Test your bass, all the way down.
Play pure low-frequency tones, sweep from 150 Hz down to 10 Hz, and find the exact point your speakers or subwoofer give up. It'll tell you whether you've got true sub-bass or just polite mid-bass — plus a rattle test to hunt down buzzes. Runs in your browser; start the volume low, because deep bass can strain small speakers.
Press start, then hit "Mark my limit" the moment the tone fades to silence.
Bass & subwoofer test.
Watch the readout, feel for the floor. The sweep glides down until your system runs out of bass.
Protect your speakers
Sustained loud sub-bass is the fastest way to damage small speakers and drivers — you can bottom out a woofer or fry a tweeter's crossover before it even sounds loud. Start at about 30% volume and raise it gradually. If you hear hard buzzing, cracking, or a "chuffing" sound, back off immediately: that's the driver hitting its mechanical limit, not the music.
Before you start
- Start the volume lowSet volume to around 30% before playing anything. Deep bass carries far more power than it seems, and small speakers can be damaged before it even sounds loud.
- Know your gear's limitsA phone or laptop physically can't produce 30 Hz. If low tones are silent on tiny speakers, that's expected — test on the system you actually care about.
- Feel as well as listenBelow ~30 Hz you feel bass more than you hear it. Rest a hand on the speaker or subwoofer cabinet, or notice pressure in the room, not just sound.
- Mind the roomBass is shaped hugely by room modes and speaker placement. A tone that vanishes in one spot can boom in another — move around before blaming the gear.
How to test your bass
- 1Play a few tones. Tap the low-frequency buttons — start high at 100 Hz, then work down. Each toggles a pure sine; the readout names the band and what you should hear or feel.
- 2Run the descending sweep. Press Start sweep (or Space). The tone glides from 150 Hz down toward 10 Hz while the big readout counts down the frequency.
- 3Mark your limit. The instant the tone fades to silence, hit Mark my limit. That frequency is your system's low-end rolloff — the tool rates it and tells you what to expect.
- 4Hunt for rattles. Run the 40 Hz rattle test to send short bursts that shake loose buzzes from cabinets, desks, and panels. Then fine-tune any frequency with the slider.
Why you feel sub-bass more than you hear it
Low frequencies are long waves: a 30 Hz tone is about 11 metres from crest to crest, versus 17 cm for a 2 kHz note. Moving that much air takes a big driver with lots of excursion (in-and-out travel), which is why real bass needs physical size — a subwoofer or a large woofer. A phone speaker a couple of centimetres across simply can't displace enough air to reproduce 30 Hz at any meaningful level, so it fakes the low end or drops it entirely.
Your ears are also far less sensitive down low: the equal-loudness contours mean a 30 Hz tone has to be dramatically louder than a 1 kHz tone to seem equally loud. Below roughly 20 Hz you cross into infrasound, where perception becomes mostly tactile — pressure and vibration rather than pitch. That's why cinemas and clubs use dedicated subwoofers: to deliver the felt, physical impact of explosions and bass drops that ordinary speakers, and your ears, can't get from sound alone.
When to run a bass test
New subwoofer or speakers
Fresh out of the box, confirm how low it really reaches. Marketing says "20 Hz"; the sweep tells you where it actually rolls off in your room.
Setting subwoofer level
Dial in the crossover and gain by ear. Play tones around the crossover point and listen for a smooth handoff between sub and speakers, with no gap or bloat.
Chasing a rattle
A buzz on bass-heavy tracks is usually a loose panel, a desk object, or a cabinet screw — not the speaker. The rattle test finds the exact frequency that excites it.
Comparing headphones
Sweep two pairs back to back to hear which actually extends into the sub-bass and which just boosts mid-bass to feel "bassy."
Car audio
Cabins reinforce low bass, so a car sub can reach lower than the same driver indoors. Sweep to find where the system and the cabin combine — and where it distorts.
Room placement
Play a steady 40–50 Hz tone and walk the room: you'll hear bass swell and cancel as you move. It's the quickest way to find where a sub or a listening seat should go.
What your bass test is really telling you
Low-end results get misread constantly. Here's how to read the common ones:
My laptop can't play 30 Hz — is it broken?
No. Small drivers physically cannot move enough air for deep bass; there's nothing to fix. Silence below ~100–150 Hz on a laptop or phone is completely normal.
→ Judge bass on real speakers or a subwoofer. Treat tiny speakers rolling off early as expected behaviour, not a fault.
Something buzzes on low notes
Almost always a sympathetic rattle — a loose grille, a cabinet screw, a wall panel, or an object on the desk resonating at that frequency — not the driver failing.
→ Run the rattle test, then track the buzz by touch: press panels and remove nearby objects until it stops.
The bass vanishes in one spot
Room modes. Bass waves reflect and cancel at specific room positions, creating nulls where a tone nearly disappears and peaks where it booms.
→ Move your seat or the subwoofer. The "subwoofer crawl" — putting the sub at your seat and crawling the room to hear where it sounds best — nails placement.
It's loud but distorted down low
The driver is hitting its mechanical limit (bottoming out) or the amp is clipping. That hard buzzing or chuffing is the speaker straining, and sustained it will cause damage.
→ Turn the volume down. If distortion starts at the same level every time, that level is your system's honest ceiling — respect it.
Bass test glossary
- Hertz (Hz)
- Cycles per second — the unit of frequency. Lower Hz means lower pitch; 20 Hz is about the bottom of human hearing.
- Sub-bass
- The lowest bass, roughly 20–60 Hz — the felt, room-shaking foundation you sense as much as hear.
- Crossover
- The frequency where sound is split between the subwoofer and the main speakers. Set it where the speakers naturally roll off, often 60–80 Hz.
- Rolloff
- The frequency below which a speaker's output drops away. Your "low-end limit" is essentially where the rolloff makes the tone inaudible.
- Excursion
- How far a driver's cone travels in and out. Deep bass demands large excursion, which is why big drivers reach lower than small ones.
- LFE
- Low-Frequency Effects — the dedicated ".1" bass channel in 5.1/7.1 surround, sent to the subwoofer for rumble and impact.
- Port tuning
- The frequency a ported speaker's air vent is tuned to reinforce. Below it, output falls off fast and the driver unloads.
- Room mode
- A standing wave set by room dimensions that makes certain bass frequencies boom or cancel depending on where you stand.
Bass test FAQ
Why can't my laptop play 30 Hz — is it broken?
It's not broken — it's physics. Reproducing 30 Hz means moving a lot of air, which needs a large driver with room to travel. A laptop or phone speaker is a couple of centimetres across and simply can't displace enough air to make deep bass at any real level, so those tones come out silent or as a faint buzz. That's completely normal for small speakers. To judge real bass, test on a subwoofer, tower speakers, or decent headphones.
What frequency is a good subwoofer expected to reach?
A solid home subwoofer reaches down to about 25–30 Hz cleanly; a good one hits 20 Hz, and high-end or larger sealed subs go below that into infrasound. Most music has little content under 30 Hz, so 25–30 Hz already covers the vast majority of bass lines, kick drums, and synths. Movie effects (LFE) dig deeper, which is why home-theatre subs chase 20 Hz and lower. Run the sweep and mark your limit to see where yours actually rolls off in your room.
Is 20 Hz audible, or do you just feel it?
20 Hz is right at the bottom edge of human hearing, and at that frequency perception is mostly tactile — you feel it as pressure and vibration more than you hear a distinct pitch. Whether you perceive it at all depends heavily on level, because your ears are very insensitive down low. Below 20 Hz is infrasound, which you essentially only feel. So on a capable system a 20 Hz tone registers as a physical rumble in the room and your chest rather than a clear note.
Why does my subwoofer rattle on certain notes?
A rattle on specific low notes is almost never the subwoofer itself — it's something nearby resonating in sympathy at that frequency. Common culprits are a loose driver grille, cabinet screws, wall panels, window frames, or objects sitting on the desk or shelf. Use the 40 Hz rattle test to provoke the buzz, then find it by touch: gently press panels and remove nearby items until the rattle stops. If the buzzing comes from the driver itself and sounds like hard cracking, lower the volume — that's the speaker straining.
What volume is safe for a bass test?
Start at about 30% and raise it only gradually. Deep bass moves far more speaker power than it sounds like it does, so sustained low tones at high volume are the quickest way to damage small drivers — you can bottom out a woofer or overheat a voice coil. Stop the moment you hear hard buzzing, cracking, or chuffing, because that's mechanical strain, not music. There's no accuracy benefit to going loud; a moderate level tells you everything about where your system rolls off.
What's the difference between a bass test and a tone generator?
A bass test is a focused tool: it stays in the low frequencies (here 10–200 Hz), adds a descending sweep with a "mark my limit" rolloff finder, names the perceptual band, and includes a rattle test — everything aimed at evaluating low-end. A tone generator is the general-purpose version, letting you dial any exact frequency from 20 Hz to 20 kHz for precise work. Use the bass test to judge and troubleshoot low end; use the tone generator when you need a specific pitch anywhere in the spectrum.
My headphones feel bassy but the sweep rolls off early — why?
Many headphones create the impression of bass by boosting mid-bass (around 80–150 Hz) rather than truly extending into the sub-bass below 40 Hz. That "bass boost" makes music feel warm and punchy but doesn't mean real low-frequency extension. The descending sweep exposes the difference: a pair that stays audible down to 20–30 Hz genuinely reaches the sub-bass, while one that fades around 50–60 Hz just has a lifted mid-bass. It's why two "bassy" headphones can sound completely different on a deep synth line.