Optical cable
- Sound Output
- Optical / External Speaker
- Digital Audio Format
- PCM or Stereo
Interactive User Guide · Aura Focus / BTHT-4250
Clear, low-delay TV sound through in-ear Auracast earbuds.
Connect the transmitter by Optical or AUX. If your TV only has HDMI ARC/eARC, add a HAX06 HDMI-to-Optical adapter first.
For normal TV listening, power the transmitter and remove the earbuds from the case—no Bluetooth pairing is needed.
Secure in-ear fitAuracast TV audioStart setup
What do you want to set up?
Choose the option that works best for you.
★ Use the transmitter for the lowest-delay TV listening experience.
How the recommended setup works
The transmitter broadcasts your TV sound.
TVYour TVOptical or AUX output
TXAura Focus transmitterReceives and broadcasts TV sound
HPAura Focus earbudsJoins the Auracast broadcast
For normal TV use, do not pair by Bluetooth. Solid blue for 1 second, then off, means the earbuds joined the transmitter.
Got it — Start setupRecommended kit setup
Four steps. One clear result.
Follow each step in order. We show what to do, what to look for, and how to fix it.
Step 1
Power the transmitter.
Place it near the TV. Keep the audio cable loose, not stretched.
Connect power
- Connect USB-C to the transmitter.
- Connect USB-A to a 5 V, 500 mA–2 A power source.
✓
Expected: the transmitter turns on. The audio-signal light may blink until the TV sends sound.
No light? Reconnect both cable ends. Then try another USB power source.
Step 2
Choose one TV audio output.
Look at the labels on the back or side of the TV, then choose the matching path.
Using a soundbar? Aura Focus has no soundbar passthrough. Complete the earbud setup first, then review the TV speakers and soundbar section.
Which TV output do you have?
Tap the socket label you see. Only HDMI ARC? Choose HAX06.
Connect with Optical
- Remove the protective caps from both cable ends.
- Connect TV OPTICAL / DIGITAL AUDIO OUT to transmitter OPT IN.
- Confirm the transmitter Audio Input light is solid white.
Next: set the TV sound output to Optical/External Speaker and Digital Audio Format to PCM.
Connect an HDMI-only TV with HAX06
- Connect the TV port labeled HDMI ARC or eARC to the HAX06 adapter.
- Connect HAX06 OPTICAL OUT to Aura Focus OPT IN.
- Confirm the transmitter Audio Input light is solid white.
Important: Aura Focus does not support HDMI ARC directly. On the TV select HDMI ARC/Receiver, turn eARC off if required, and choose PCM/Stereo.
Connect with AUX / 3.5 mm
- Connect TV HEADPHONES / AUDIO OUT to transmitter AUX IN.
- Confirm the transmitter Audio Input light is solid white while audio plays.
- Set TV sound output to Earbuds and raise TV volume to a normal level.
Next: play a program with speech; PCM is normally not required for analog AUX.
Step 3
Set the TV audio output.
Use your TV remote. Then match the settings to your cable.
Use your TV remote controlThese settings are changed on the TV—not on the Aura Focus transmitter.
Choose the card that matches your cable
3.5 mm cable
- Sound Output
- Earbuds
- TV volume
- Raise to a normal level
No PCM setting needed.
HDMI cable
- Sound Output
- HDMI ARC / Receiver
- eARC
- Off
- Digital Audio Format
- PCM or Stereo
Optical / HDMI ARC:Choose PCM. Dolby, DTS, Bitstream, or Auto may cause silence.
✓
Test it: play a TV program with speaking voices.
Find PCM settings for your TV brand
Step 4
Listen with the earbuds.
Remove both earbuds from the charging case. They automatically join the transmitter's Auracast broadcast.
✓
Success: each earbud LED is solid blue for 1 second, then turns off. TV sound plays.
Join the TV broadcast
- Keep the powered transmitter close while first connecting.
- Remove both earbuds from the charging case.
- Wait for solid blue for 1 second, then wear them.
- Raise the earbud volume slowly.
Red + blue flashing? The earbuds are in Bluetooth mode. Turn the transmitter on, then place the earbuds back in the case and remove them again.
Only one side has sound? Reseat both earbuds in the case, then remove both again.
Need another listener? Go to Add More Earbuds. If an extra receiver will not join, check the FAQ link.
Bluetooth TV setup
Connect the earbuds directly to a Bluetooth-enabled TV.
Use this option without the Aura Focus transmitter. Bluetooth TV audio may have more delay.
Turn off the transmitter
Keep the Aura Focus transmitter off while pairing directly with the TV.
Start Bluetooth pairing
Open the charging case and hold the case button for 2 seconds until red and blue flash.
Select Aura Focus on the TV
Open the TV Bluetooth speaker or headphone list and select Aura Focus.
Confirm the connection
Solid blue means the Bluetooth connection is ready. Start TV playback and raise the TV volume if needed.
Expected: TV sound plays through both earbuds.
Next: Adjust Volume →Want lower-delay TV sound and Volume Boost?
Adjust volume
Adjust volume from the earbuds, transmitter, or TV.
Use one deliberate tap on an earbud and pause briefly between taps.
1 On the earbuds
- Single-tap the left (blue) earbud: Volume −
- Single-tap the right (red) earbud: Volume +
2 On the transmitter
- Use the + / − buttons.
3 On your TV (if available)
- Optical: TV volume may be fixed.
- AUX: use the TV remote.
4 Volume too low with Optical?
- Switch OPT Volume from Normal to Boost.
Listen with earbuds
Get a secure, comfortable fit.
Start with the medium ear tips. Change size only if an earbud feels loose or uncomfortable.
Insert
Place each earbud in the matching ear.
Rotate
Turn it gently until it sits securely.
Check
Shake your head lightly. If it moves, try another tip size.
Good fit: secure, comfortable, and clear sound.
What do the 3 white dots mean?
They show the charging case battery level.
Where do I tap?
Tap the round silver area once: left = Volume −, right = Volume +.
Advanced · Optional
Use as Bluetooth earbuds.
- 1
Turn off the transmitter.
- 2
Open the case. Hold the case button for 2 seconds. LEDs blink red & blue.
- 3
Turn on Bluetooth on your phone or PC. Select Aura Focus.
✓LED turns solid blue for 1 second, then off.
Quick fixes
Match what you see.
Each fix states the action, expected result, and next step.
⌁Earbuds won't join the transmitter
- Confirm the transmitter is powered on and playing TV audio.
- Place both earbuds in the charging case, close it for 5 seconds, then remove both together.
- Keep the earbuds close to the transmitter while they reconnect.
Expected: each earbud shows solid blue for 1 second, then its light turns off and TV sound plays. If not, submit a support ticket with the LED pattern.
🔇Joined, but no TV sound
- Check the cable: use TV audio OUT and connect it to transmitter OPTICAL or AUX.
- HDMI-only TV: connect HDMI ARC/eARC to HAX06, then HAX06 Optical OUT to transmitter OPT IN.
- Check the TV: Optical or HAX06 requires PCM/Stereo. AUX requires Headphones output and normal TV volume.
- Restart: turn the transmitter OFF, then ON.
Expected: the Audio Signal light is solid and dialogue plays. If it still blinks, recheck the selected TV output.
ARCTV only has HDMI ARC / eARC
- Aura Focus does not accept HDMI directly.
- Connect TV HDMI ARC/eARC to the HAX06 adapter.
- Connect HAX06 Optical OUT to transmitter Optical input.
- On the TV choose HDMI ARC/Receiver, turn eARC off if required, and select PCM/Stereo.
Expected: the Audio Signal light becomes solid. A standard HDMI cable connected directly to Aura Focus cannot work.
◉Charging-case middle light blinks, side lights stay solid
- Place both earbuds fully into the charging case and confirm their contacts are seated.
- Connect the case to USB-C power or place it correctly on the powered charging dock.
- Leave it charging for about 2 hours, then remove and reinsert both earbuds.
Expected: the three white case lights indicate the case battery level. If the middle light continues blinking abnormally after a full charge, submit a support ticket with a short video of the pattern.
±Volume taps respond slowly
- Tap the center of the round silver control once—left for volume down, right for volume up.
- Wait briefly for the volume step before tapping again.
- Dry the control surface and your fingertip, then retry.
Expected: each deliberate tap changes one volume step. If it remains unresponsive, use the transmitter + / − buttons and contact support.
⚡No light on transmitter
- Reconnect USB-C at both ends.
- Try a known-working 5 V USB adapter.
- Slide the transmitter switch to OFF, then ON.
If there is still no light, submit a support ticket with a photo of the power connection.
🔋Earbuds will not charge
- Confirm the dock has power.
- Align the charging contacts and look for solid red.
- Try USB-C charging directly.
- Allow about 2 hours.
Daily use
Charge the earbuds.
Use the powered dock or a USB-C cable.
Power & charging
About 2 hours for a full charge.
- Use the powered dock or USB-C with a 5 V, 1–2.4 A source.
- On the dock, align the charging contacts.
- Solid red means charging; the LED turns off when full.
Not charging? Reseat the earbuds or USB-C cable and verify the power source.
Battery reference
Up to 6 hours of playtime. Actual time varies with volume, connection, and use.
Share TV sound
Use TV speakers or a soundbar with Aura Focus.
The TV must support two audio outputs at the same time.
Possible when your TV supports simultaneous output.
- Connect Aura Focus to the TV Optical output.
- In TV Sound settings, choose TV Speaker + Optical, Simultaneous Optical Output, or Dual Audio Output.
- Set Digital Audio Format to PCM.
First check whether the TV has a second active audio output.
Not sure? Send us your TV and soundbar models →More listeners
Add compatible Auracast receivers.
Aura Focus can broadcast to as many as 100 compatible Auracast receivers. Other brands may require an Auracast-capable Android phone or companion app.
1. Start transmitter discovery
Hold ADD DEVICE on the transmitter for 2 seconds. Its light flashes orange rapidly.
2. Join from the receiver
For compatible Avantree receivers, follow that receiver's Auracast setup guide or companion app. For hearing aids or other brands, use their Auracast Assistant or companion app.
3. Confirm connection
Keep the receiver close while joining. Its own guide or app should confirm the Aura Focus broadcast is selected.
Important: classic Bluetooth headphones cannot join this Auracast transmitter.
Private listening
Private Mode is coming soon.
Private Mode uses an encrypted, password-protected Auracast broadcast.
What to expect
The feature is not available yet. Once released, it will be added to the earbuds through a DFU firmware update.
Until then
Use the open Aura Focus broadcast for normal TV listening. The headphone app is only needed for password-protected broadcasts.
In the box
Everything included.
Earbuds + transmitter dock
USB-C power cable
Optical cable
AUX cableHDMI ARC is not built in. For an HDMI-only TV, use a HAX06 HDMI ARC-to-Optical adapter (sold separately).
Reference
Connections, lights, and official help.
Quick reference
- TV inputs
- Optical PCM or 3.5 mm AUX
- HDMI ARC/eARC
- Not supported directly; requires HAX06 HDMI-to-Optical adapter
- Solid blue for 1 second
- Joined Auracast for 1 second, then LED off
- Red + blue
- Bluetooth pairing mode
- Charge time
- About 2 hours
- Maximum receivers
- Up to 100 compatible Auracast receivers
- Playtime
- Up to 6 hours
Official resources from the product page
FIRMWARE UPDATE
Update Aura Focus when a fix or feature requires it.
Not part of normal setup. Update only when Avantree Support recommends it or the official Aura Focus update page directs you to do so.
- 1Open the Aura Focus update pageCheck the available release and read all product-specific requirements first.
- 2Prepare the listed device and cableUse the device, computer, and USB data cable specified on the update page.
- 3Run the updateKeep the device connected until the updater confirms completion, then follow its restart or reset step.
During the update: do not unplug the device, close the updater, or turn off the computer.
STILL NEED HELP?
Get the right help for Aura Focus.
Choose Aura Focus / BTHT-4250 and include the TV model, connection type, LED pattern, and a clear photo of the TV and transmitter ports.
RECOMMENDEDSubmit an Aura Focus support ticketAdd photos or screenshots so the team can see the exact wiring and TV settings.Start support request →
DON'T WANT TO SUBMIT A TICKET?
