Headphone Check20 Hz – 20 kHz
Frequency Sweep Test
One tone glides from the deepest bass to the highest treble. On good headphones it rises smoothly at an even loudness; dips, peaks, rattles and the point where it vanishes tell you how your headphones (and your ears) handle the full range.
Set the volume to about 40% before you start: the middle of the sweep is the loudest part.
Single tones
Tone generator
High tones can be sharp. Never use full volume.
How to run a frequency sweep
Start quiet
Human hearing is most sensitive between 2 and 5 kHz, so a sweep that sounds soft at 50 Hz can feel loud in the middle. Start at about 40% volume.
Play the full sweep and just listen
Do not chase numbers on the first run. Notice whether the tone stays even, where it gets suddenly louder or quieter, and whether anything rattles.
Find the edges
Use the bass sweep for the bottom and the high sweep for the top. Press Stop the moment the high tone disappears: the page shows the frequency where you stopped.
Compare your ears
Listen with one earcup lifted, then the other. Both sides should behave the same.
What the results mean
| You notice | Likely reason |
|---|---|
| Loudness rises and falls a little along the way | Normal. No headphone is perfectly flat, and the ear itself is uneven. Small bumps are part of each model's "sound signature". |
| A sharp, piercing spot around 5–10 kHz | A treble peak. Common, and the cause of "fatiguing" headphones. An equaliser cut of a few dB at that frequency helps. |
| A tone that drops out in one ear only | A driver or fit issue on that side. Re-seat the earbud, clean the mesh, and compare with the left right test. |
| Rattle or buzz at a single pitch | A loose or damaged part resonating. Find it precisely with the bass test or the tone generator. |
| Nothing above 15–17 kHz | Very common, from two sources: the Bluetooth connection and your ears (see below). |
Why the top of the sweep fades out
Two things set the upper limit you hear. The first is the connection. Wired headphones and good USB DACs pass everything up to 20 kHz. Bluetooth codecs compress the signal, and many encoders cut the very top end, often somewhere between 15 and 20 kHz depending on the codec, the bitrate and the signal strength. If the sweep fades earlier on Bluetooth than on a cable, that is the codec, not the headphones.
The second is hearing. The textbook range of 20 Hz to 20 kHz applies to young ears; the upper limit falls gradually with age, and many adults stop hearing tones somewhere between 14 and 17 kHz. This test is not a hearing test and cannot tell you anything medical. If you notice a sudden change, ringing, or a clear difference between your ears that the headphones do not explain, see a doctor or audiologist.
What is an Hz test?
"Hz test" usually means playing single test tones at known frequencies, which is what the single tone buttons and the generator slider do. Hertz (Hz) is the number of vibrations per second: 50 Hz is a deep hum, 440 Hz is the A that orchestras tune to, 1 kHz (1,000 Hz) is the classic reference tone, and 15 kHz is a thin, high whistle. Use single tones to check one frequency on both sides, to find the exact pitch of a rattle, or to compare two pairs of headphones at the same point.
Frequently asked questions
What is a frequency sweep?
A sine tone whose pitch changes continuously from low to high. This one rises logarithmically, so each octave takes the same time, which matches how we hear pitch.
What frequency range should headphones have?
Spec sheets usually say 20 Hz to 20 kHz or wider. That number says little on its own; what matters is how evenly they play inside the range, which is exactly what a sweep lets you hear.
Why does 1 kHz sound louder than 100 Hz at the same volume?
The ear is far more sensitive in the middle frequencies than at the extremes. It is normal for low and very high tones to sound quieter.
Can my browser play 20 kHz?
Yes. Browsers usually run audio at 44.1 or 48 kHz, which can reproduce tones up to just above 20 kHz. Whether you hear them depends on your headphones, the connection and your ears.