and play

  1. Plug Relay into a 3.5 mm AUDIO OUT.
  2. Start the audio.
  3. Raise the volume slowly: source → Relay → headphones.
SourceAirplane screen→Relay+ / − buttons→HeadphonesVolume

Important: Use AUDIO OUT, not AUDIO IN.

DONESolid blue + sound.

Solid blue but no sound? Fix it →

More ways to use Relay

Reconnect next time

Already paired? You usually do not need to pair again.

  1. Turn off Bluetooth on nearby devices your headphones normally use.
  2. Turn on headphones and Relay.
  3. Wait 5–10 seconds for solid blue.
  4. Still disconnected? Press MFB once. Wait another 5–10 seconds.

Check: play audio and confirm you hear it. For two pairs, check both.

Still not connected? Open No connection →

Add a second pair of headphones

  1. Keep the first headphones connected. Confirm Headphone 1 indicator is solid blue.
  2. Hold Relay's MFB until Headphone 2 indicator flashes red and blue.
  3. Put the second headphones in pairing mode.
  4. Keep them close to Relay.
  5. Wait until both Headphone 1 indicator and Headphone 2 indicator stay solid blue.

DONEBoth Headphone 1 indicator and Headphone 2 indicator are solid blue. Play audio and confirm both pairs can hear it.

Both lights solid blue, but one pair has no sound?

A pair may be connected to another device or may not have reconnected correctly.

  1. Turn off Bluetooth on nearby devices the headphones normally use.
  2. Put earbuds into their cases and close the lids, or turn the headphones off.
  3. Switch Relay OFF. Wait about 5 seconds, then switch it ON.
  4. Take the earbuds out or turn the headphones ON.
  5. Wait for Headphone 1 indicator and Headphone 2 indicator to stay solid blue.
  6. Play audio and check both pairs.

Expected: both lights stay solid blue and both pairs play sound.

Still silent? Contact support and include both headphone models.

Charging & battery

  1. Connect the USB-C cable to Relay and a 5V / 1–2.4A USB power source.
  2. Charging: the battery indicators flash white.
  3. Fully charged: the indicators turn solid white, then switch off.

Check battery: double-click Relay’s MFB to display the battery level.

Check the battery indicators—not the blue headphone connection lights. If charging does not start, check the cable and power source, then contact support.

Firmware update

Firmware update

Update Relay

  1. Download the Firmware Update Tool on a Windows/Mac computer.

  2. Connect Relay to your computer with a USB data cable.

    Firmware update cable: Use the gray-tip cable (a USB cable that supports data transfer) that came with your device.
    Mac users can also use an Apple charging cable.

  3. Open the Firmware Update Tool.

    Follow the on-screen instructions.

    Keep Relay connected until it says Complete.

After updating: reset Relay.
Download Firmware Update Tool Notify me about updates

QUICK HELP

Fix common problems

01
No connection
  1. Turn off Bluetooth on nearby phones, tablets, and computers.
  2. Put your headphones in pairing mode again.
  3. Hold Relay’s MFB until the light flashes red + blue.
  4. Keep Relay and your headphones close together.

DONEThe Relay light turns solid blue.

02
Connected but no sound
  1. Push Relay’s plug fully into the headphone jack or AUDIO OUT.
  2. Start the audio. Raise the source volume.
  3. Press Relay’s + button to raise its volume.
  4. Raise your headphone volume.

DONESound plays through the connected headphones.

Still no sound?

  1. If available, test the same audio jack with wired headphones.
  2. No sound there either? Check playback, mute, and the source’s headphone output setting.
  3. Wired headphones work? Try Relay with another 3.5 mm audio output, if available, to narrow down the source or connection problem.

Still silent? More no-sound checks →

03
Clear pairing history
  1. Switch Relay ON.
  2. Hold + and − together for 6 seconds.
  3. Confirm red and blue stay on together for 3 seconds.
  4. Pair your headphones with Relay again from Step 1.

DONERelay's saved Bluetooth pairing history is cleared and the headphones can be paired again.

04
Audio delay

Why it happens

Some Bluetooth delay is normal.

Low latency needs both devices:
Relay and your headphones must support compatible aptX Low Latency or aptX Adaptive.

AirPods do not support these codecs.

Try this

  • Check your headphone model’s supported codecs.
  • Keep Relay close to your headphones.
  • Move away from crowded wireless areas.

Check the result

Play the same video again. Compatible low-latency headphones can reduce delay; some delay may remain.

More audio delay guidance →

More FAQs →