Quick answer
Each test sound should come only from its own side. If the left sound plays on the right, your speakers or headphones are swapped; if a side stays silent, that channel is faulty.
How to use the Left/Right Speaker Test
- Lower your system volume, then click Left. You should hear chimes only from the left speaker or left ear cup.
- Click Right. The sound should come only from the right side. Both should sound centered.
- Click Stereo sweep. The sound should travel smoothly from left to right and back.
- Use the frequency test to play a steady tone. Move the slider down to check bass and up to check treble.
Example
In a game, footsteps you hear on the left seem to come from the right. You click Left and the sound comes out of your right ear cup: your headphones are on backwards, or left and right are swapped in your sound settings. If you only hear sound on one side for both buttons, the cable or one driver is probably damaged.
How it works
The test generates sound directly in your browser with the Web Audio API, so it doesn't need to download audio files. A stereo panner sends the signal to the left channel, the right channel or both. The stereo sweep moves the sound gradually between the two channels.
The frequency test produces a pure sine wave. The slider is logarithmic, which matches how we hear pitch: each step of the same length is the same musical interval.
| Range | Frequencies | Examples |
|---|---|---|
| Sub-bass | 20-60 Hz | Rumble, kick drum body |
| Bass | 60-250 Hz | Bass guitar, male voice fundamentals |
| Midrange | 250 Hz-4 kHz | Voices, most instruments |
| Treble | 4-20 kHz | Cymbals, “s” sounds, air |
Small laptop speakers often can't reproduce tones below 100-150 Hz. That's a physical limit, not a fault.
Speaker and headphone checks worth knowing
- Test one change at a time: if one side is silent, try another cable or device first. If the fault moves with the headphones, they're the problem; if it stays, it's the computer or its settings.
- Bass sounds weak: play 50 Hz and 100 Hz. Laptop and phone speakers usually can't produce anything below about 150 Hz, while good headphones play 50 Hz clearly.
- Rattling at one frequency: sweep the frequency slider slowly. A buzz at one spot usually means something loose near the speaker, not a broken speaker.
- Sound seems to come from inside your head: that's normal for headphones when both channels play the same sound. Speakers create the sound in front of you instead.
- Accessibility setting: if you hear both channels on one side, check that “Mono audio” is turned off in your system's accessibility settings.
Frequently asked questions
I only hear sound from one side. What should I check?
Check the balance slider in your system sound settings, plug the cable in fully, try another device to see if the fault moves with the headphones, and turn off any “mono audio” accessibility setting.
Left and right are swapped. How do I fix it?
For headphones, make sure you're wearing them the right way round (look for L and R marks). For speakers, swap the cables. Some sound drivers also have a channel swap option.
Why can't I hear the 15 kHz tone?
Hearing above 15 kHz naturally declines with age, and many small speakers can't reproduce it. This is normal.
Can loud test tones damage my speakers?
Long, loud tones at very low or very high frequencies can damage small speakers and are uncomfortable to hear. Keep the volume moderate and play tones briefly.
Does this test Bluetooth headphones?
Yes. Any audio output your system uses works: Bluetooth, USB, HDMI, built-in speakers and wired headphones.