LG S90QY Rear Speakers Not Working: What This Usually Means
If your LG S90QY rear speakers are not working, the issue is usually caused by pairing, sound mode, wiring, firmware, or signal interference rather than a permanent hardware failure.
This guide walks through the most common causes and the exact checks that help restore surround sound quickly.
The LG S90QY is a Dolby Atmos and DTS:X soundbar system designed to create a fuller surround field when the rear speakers and subwoofer are connected correctly.
Because the rears depend on wireless communication and system settings, even a small configuration problem can make them seem silent.
How the LG S90QY rear speaker system is supposed to work
The LG S90QY uses a soundbar, wireless subwoofer, and rear speaker kit to distribute audio across the room.
The rear speakers do not play every sound all the time; they are most active during content mixed with surround channels, such as Dolby Digital, Dolby Atmos, DTS, or supported game audio.
That means a quiet rear speaker does not always indicate a defect.
In many cases, the system is receiving stereo audio, the surround channel is inactive, or the rear level is turned down in the app or menu.
Quick checks before troubleshooting deeper
- Confirm the soundbar is powered on and not muted.
- Check that the rear speaker amplifier or wireless receiver has power.
- Verify the rear speakers are connected to the correct left and right terminals.
- Make sure the sound mode is set to a surround-capable mode.
- Test with known Dolby Atmos or 5.1 content, not just TV news or stereo music.
These basics solve many cases where the LG S90QY rear speakers are not working, especially after a move, reset, or input change.
Check the rear speaker connections first
If your rear speakers use wired connections to a wireless receiver or amplifier module, inspect each cable end carefully.
Loose banana plugs, partially inserted wires, or reversed polarity can reduce output or stop a channel entirely.
Look for the following:
- Positive and negative terminals matched correctly on both speakers.
- No frayed speaker wire strands touching adjacent terminals.
- The receiver unit powered by its original adapter.
- Indicator lights on the rear module showing normal status.
If a power light is off or blinking in an unusual pattern, the receiver may not be paired, may not have power, or may be unable to communicate with the soundbar.
Verify wireless pairing and speaker status
The LG S90QY rear channel module depends on a wireless link to the main bar.
If that link fails, the rear speakers may drop out entirely or play intermittently.
Re-pairing the system often restores normal operation.
To troubleshoot wireless pairing, power cycle the soundbar, rear module, and subwoofer by unplugging them for about 60 seconds.
Then reconnect power and wait for the rear unit to establish a link.
If the rear speaker light remains amber, flashing, or otherwise abnormal, consult the manual for the pairing state specific to your model variant.
Keep the rear module within a reasonable distance of the soundbar and away from large metal objects, routers, cordless phone bases, and thick walls.
Wireless dropouts are more common when the module is placed behind furniture or near congested Wi-Fi equipment.
Why the rear speakers may be silent in stereo content
Many users discover the LG S90QY rear speakers not working while watching cable TV, YouTube, or music streaming apps.
In many of those cases, the content is only stereo, so the rears are not expected to carry much audio unless a surround upmixing mode is active.
Try a source that explicitly supports surround sound, such as:
- Dolby Atmos movies on Netflix, Disney+, or Apple TV+.
- 5.1 test tracks or demo content.
- Modern console games with surround output enabled.
If the rears work with Atmos content but not with regular TV audio, the soundbar is likely functioning correctly.
You may just need to enable an upmixing setting or accept that the source has limited rear-channel information.
Adjust rear speaker level and sound settings
LG soundbars typically allow separate adjustment of rear speaker volume, center channel, bass, and height effects through the remote, on-screen menu, or companion app.
If the rear level is set too low, the speakers may appear dead even though they are working.
Check these settings:
- Rear speaker level or surround level.
- Sound mode selection such as Standard, Cinema, AI Sound Pro, or Bass Blast.
- AV Sync or delay settings that may affect perceived timing.
- Upmixing or surround enhancement features.
For testing, raise the rear level slightly and switch between sound modes to see whether the channel becomes audible.
Some modes prioritize front imaging and can make rear output feel weaker.
Update firmware and refresh the system software
Firmware issues can affect wireless communication, speaker detection, and audio decoding.
LG periodically releases updates that improve stability, HDMI eARC compatibility, and wireless performance.
Use the LG ThinQ app or the soundbar’s supported update method to confirm the system is current.
After updating, restart the entire setup and retest the rear speakers.
If the problem began after a TV firmware update or input change, a reset may help the devices renegotiate audio output properly.
Inspect TV audio output and HDMI eARC settings
Even if the soundbar is fine, the TV can block surround audio from reaching it.
The LG S90QY performs best when connected through HDMI eARC, with the TV audio output configured for passthrough or bitstream where supported.
Check the TV menu for the following:
- Audio output set to the soundbar or HDMI eARC.
- Digital sound output set to Pass Through, Auto, or Bitstream.
- Internal TV speakers disabled.
- CEC/Simplink enabled if required by your setup.
If the TV is converting everything to stereo PCM, the rear speakers may receive little or no signal.
Testing another HDMI source directly into the soundbar can help isolate whether the TV or the soundbar chain is causing the issue.
Reduce interference and improve rear speaker reliability
Wireless rear systems are sensitive to interference from routers, mesh nodes, microwaves, baby monitors, and dense wireless neighborhoods.
If your rear speakers cut out randomly, the issue may be environmental rather than mechanical.
Practical improvements include:
- Moving the wireless receiver away from the Wi-Fi router.
- Changing the soundbar and router placement to reduce overlap.
- Keeping power cables separated from speaker cables where possible.
- Avoiding enclosed cabinets that trap heat and block signal.
If the rear channel works only when the module is very close to the soundbar, interference or range is the likely cause.
Use a reset when settings changes do not help
A factory reset can clear corrupted pairing data or bad configuration states.
This is especially useful after power outages, app glitches, or multiple failed setup attempts.
Resetting should be considered after you have checked cables, firmware, sound modes, and TV output settings.
Before resetting, note your preferred sound settings because they will need to be reconfigured.
After the reset, pair the system again and test with known surround content before making any further adjustments.
Signs the rear speakers may actually be failing
Most LG S90QY rear speaker complaints are caused by setup issues, but hardware failure is possible.
You may be dealing with a failing speaker, cable, or wireless receiver if one channel never works even after re-pairing and swapping positions.
Watch for these warning signs:
- One rear speaker is silent regardless of content.
- The issue follows the speaker when moved to the opposite channel.
- Static, crackling, or frequent dropouts occur on one side.
- The rear module shows no power or pairing light despite correct power delivery.
Swapping left and right rear speaker connections is a useful diagnostic step.
If the problem stays with the same speaker, the issue is likely in the speaker itself or its wire.
If it follows the channel, the receiver or channel output may be at fault.
When to contact LG support or a repair service
If the LG S90QY rear speakers are still not working after you have checked power, pairing, firmware, source audio, and TV settings, professional support is the next step.
LG support can help confirm whether your unit needs replacement parts, service, or advanced troubleshooting specific to your region and model revision.
Have the following information ready before contacting support:
- Exact model number of the soundbar and rear speaker kit.
- Firmware version if available.
- Description of indicator lights on the rear module.
- Which sources and cables you tested.
- Whether the issue affects both rear speakers or only one channel.
With those details, support can usually determine whether the problem is in the TV audio chain, wireless link, speaker wiring, or a failed component.
Common fixes to try in order
- Play confirmed surround content to verify the rears should be active.
- Raise rear speaker level and change sound modes.
- Check speaker wiring, polarity, and power to the rear module.
- Power cycle and re-pair the wireless rear system.
- Confirm HDMI eARC and TV audio output settings.
- Update firmware on the soundbar and TV.
- Move the wireless module away from interference sources.
- Perform a factory reset if configuration remains unstable.
Following this order helps isolate the cause efficiently and avoids unnecessary replacement of working components.