Frequency Sweep Test
A glide across the whole audible range with a live frequency readout — the fastest way to hunt rattles and dead zones.
20 Hz
ReadyDuration
Scale
Turn your system volume down first
Start at a low volume, especially with headphones and low bass tones, then raise it slowly.
Press Esc to stop all sound
This tool runs locally in your browser — no audio is uploaded.
How to use
- 1
Set the range and speed
Default is 20 Hz → 20 kHz over 20 seconds, logarithmic. Shorten to 10 s for a quick pass or extend to 60 s for careful listening; flip direction to sweep down.
- 2
Start low-volume and listen
Keep the volume at the default 30% for the first pass. Listen for buzzes, rattles, sudden drop-outs, or ranges that feel painfully sharp.
- 3
Zoom into problems
Note the frequency shown when something sounds wrong, then reproduce it exactly on the tone generator page to confirm and isolate it.
How it works & limits
The sweep is a single sine whose frequency ramps continuously via the Web Audio API. A logarithmic ramp spends equal time per octave, matching how hearing works and making the low end listenable; a linear ramp spends equal time per hertz, rushing past the lows and lingering in the highs. The readout shows the current frequency in real time.
Limits to keep in mind: what you hear is your whole chain — source, browser, DAC, amplifier, speakers, room, and ears. Drop-outs at the extremes are usually gear limits, not faults. At high volume, resonances can appear that vanish at normal levels; judge at your normal listening level.
FAQ
Logarithmic or linear sweep — which should I use?
Logarithmic by default: it covers the audible range the way we hear it, giving the bass proportionate time. Linear is useful when you specifically care about the high frequencies.
Why do I hear nothing at the start (or end) of the sweep?
The first seconds at 20–30 Hz are below what most systems reproduce, and the top end beyond your hearing limit is silent to you by definition. Both are normal.
Something rattles at a specific frequency — now what?
Read the frequency at that moment, open the tone generator, dial it in, and hold it while you press on nearby objects, grilles, and desk parts to find what resonates.
Is a sweep safe for my speakers?
At sensible volume, yes. Keep the slider at or below 30–40% for full-range sweeps; low frequencies at high level are the most demanding part for small drivers.
Can I sweep only the bass or only the treble?
Yes — set custom start and end values, for example 20–200 Hz for a bass sweep. The bass test page also has a guided descent mode.
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