A frequency sweep is a tone that moves smoothly from one frequency to another, for example from 20 Hz up to 20,000 Hz. Set the start, end and length, choose a logarithmic or linear sweep, and press Play. The current frequency is shown as it plays. Press I can't hear it when the tone disappears to mark that frequency, and download the sweep as a WAV file to use anywhere.
Logarithmic or linear?
A logarithmic (exponential) sweep spends the same time on every octave: 20–40 Hz takes as long as 10–20 kHz. That matches how we hear pitch, and it is the usual choice for testing audio equipment. A linear sweep moves the same number of hertz each second, so in a 20 Hz–20 kHz sweep it spends most of its time above 2 kHz and races through the bass. Linear sweeps suit narrow ranges and science demonstrations.
What sweeps are good for
- Finding your speakers' range: sweep up from 20 Hz and note where the bass becomes audible; sweep up to 20 kHz and note where the treble fades.
- Finding rattles and buzzes: a slow sweep (60 seconds or more) through the bass makes loose panels, grilles and objects in the room buzz at their own frequencies.
- Room resonances: some bass notes boom and others vanish depending on where you sit. A slow low sweep shows where.
- Checking the limits of your hearing on this device: sweep up and press I can't hear it. The result depends on your headphones and volume as well as your ears, so it is not a hearing test. If you are worried about your hearing, see an audiologist.
Up and down, and loops
Loop repeats the sweep from the start. Up and down sweeps up then back down without a jump, which is easier on the ears and on speakers. Both keep going until you press Stop.
Downloading a sweep
A single sweep downloads at exactly its set length. Looped sweeps use the length in the WAV box. Files are 16-bit stereo at 44.1 or 48 kHz, and the sweep fades in and out over 10 ms so it starts and stops without a click. For ready-made multichannel files, see our test files.
Limits
The highest frequency a browser can play is half its sample rate: 22,050 Hz at 44.1 kHz or 24,000 Hz at 48 kHz. Start your device volume low; sweeps pass through the frequencies where both ears and small speakers are most sensitive. For single steady tones, use the tone generator.
Common questions
What is a frequency sweep?
A tone that changes smoothly from one frequency to another, such as 20 Hz to 20,000 Hz. It is used to test speakers, find rattles and check frequency range.
Should I use a log or linear sweep?
Logarithmic for audio testing, because it spends equal time on each octave the way we hear. Linear for narrow ranges or demonstrations.
How long should a sweep be?
15–30 seconds for a quick check. 60 seconds or more through the bass when you are hunting for rattles or room resonances.
Can I download a 20 Hz to 20 kHz sweep?
Yes. Set it up (or press the 20 Hz–20 kHz preset) and press Download WAV. You get a 16-bit stereo WAV at 44.1 or 48 kHz.
Is this a hearing test?
No. Where the sweep fades depends on your headphones and volume as well as your ears. See an audiologist for a hearing test.
Last reviewed 14 November 2026 by Sri Murugan Systems. Found a mistake? Tell us.