Check left and right channels, bass, a 20 Hz to 20 kHz sweep, high frequencies and speaker wiring polarity
How to use
Set the volume low, then press Left, Both and Right. Each sound should come only from that side.
Play the frequency sweep and press Stop when you can no longer hear the tone.
Try the bass tones to see how deep your speakers or headphones go, and the high tones for the top end.
For a stereo speaker pair, compare In phase and Out of phase to check the wiring.
Why use this tool
Left and right, clearly: Soft noise bursts from each side make swapped channels or a dead earbud obvious in a second.
Full range sweep: A smooth logarithmic sweep from 20 Hz to 20 kHz with the frequency shown live, so you can see where the sound fades out.
Bass and treble tones: Fixed tones from 20 Hz to 150 Hz and from 8 kHz to 20 kHz show the real range of your speakers or headphones.
Wiring polarity check: In-phase and out-of-phase noise reveals a speaker with its plus and minus wires swapped, which quietly ruins bass and stereo.
Nothing to download: Every sound is generated live in your browser, instantly, and it works offline.
Frequently asked questions
How do I test left and right audio?
Press Left, then Right. The sound should come only from the matching side. If Left plays on the right, your headphones are on backwards or the channels are swapped in your audio settings or cables.
Why can't I hear the lowest bass tones?
Small speakers physically cannot move enough air for deep bass. Laptop and phone speakers usually fade below about 100 to 150 Hz. Good headphones, bookshelf speakers and subwoofers go lower.
What is the highest frequency people can hear?
Young people can often hear up to about 20 kHz, and the upper limit falls with age, commonly to around 15 kHz by middle age. Many speakers and headphones also stop around 15 to 16 kHz, so the limit you find may be the equipment's.
What does the polarity test show?
If both speakers are wired the same way, In phase sounds centred and full. If one speaker's wires are reversed, the speakers cancel each other and In phase sounds thin and hollow, while Out of phase sounds normal.
Is it safe for my speakers and ears?
At sensible volumes, yes. Start low, especially with headphones, because very high and very low tones can be louder than they seem. Stop if anything sounds distorted.