Generator · 1 Hz – 20 kHz sweep
Frequency Sweep Generator
Sweep smoothly between any two frequencies, linearly or logarithmically, over 0.5 to 120 seconds. Set separate start and end levels, hold the final tone, or loop the whole thing. The sweep is synthesised live in your browser and can be saved as a WAV file.
A full-range sweep at a high level can damage tweeters, and sub-bass content needs speakers that can actually reproduce it. Start at a low level, sweep only the range you need, and be ready to stop. The limiter prevents digital clipping, not loud playback.
Linear moves by the same number of hertz each second; exponential moves by the same number of octaves, so it sounds even from bottom to top.
Ready. Press play to run the sweep.
Watch the spectrum peak travel left to right as the sweep runs. Sub-bass content (20–60 Hz) is only audible on speakers that can reproduce it - headphones and small laptop speakers will roll it off.
| Use | Range | What to look for |
|---|---|---|
| Driver break-in | 20 Hz → 20 kHz | Loosen a new driver’s suspension. Keep the level low; a full-range sweep at high level can damage tweeters. |
| Room-mode hunting | 20 → 300 Hz, slow | Sweep the bass and listen for the frequencies that boom or null - those are the room’s standing waves. |
| Speaker crossover check | 1 k → 20 kHz | Listen for a dip or a dropout where the tweeter takes over. A broken crossover shows up as a gap during the sweep. |
| Calibration / EQ | 20 → 20 kHz, log | Feed a log sweep into a measurement mic, record it, and deconvolve to get the impulse response and frequency response. |
| Tweeter and hearing limits | 10 k → 20 kHz | Find the top of what you or a transducer can reproduce. Most adults stop hearing near 15–17 kHz. |
In a linear sweep the frequency is f(t) = f₀ + (f₁ − f₀)·t / T: every second adds the same number
of hertz. In an exponential (logarithmic) sweep it is
f(t) = f₀ · (f₁ / f₀)t / T
so the frequency climbs by the same factor in every equal slice of time. Taking the log base two, the
total span is log₂(f₁ / f₀) octaves and the sweep rate is
R = log₂(f₁ / f₀) / T octaves per second
A 20 Hz → 20 kHz sweep covers log₂(1000) ≈ 9.97 octaves; over 10 seconds that is about one octave
per second. Because the sweep passes through every octave for the same length of time, it carries equal energy
per octave, which is exactly what makes it the standard signal for room and speaker measurement.
Why does an exponential sweep sound even while a linear one does not?
We hear pitch in ratios, not absolute hertz. A linear sweep from 100 Hz to 200 Hz spends as much time in that octave as it does going from 10 kHz to 20 kHz - an octave you can barely notice. An exponential (logarithmic) sweep covers the same number of octaves in every second, so it sounds like a smooth, even glide from bottom to top. For measurements, the log sweep is also the one you deconvolve.
Can a sweep damage my speakers?
A full-range sweep at a high level absolutely can. A tweeter has a few watts of thermal rating, and the highest octave of a sweep passes through it in a fraction of a second, so the level slider matters more than it does for a single steady tone. Start at a low level, sweep the range you care about rather than always 20 Hz–20 kHz, and never leave a sub-bass sweep running at full level - small speakers cannot reproduce 20 Hz and will just distort.
What does “hold the final tone” do?
With it on, the sweep runs to the end frequency and then keeps sounding that tone until you press Stop. It is useful for checking a crossover point or a single frequency you want to stay on. With it off, the output goes silent the moment the sweep finishes.
Is the saved WAV exactly what I heard?
Yes. Save WAV renders the same start/end frequencies, duration, waveform, ramp and level curve offline in your browser and downloads a 16-bit PCM file at 44.1 kHz - the whole sweep, with a short fade at the start so the file does not click. It works in any audio editor or measurement tool.
Online Tone Generator
Pure sine, square, sawtooth and triangle tones from 1 Hz to 20 kHz, with precise frequency entry and WAV export.
Multiple Tone Generator
Run up to eight independent oscillators with per-voice frequency, waveform, level and stereo pan.
Noise Generator
White, pink and brown noise with band shaping - for masking, calibrating and testing.
Online Hearing Test
Step through audiometric frequencies from 125 Hz to 20 kHz and log what you can hear.
Subwoofer Test Tones
Low-frequency test signals from 16 Hz up, plus sweep tools for finding room and driver limits.
Acoustic Theory
The maths behind the tones: sine waves, harmonics, decibels, wavelengths and sample rates.