Earbud left right test — when only one side plays
When one side is quiet, or the channels feel swapped. Drive each side and hear the answer.
When one earbud is silent or quieter than the other. Drive each channel separately to tell an earphone fault from a device setting, and check the frequency range you can actually hear.
Turn the volume down first — test tones are louder than music at the same setting.
Which side is actually at fault
Press Left and Right alternately to establish which channel is affected. If one side produces no tone at all, the driver has failed or a contact is broken. On wireless earbuds, put both back in the case, take them out again and let them re-pair before concluding anything — one bud dropping its connection is usually corrupted pairing data rather than a dead unit.
If the channels sound swapped
If pressing Left produces sound on your right, the earphones are not the problem — the playback device's channel configuration or the cable is. Run the same test on a second device and the answer separates immediately.
What the sweep can and cannot tell you
Human hearing normally spans 20Hz to 20kHz, and the top end recedes with age: 16kHz is a common ceiling in your thirties, around 14kHz in your forties. So treat the high end as a hearing check rather than an equipment check. A phone's built-in speaker also cannot reproduce below roughly 200Hz, so silence at the bottom of the sweep through a speaker is expected, not a fault.
When you hear noise mixed in
Crackle confined to a particular band means driver damage. Noise spread evenly across the whole range points at the connection first — Bluetooth interference, or a dirty cable contact.
Check the device's balance slider before blaming the earbuds
When one side is quieter, the earphones get the blame, but the playback device's accessibility settings are a frequent cause. iPhone keeps a left/right slider under Settings → Accessibility → Audio & Visual; Android under Settings → Accessibility; Windows in the sound device properties. It gets nudged in a pocket, or set once and forgotten. If both channels sound equal in this tool but music is lopsided, the slider or the recording is the problem.
The wrong ear tip costs you the bass first
Most complaints that in-ear headphones sound "thin" come down to ear tip size. Any gap between the tip and your ear canal lets low frequencies escape first, leaving the treble exposed and sounding harsh. If the low end of the sweep is unusually quiet, move up one tip size and measure again. This is the single biggest reason two people review the same earbuds completely differently.
A gap in the sweep — where it sits tells you the cause
Nothing below 200Hz is usually the playback device; phone speakers simply do not reproduce that range. Nothing above 14kHz is more likely your hearing than the hardware, for the age reasons above. A dropout in the middle of the range is the one that means driver damage.
How to test properly
- Lower the volume first. Test tones are louder than music at the same setting, and high-frequency sweeps are hard on your ears
- Test wired before Bluetooth where you can — it removes the connection as a variable
- Swap the buds between ears and repeat. If the symptom follows the unit it is the hardware; if it stays with the ear it is not
- Turn any equaliser off. An app EQ measures a band that is already being suppressed
Frequently asked
One side is quieter. Are the earbuds broken?
Swap them between ears first. If the symptom follows the unit, the earbud is at fault; if it stays with the ear, the playback device is. In the second case the accessibility left/right balance slider has most likely been nudged to one side.
I cannot hear the high tones. Is that the earbuds?
Losing everything above 14kHz is more likely your hearing than the hardware. The top end recedes with age — 16kHz is a common ceiling in your thirties and around 14kHz in your forties. A dropout in the middle of the range is the one that indicates driver damage.
There is no bass at all.
If you are listening through a phone speaker, that is normal — most cannot reproduce below about 200Hz. If bass is weak through earphones, the ear tip probably does not seal, letting the low end escape. Move up one tip size and measure again.