Bass Extension Test

This bass extension test plays a descending sweep from 200 Hz down to 20 Hz (or step through discrete tones) — mark the moment the bass stops being audible or felt. That point is a rough estimate of how low your speakers, headphones, or subwoofer usefully reach, compared with typical ranges for different gear.

⚠ This is a subjective listening aid, not a measurement. Where you stop hearing bass depends heavily on how loud you play it — your ears are far less sensitive at low frequencies (the equal-loudness effect), so a quiet 30 Hz tone can be inaudible from a speaker that reproduces it perfectly well. “Inaudible” is not the same as “not produced.” Room gain, headphone seal, where you sit, and the device all shift the result, and this is not a −3 dB roll-off measurement. For a real low-frequency limit, use a measurement microphone with software like REW. Safe-volume warning: deep bass moves a lot of air — start quiet, and protect your hearing and your speakers (large cone excursion at high level can damage woofers and especially small drivers and earbuds).

Test mode

Sweep length (s)

Volume

Press “Play test” to begin. Start at a low volume and raise it only until 100–120 Hz is comfortably loud, then leave it — do not crank the volume chasing the lowest notes.

Typical low-frequency limits (rough, published guidance — not a guarantee for your gear)

These are broad, commonly-cited ballparks. Manufacturer specs vary widely, and a vendor’s “frequency response” number is only meaningful with a tolerance (e.g. ±3 dB) and a measurement method behind it.

How It Works

The tool generates a single pure sine tone in your browser with the Web Audio API and sends it straight to your device’s audio output — that produced tone is the intended sound; nothing is recorded and your microphone is never used. In sweep mode the tone’s frequency glides smoothly from 200 Hz down to 20 Hz over the time you set, giving you a complete descending sweep so you hear the bass descend and gradually fade as you reach the limit of what your gear (and your ears, at that level) can reproduce. In steps mode it holds each tone — 200, 160, 125, 100, 80, 63, 50, 40, 31.5, 25 and 20 Hz — for about two seconds so you can judge each one cleanly and even feel it physically. If you instead want to detect which frequencies are present in an incoming signal rather than generate them, the frequency sweep detector listens via your microphone and reports the frequencies it picks up.

As the tone plays, the big readout shows the current frequency. When the bass becomes inaudible or you can no longer feel it, press “mark limit”. The tool freezes the frequency at that instant and reports it as your approximate low-frequency limit, then places it on a scale of typical ranges so you can see roughly where your earbuds, laptop, bookshelf speakers, floorstanders, or subwoofer sit. To keep the comparison honest the tone starts quiet and the volume is capped well below full scale — you should set a comfortable mid-bass level around 100–120 Hz and leave it there, because raising the volume to chase the lowest notes will push your “limit” lower and tell you more about loudness than about the gear.

Why this can’t be a true measurement: human hearing is dramatically less sensitive in the deep bass (the well-known equal-loudness contours, formalised in ISO 226), so the same 30 Hz tone can be obviously audible when loud and completely silent when quiet — even though the speaker reproduces it identically both times. On top of that, room gain can boost bass near walls and corners — particularly below the room’s Schroeder frequency where modal behaviour dominates — a headphone’s seal against your head changes its bass dramatically, and your seating position interacts with room modes. These factors all affect the perceived bass response you experience during the test. A real low-frequency limit (the −3 dB or −6 dB point) requires a calibrated measurement microphone and software such as Room EQ Wizard (REW); treat this tool as a quick, fun, relative listening check rather than a spec sheet. If you are curious about bass content below the audible threshold entirely, the infrasound frequency detector covers frequencies below 20 Hz that are felt rather than heard.

Frequently Asked Questions

Does this measure how low my speakers actually go?

No. It tells you the lowest tone you can hear or feel right now, at this volume, in this room, on this device — which is a subjective listening point, not a calibrated measurement. Your ears are far less sensitive in the deep bass, so where you stop hearing it depends heavily on level. A speaker can reproduce a tone perfectly while you still cannot hear it because it is quiet. For a real low-frequency limit (the −3 dB point) you need a measurement microphone and software like REW.

Why does turning up the volume make me hear lower?

Because of the equal-loudness effect (the ISO 226 equal-loudness contours): the human ear needs much more sound energy to perceive deep bass than it does for midrange, and that gap grows as the tone gets lower. So louder playback makes very low tones audible that were silent before — the gear has not changed, only your perception of it. That is exactly why the tool starts quiet and caps the volume: set a comfortable mid-bass level and leave it, or your result drifts lower the more you turn it up.

I can feel the bass but not hear it — what should I mark?

Mark the point where you can neither hear nor feel a clean low tone. Feeling deep bass in your body or in the room is a legitimate part of bass extension, especially with a subwoofer, so include it. Be careful, though: a rattling, buzzing, or distorted sound is your driver struggling or being driven past its limits — that is not clean extension, and you should turn the volume down rather than push it.

What are the typical bass limits I'm being compared with?

As rough, commonly-cited ballparks: earbuds and many phones roll off around 100 Hz; laptop and small tablet speakers around 150–200 Hz; bookshelf speakers reach roughly 50 Hz; tower/floorstanding speakers around 35 Hz; and dedicated subwoofers reach 20–30 Hz. These are broad typical figures, not guarantees — real models vary widely, and a meaningful spec always cites a tolerance such as ±3 dB and how it was measured.

Is it safe to play these low tones loud?

Play them gently. Deep bass requires large speaker cone movement, and pushing a small driver, earbud, or laptop speaker hard at 20–40 Hz can distort or damage it; even big woofers and subs can be over-driven. High sound levels also risk your hearing, and very low tones can be loud without seeming so. Start quiet, raise the level only until mid-bass is comfortable, and stop if you hear buzzing, rattling, or distortion. Nothing is recorded or transmitted — the tone is generated entirely in your browser.

Why do headphones often reach lower than my speakers in this test?

Headphones create a sealed cavity between the driver and your eardrum. That small sealed volume, combined with the headphone’s own driver, typically gives a much flatter low-frequency response relative to room speakers — there are no room modes, and any acoustic seal (especially over-ear and in-ear designs) dramatically boosts perceived bass. Open-back headphones have less seal and usually show a higher measured limit in this test. By contrast, desktop or bookshelf speakers produce bass that interacts with the room, so what you hear depends heavily on placement and room acoustics rather than the speaker alone.

Why does a ported (bass reflex) subwoofer behave differently from a sealed one near its low-frequency limit?

A sealed subwoofer rolls off gradually (12 dB/octave below its tuning frequency), so the descending sweep fades smoothly. A ported (bass reflex) design uses a tuned port to boost output near the port-tuning frequency, giving a flatter response above that point but a much steeper rolloff (24 dB/octave) below it. In this test a ported sub may seem to hold its level well, then suddenly go silent — that sharp drop is characteristic of port tuning. Passive radiator designs behave similarly to ported ones. The distinction matters when interpreting your mark: a gradual fade suggests sealed, a sudden cutoff suggests ported near its tuning point.

What does 20 Hz actually feel like, and why can I feel it but not hear it?

Human hearing typically begins to lose sensitivity below about 40–50 Hz and the official lower limit of audible sound is defined at 20 Hz, though very few people can hear a 20 Hz tone at moderate levels. What you do experience is a physical pressure sensation — a low throbbing or tactile vibration felt in your chest, seat, or via the floor. This is infrasound-adjacent tactile bass, and it is real and useful, especially in cinema and music production where sub-20 Hz content creates felt impact. Whether you call it “audible” is somewhat subjective, which is why the tool asks you to mark the point where you can neither hear nor feel the tone.

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