The Bass Module 700 receives its signal from the soundbar wirelessly, and Bose provides the timing control on the soundbar, not the module: in the Bose app the Smart Soundbar 600 and Smart Ultra Soundbar have an Audio Delay setting from 0 to 200 under Sync and Delay. If bass seems late compared with the rest of the soundbar, confirm the module's LED is solid white, then power-cycle it and check the soundbar's firmware, since Bose's soundbar firmware notes include performance fixes.
Differential
Likely causes of “Bose Bass Module 700 audio is delayed or out of sync”, and how to tell them apart
- 1
The module is reconnecting
What separates it Bass arrives noticeably late for a few seconds right after the soundbar wakes up
How to confirm Wait for the module LED to be solid white, then listen again
- 2
A soundbar-wide audio delay
What separates it Everything is late relative to the picture, not just the bass
How to confirm Adjust Audio Delay on the soundbar from 0 to 200 in the app
- 3
Wireless interference
What separates it Bass lags only in some rooms or at certain times
How to confirm Move the module closer or reduce nearby wireless devices
- 4
Outdated soundbar firmware
What separates it Timing between bass and dialogue worsened after the module was added or moved
How to confirm Update the soundbar's firmware in the Bose app, then retest the timing
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether the whole soundbar is late or only the bass
- The module's rear LED state during the problem
- The current Audio Delay value in the Bose app
Try in this order
0 of 5 completedConfirm it is a bass problem
ReversiblePlay a clip with a clear bass hit. If the whole soundbar is late, use the soundbar's Audio Delay; if only the bass lags, work on the module link.
Check the LED
ReversibleThe lower rear LED must be solid white. Blinking white means it is downloading an update, so wait.
Adjust the soundbar delay
ReversibleIn the Bose app tap Audio, scroll to Sync and Delay, choose Audio Delay and try values between 0 and 200.
Move the module
ReversibleBring the module closer to the soundbar, away from routers and other wireless devices, and retest with the same bass clip to see if timing improves.
Power-cycle
ReversibleUnplug the module's power cord for 30 seconds, reconnect it and wait 15 seconds for it to relink with the soundbar, then test the timing again.
Model-specific
What is true of this model and not of its siblings
- Optional accessory
- The Smart Soundbar 600's specification lists one optional bass module in its inputs and outputs, and the Ultra's LED article lists the Bass Module 700 alongside the soundbar's own lights.
- Placement
- Because the link is wireless, place the module within range of the soundbar with nothing metal or thick between them, and away from routers and other wireless devices. Low bass is also strongly affected by room position, so try a spot away from walls and corners before judging the sound.
- Tone and volume
- Bass level is adjusted on the host soundbar, and volume follows the soundbar's volume control, so muting the soundbar mutes the module. There is nothing to adjust on the module itself, which has no buttons, no microphone and no Bluetooth pairing of its own.
- Safety
- Bose has a separate article for smoke or a burning smell during normal use of the module. If that ever happens, unplug the module immediately, stop using it and contact Bose. Do not open the module or use an unlisted power cord when testing an outlet or cord.
- Updates
- The module updates as part of the host soundbar's system update: a blinking white LED shows it is downloading. Keep both powered and do not unplug during that time. The Smart Soundbar 600's latest firmware in Bose's list is 11.0.40 of 7 April 2026, which carries bug and security fixes.
Stop boundary
When this stops being a self-service repair
- !If bass lags on every source after a full reset of both devices, request service for the module
- !If the module LED shows an unlisted state, Bose says it requires service
Evidence ledger
Sources behind this answer
The rear LED states from off to white blinking.
Outlet, cord and LED checks.
Unplug 30 seconds and wait 15 seconds to reconnect.
The label on the bottom of the module.
The module works only with a host soundbar or console.
Refers to the host product's troubleshooting.
Refers to the host product's troubleshooting.
Refers to the host product's troubleshooting.
Tone is set on the host product.
The Connect step for an accessory bass module.
Disconnect the bass module and surround receivers during a reset.
The same accessory disconnect step for the Ultra.
Lists the Acoustimass 300 and Bass Module 700 LED states.
Exact questions
Common questions
Where is the delay setting?+
On the soundbar, under Sync and Delay.
What is the range?+
From 0 for no delay up to 200 for the maximum delay.
Does the module have its own delay?+
No, the soundbar's Audio Delay setting controls timing for the system.
What does blinking white mean?+
The module is downloading an update.
Can interference delay bass?+
Yes, nearby wireless devices can disturb the link and delay the bass.
Does the reset help?+
Yes, unplugging the module forces it to reconnect to the soundbar.
Will a firmware update help?+
It can, because Bose's soundbar firmware notes include performance fixes.
What should the LED show?+
Solid white on the rear LED means it is connected to the soundbar.