Left, right: are your speakers wired correctly?
Test your speakers and headphones: left and right channels, 20 Hz–20 kHz frequency sweep, test tones and audio output selection.
Left and right channels
Each button plays a short tune on the chosen channel. Check it comes out of the right side.
Frequencies
Note the frequency at which you stop hearing anything during the sweep: that is the limit of your equipment… or your ears.
Settings
⚠ Start with a low volume, especially with headphones.
FAQ
Sound comes from the wrong side, what should I do?
Swap the speaker cables or check your headphones (L = left, R = right). On Windows, also check the “mono audio” option in Accessibility, which mixes both channels.
Up to what frequency should I hear?
Young ears hear from 20 Hz to about 18–20 kHz; with age the upper limit often drops to 12–15 kHz. Small speakers reproduce bass below 100 Hz poorly.
Why can’t I choose the audio output?
Choosing the output is only available in Chrome and Edge. In other browsers, sound plays through the system default device.