Speaker test
Click a frequency to play a tone. If you hear it, that range works.
Tone generator
30%
Playing: --
Stereo channels
Frequency sweep
Why can't I hear low frequencies?
Small speakers (laptop, phone) physically can't reproduce anything below 100-200 Hz. That's hardware, not a bug. Use headphones or external speakers with a subwoofer to test bass.
Can this damage my speakers?
No. Tones are generated at safe amplitudes. Start with volume low and increase gradually, especially with headphones.
What's the frequency sweep for?
It moves through 20 Hz to 20 kHz over 10 seconds. You'll hear where your speakers start reproducing sound and where they drop off. Gaps or buzzing at specific frequencies indicate driver problems or resonances.
How do I know if left/right channels are correct?
Click Left Channel - you should hear sound from the left side only. Click Right Channel - right side only. If both sides play or the sides are swapped, check your cable or audio settings.