Frequency Sweep Generator
Glide from a low to a high frequency over the time you choose, for testing speakers, headphones and rooms.
Protect your hearing
A logarithmic sweep spends the same time on every octave, which suits hearing and room measurements. A linear sweep adds the same number of hertz every second.
Halfway through (10 s) the tone is at 632.5 Hz.
The highest point of the wave, relative to digital full scale.
Up to 12 hours. Long files are written in pieces, so length costs time, not memory.
Fades start and end the file smoothly, so it does not click. Keep at least a few milliseconds.
How it works
- Set the start and end frequencies and choose linear or logarithmic.
- Set the duration and a safe level.
- Press Play, or create a file to download.
What it does
A sweep is a sine tone that glides from a start frequency to an end frequency over the time you set. Use it to listen for resonances in a room, to check where a speaker or headphone stops reproducing bass or treble, or to feed a measurement. The tool plays it live and exports it as a file.
Linear or logarithmic
A logarithmic sweep spends the same time on every octave, so 20 to 40 Hz takes as long as 10 to 20 kHz. This matches how hearing works and is the usual choice for audio tests. A linear sweep adds the same number of hertz each second, so most of it is spent at high frequencies.
The page shows the frequency at the halfway point of your settings, so you can check the curve. The phase is continuous, which means there are no clicks within the sweep.
Using a sweep safely
The level starts at −18 dBFS. Low frequencies can move a small speaker cone further than it can take, and high frequencies are tiring even when they seem quiet, so start with the device volume low and raise it slowly. A descending sweep (start higher than end) works too.
A sweep alone does not measure a room. To measure, record it with a microphone and look at the recording in a spectrum or spectrogram tool.
Questions
What sweep should I use to test headphones?
A logarithmic sweep from 20 Hz to 20 kHz over 20 to 30 seconds, at a low level. Listen for dropouts, rattles and where the sound fades at either end.
Why is the end of the sweep silent for me?
Most adults cannot hear above 16 to 18 kHz, and many speakers and headphones do not play the lowest octaves. Silence at the ends is normal.
Does the exported file match what I heard?
Yes, within the limits of the sample rate. The export is calculated, not recorded. Frequencies must be below half the sample rate, and the page says so if they are not.