With the Bose QuietComfort Earbuds II, a one-sided sound has a handful of causes that differ a little from other Bose earbuds, because these were the first to tune themselves to your ear. Begin with the simple fact of power: each earbud has its own battery, and one that is empty or was seated crookedly in the case will not play. Take both out, check that each shows a light or is announced by the voice prompt, and look in the Bose Music app for the two battery levels.
The checks in more detail
If one is low, charge both for half an hour with the lid closed. The charging contacts are tiny dots, and skin oil or wax on them stops charging, so wipe them with a dry cotton swab. The second cause is the tip and the stability band. Because the sound and the cancelling are tuned to your ear canal, a tip that is the wrong size for one ear lets sound leak out and makes that side seem quiet.
Run the fit test in the app and try different tips, since many people need a different size in each ear. A band that is pressed against the ear fold can tilt the earbud away from the canal. Seat each bud with a slight twist forward. Check also that a clogged nozzle is not the issue; a soft, dry brush clears wax from the mesh. Phone settings cause some cases. The balance control in the accessibility menu can shift the sound to one side, and mono audio, if on, mixes the channels; look at both and reset them.
If the problem is only in one app, the app may be sending a single channel, so test with music. To rebuild the link between the buds, put both in the case, forget the earbuds on the phone and pair again; the Bose Music app offers an earbud reset in its settings for stubborn faults, which removes all pairings. Update the firmware. If one bud is silent on all devices after these steps, it has a hardware fault, and Bose will repair or replace it under warranty with the serial number.
Differential
Likely causes of “Bose QuietComfort Earbuds II plays from only one side or channel”, and how to tell them apart
- 1
One bud empty or seated badly in the case
What separates it One side is silent
How to confirm Charge both and clean the contacts
- 2
A tip of the wrong size in one ear
What separates it One ear sounds thin
How to confirm Try other tips in the fit test
- 3
A band pressed against the ear
What separates it The bud tilts away
How to confirm Reseat with a slight twist
- 4
A balance or mono setting on the phone
What separates it The sound favors one side
How to confirm Reset them in accessibility
- 5
A hardware fault
What separates it One bud is silent everywhere
How to confirm Warranty repair
Before you touch a setting
Record this first — changing settings destroys the evidence
- The battery of each bud
- Which tips are fitted
- The balance setting
- Whether it happens on another device
Try in this order
0 of 6 completedCheck each bud's charge
ReversibleIn the app.
Wipe the charging contacts
ReversibleWith a dry swab.
Run the fit test
ReversibleTry other tips.
Reset balance and mono
ReversibleIn accessibility.
Pair again
ReversibleOr reset the earbuds.
Contact Bose
ReversibleIf a bud stays silent.
Model-specific
What is true of this model and not of its siblings
- Tuned to the ear
- The fit sets both sound and cancelling.
- Two batteries
- Each bud has its own.
Stop boundary
When this stops being a self-service repair
- !If one bud is silent on every device after a reset, contact Bose with the serial number
- !Update the firmware
- !Test on a second phone
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does one QC Earbuds II bud play quietly?+
A poor seal or a low charge.
Can the phone cause it?+
Balance or mono settings can.
Do I need different tips?+
Often, one per ear.