What Does This Error Mean?

Uneven left-right balance on a Bose stereo pair is usually caused by an incorrect left/right speaker assignment in the Bose Music app, or the speakers being placed at different distances from the listening position. Check the channel assignment in app settings and swap if needed — it is a common first-time setup mistake.

Affected Models

Bose SoundLink Flex (stereo pair)
Bose Home Speaker 300 (stereo pair)
Bose Home Speaker 500
Bose Soundbar 300
Bose Soundbar 700

Common Causes

Left and right speakers swapped in the app — L is assigned to the physical R position
Speakers at unequal distances from the listening position
Balance setting in the source device (phone or TV) offset from centre
One speaker in the pair has a lower volume than the other due to independent volume settings
Acoustic reflection from nearby walls creating perceived imbalance

How to Fix It

Check and swap the left/right assignment in the app.

In the Bose Music app, go to Settings for your stereo pair and find the Left/Right or Channel assignment option. Swap the assignment and listen again. Mistaken L/R assignment is the most common cause of perceived imbalance and is a one-tap fix.
Check the source device balance setting.

On your phone, go to Settings > Accessibility > Audio Balance (iOS) or Settings > Sound > Audio Balance (Android). Ensure the slider is centred. A balance offset on the source is often overlooked and causes the same symptom as a speaker fault.
Equalise the placement distance.

For a stereo pair, both speakers should be equidistant from the main listening position. A speaker 3 feet closer will sound significantly louder, creating an apparent imbalance. Adjust speaker positions so both are the same distance from where you sit.
Test each speaker solo.

In the Bose Music app, temporarily remove one speaker from the stereo pair and play audio through each speaker alone at the same volume. If one is noticeably louder at the same setting, there is a hardware difference between the two. If both sound equal solo, the issue is placement or assignment.
Rebalance using the Bose Music app equaliser.

Some Bose models offer an equaliser in the app. If minor placement differences cannot be corrected physically, reduce treble or overall level on the louder channel's EQ. This is a workaround — the proper fix is equal placement distance.

When to Call a Professional

If one speaker of a stereo pair is noticeably quieter even when tested solo at the same volume level, that speaker's driver may be damaged and need repair.