Frequency sweep generator
Glide from one frequency to another — linear or logarithmic, once or looped.
— Hz
Sweep shape
Repeat mode
Waveform
Stopped
What a frequency sweep is
A frequency sweep is a tone that glides continuously from a start pitch to an end pitch instead of holding one note. This frequency sweep generator moves between any two frequencies you enter — upward for a rising test, downward for a falling one — over a duration from 1 to 120 seconds. A live readout shows the exact current frequency as the glide passes through it.
Sweeps reveal problems that static tones miss. A slow glide across the full range exposes rattles at specific cabinet resonances, sudden dips where a room mode cancels the sound, and the point where small speakers simply give up on bass. One smooth pass tells you more about a speaker than a dozen isolated test tones.
Linear vs logarithmic sweeps
The shape setting controls how the glide spends its time. A linear sweep moves in equal hertz steps, so it races through the bass and lingers in the treble — useful when you want to inspect high frequencies closely. A logarithmic sweep moves in equal musical steps, spending the same time on each octave, which matches how hearing works and is the better default for full-range checks.
Repeat modes change how the pass behaves at the end. Once stops at the target, loop jumps back to the start for repeated passes, and ping-pong glides back down again so you can compare the rising and falling impressions of the same resonance.
| Goal | Shape | Mode |
|---|---|---|
| Full speaker check, 40 Hz to 15 kHz | Logarithmic, 20–30 seconds | Once |
| Hunting a cabinet rattle | Logarithmic, 60+ seconds | Ping-pong |
| Comparing two headphones | Logarithmic, same duration | Loop |
| Inspecting treble detail | Linear, 15–20 seconds | Once |
How to run a clean sweep test
Set the room up before you press start: close the test to background noise, place the speaker or wear the headphones as normal, and pick a comfortable level with a static tone first. Sweep levels feel like they change as the glide moves — bass sounds quiet, upper mids sound loud — so resist the urge to adjust mid-pass.
Listen for three things: buzzing that appears at one spot and vanishes (a resonance), sections that dip much quieter (cancellation or driver limits), and differences between the left and right sides when you repeat the pass panned to each side. Note the readout frequency at each event; that number is the actual diagnostic result.
Sweep ideas beyond speakers
Rooms deserve sweeps as much as drivers do. A slow logarithmic glide from 40 Hz upward maps room modes directly: the spots that boom mark resonances your furniture placement can tame, and the spots that vanish mark cancellations worth knowing about before you position a desk or a mixing chair.
Hearing sketches benefit too. Run the same sweep monthly at a fixed comfortable level and note the highest frequency you still detect; the trend over time is more informative than any single session. Treat every such sketch as casual self-screening — interesting, motivating, but never a diagnosis — and confirm anything surprising on better equipment before drawing conclusions.
Teachers find sweeps the single most persuasive acoustics demo available: one glide shows the class that pitch is continuous, that hearing has edges, and that every room colors sound. Pair the pass with the Hz chart afterward so students can attach numbers to what they just heard.
Frequently asked questions
What is a frequency sweep generator used for?
A frequency sweep generator tests how speakers, headphones, and rooms respond across a range of pitches in one smooth pass. It finds rattles, dropouts, and resonances faster than stepping through static tones one by one, and shows the exact frequency of each issue on the live readout.
Should I use a linear or logarithmic sweep?
Use logarithmic for most checks: it spends equal time on each octave, matching how you hear pitch, so bass and treble get fair coverage. Use linear when you want to inspect the treble region closely, since a linear glide naturally lingers at high frequencies.
What do loop and ping-pong modes do?
Once plays the glide a single time and stops. Loop restarts from the beginning for repeated identical passes, which helps when comparing two devices. Ping-pong glides back down after reaching the top, letting you hear each resonance rising and falling.
Why does the sweep sound louder in the middle?
Human hearing is most sensitive between roughly 2 kHz and 5 kHz, so a constant-level sweep sounds louder there and quieter in the deep bass. That is normal perception, not a fault in the sweep — judge problems by sudden changes, not by the overall loudness curve.