The Bose QuietComfort Ultra Earbuds are tuned for a rich, warm sound with active noise cancelling and a spatial audio mode, and a sound that seems thin, muffled, harsh or lacking bass is usually down to the ear tips, the fit, the connection or the audio settings, rather than a fault in the drivers. The first and biggest factor is the seal. The earbuds come with several tip sizes and a stability band, and Bose's setup in its app has a fit test that checks that the seal is good.
The checks in more detail
Without a seal, bass vanishes and the noise cancelling fails, so try the other sizes of tip and push the buds in with a slight twist. A tip that is blocked with wax or debris muffles the sound; clean the nozzle with a soft dry brush. Then check the sound settings in the Bose Music app. The equaliser lets you adjust bass, mid and treble, and a changed setting can produce a strange sound, so reset it to flat. Immersion mode, or spatial audio, changes how the music sounds and may seem odd with some recordings, so switch it off to compare.
Noise cancelling modes, Quiet and Aware, affect the sound too; Aware lets outside sound in and can make music seem quieter. The earbuds adjust their sound to the fit with a feature that checks your ear, called CustomTune in Bose's line, and it can be redone from the app if the sound changes. Check the source and the codec. Streaming apps have quality settings: a low-quality or data-saver setting makes music sound flat, so choose the highest setting, and phone volume that is low with the earbuds high can add noise.
The earbuds support the common Bluetooth codecs, and an Android phone that supports aptX Adaptive may offer better quality when both agree. Update the earbuds' firmware in the app. Wireless interference causes crackle or dropouts, so move away from busy 2.4 GHz traffic. If one earbud sounds quieter, it may be blocked or have a poor seal. If every setting is right and the sound is still harsh on all sources, contact Bose with the serial number, since a faulty driver is covered by warranty.
Differential
Likely causes of “Bose QuietComfort Ultra Earbuds sounds distorted, muffled or unbalanced”, and how to tell them apart
- 1
A poor seal
What separates it Thin sound and weak bass
How to confirm Try other tip sizes and re-seat the buds
- 2
Blocked nozzles
What separates it Muffled sound
How to confirm Clean them with a soft dry brush
- 3
An equaliser or mode setting
What separates it Odd tone
How to confirm Reset the equaliser and switch immersion off
- 4
Low-quality streaming
What separates it Flat music
How to confirm Choose the highest quality in the streaming app
- 5
Interference or old firmware
What separates it Crackle or dropouts
How to confirm Move away and update the firmware
Before you touch a setting
Record this first — changing settings destroys the evidence
- The tip size in use
- Whether the fit test passes
- The equaliser and mode
- The streaming quality setting
Try in this order
0 of 6 completedRun the fit test
ReversibleIn the Bose Music app.
Try other tip sizes
ReversibleAnd seat the buds.
Clean the nozzles
ReversibleGently.
Reset the equaliser
ReversibleAnd try with immersion off.
Raise the streaming quality
ReversibleIn the app.
Update the firmware
ReversibleIn the Bose Music app.
Model-specific
What is true of this model and not of its siblings
- Seal
- Fit decides bass and noise cancelling.
- Modes
- Aware changes how music sounds.
Stop boundary
When this stops being a self-service repair
- !If the sound is harsh on every source after the checks, contact Bose with the serial number
- !Update the firmware first
- !Test on another phone
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is there no bass?+
The seal is poor.
Does the equaliser matter?+
A changed setting can make the sound odd.
Why does Aware mode sound quieter?+
It lets outside sound in.
Can firmware help?+
It can fix tuning issues.