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How to play a test tone to check speakers and headphones

You want to check that both speakers work, find a rattle, tune to A4 or see how high you can hear. You will play a sine tone, change its frequency and send it to one side at a time. The sound is made in your browser; nothing is uploaded.

5-minute read

Today's result A steady tone at the frequency you choose, on the left, right or both speakers, with its nearest musical note.

Turn the device volume down before you press Play, especially with headphones. High tones can be unpleasant even when quiet.

Open Tone generator
Contents

  1. Know frequency and hearing range

    Frequency is vibrations per second, in hertz (Hz). People hear roughly 20 Hz to 20 kHz; the top end falls with age, often to 15–17 kHz for adults. 440 Hz is the note A4.

    20 Hz ← hearing range → 20 kHz · A4 = 440 Hz.
    20 Hz ← hearing range → 20 kHz · A4 = 440 Hz.

  2. Open Tone generator on cv.cm

    It is set to 440 Hz, a sine wave, both speakers and 20% volume. Press Play and raise the volume slowly; press Stop to end it.

    Open Tone generator

  3. Set the frequency

    Type a value, drag the slider, use −1/+1 for small steps or ÷2/×2 to move an octave. Presets give 440 Hz, middle C, 1000 Hz and more.

  4. Test left and right

    Under Speaker pick Left, then Right. Each side should play alone; if both play, check that the speakers are not set to mono.

    Left only · both · right only.
    Left only · both · right only.

  5. Sweep for rattles and limits

    Slowly move the slider from 50 Hz up. A buzz at one frequency points to a loose part; where a tone fades out is your speaker's (or hearing's) limit.

  6. Try other waveforms

    Square, triangle and sawtooth add harmonics and sound buzzier. Use sine for measurements and the others to hear the difference.

Use with these tools

FAQ

What frequency should I use to test speakers?

Start with 440 Hz or 1000 Hz for level, then sweep from 50 Hz to 15 kHz.

How do I test left and right channels?

Pick Left or Right under Speaker and check that only that side plays.

Why can't I hear 18 kHz?

Hearing above 15–17 kHz fades with age, and many speakers cannot play it.

Can a tone damage my speakers?

At low volume, no. Very loud low or high tones can harm small speakers and your ears.

Is the tone generator free?

Yes. It runs in your browser with no sign-up.