Hearing & speakers · 16 – 200 Hz
Subwoofer Test Tones
Low-frequency test signals for finding the limits of a subwoofer, a room or your own hearing. Step through the standard frequencies, run a continuous 16–120 Hz sweep with a rattle-finding mode, and compare three bass notes at matched level to hear which ones your setup reproduces.
Start loud enough to hear the tone, never at full volume. Long sub-bass exposure at high level damages drivers more than ears - the cone moves a long way for little audible output and the voice coil heats up. Keep levels modest and sessions short. What you hear is also limited by your playback device and room.
All three play at exactly the same gain. Play them one after another: whichever sounds quieter or vanishes is the one your speakers and room reproduce least.
Ready. Choose a step tone to begin.
The spectrum display shows the energy leaving the mixer. A clean 40 Hz sine reads as a single peak at 40 Hz; any extra peaks are harmonics from your system, not from the file.
| Freq | Wavelength | Typically found in |
|---|---|---|
| 16 Hz | 21.44 m | Infrasonic limit. A 32′ pipe-organ stop, special-effects rigs - felt more than heard. |
| 20 Hz | 17.15 m | Lower edge of hearing for most people. Synthesised sub-bass, earthquake and thunder rumble. |
| 25 Hz | 13.72 m | Large pipe organ and cinema LFE. Most home subwoofers already roll off here. |
| 30 Hz | 11.43 m | Typical small subwoofer limit; club systems and 30 Hz test tones. |
| 35 Hz | 9.80 m | Around the low B of a 5-string bass (≈ 30.9 Hz) and kick-drum fundamentals. |
| 40 Hz | 8.57 m | The low E of a 4-string bass guitar (41.2 Hz); bass-heavy electronic music. |
| 50 Hz | 6.86 m | Mains hum in 50 Hz regions; bass punch; the practical upper limit of many subwoofers. |
| 60 Hz | 5.72 m | Mains hum in 60 Hz regions; bass-guitar body; the warm low end. |
| 70 Hz | 4.90 m | Low end of male voice fundamentals and floor toms. |
| 80 Hz | 4.29 m | Kick-drum body; the lower limit of many bookshelf speakers. |
| 90 Hz | 3.81 m | Low male vocals and bass midrange; the chest-thump region. |
| 100 Hz | 3.43 m | Bass punch; snare fundamental; a common subwoofer crossover point. |
| 120 Hz | 2.86 m | Upper bass / low midrange; bass-guitar harmonics, low cello (≈ 65–130 Hz). |
| 150 Hz | 2.29 m | Upper bass; male voice and low guitar - most speakers reproduce this with ease. |
| 200 Hz | 1.72 m | Low midrange, not sub-bass: the boundary between bass and mids. |
Wavelength uses the speed of sound at 20 °C (343 m/s): λ = 343 ÷ f. A wavelength longer than the room is why the lowest tones need large drivers and large cabinets to be produced at all.
Why does my system seem silent at 16–30 Hz?
Because almost no playback device reproduces those frequencies at useful level. A 16 Hz wave needs a quarter-wavelength of over five metres to radiate well, so it takes a large driver in a large box. If you hear nothing at 20 Hz, that is a fact about the speaker, not a fault - check the wavelength column to see why the low steps are the hardest.
The A/B compare plays three tones at the same level - what am I listening for?
Which of 20, 40 and 80 Hz sounds quieter or disappears. Play them one after another at the same gain: if 20 Hz is far quieter than 40 and 80, your room and speakers are rolling off the bottom. The room matters as much as the driver - a 40 Hz standing wave can make one listening position boom and another cancel completely.
Will a long sweep damage my speakers?
It can. Sub-bass at high level is hard on drivers because the cone has to move a long way for very little audible output; a driver can be pushed to its limit while sounding quiet. Heat builds in the voice coil during sustained low tones. Keep the level modest, keep durations short, and never run a sweep at full volume.
Why do low frequencies sound “slow” or “bloated”?
Long wavelengths interact with the room. A 40 Hz tone has a 8.6 m wavelength, so reflections from walls arrive far out of phase and set up standing waves: some seats boom, others cancel. That is also why tone-quality claims are limited by the playback device - the file is a clean sine, but what you hear is the sine after it has bounced around your room.
Step tones first
Play the step tones from the top down - start at 200 Hz where almost everything reproduces, then work downward until a tone stops getting louder as you expect. The frequency where the level drops away is the useful low limit of your system in its position. Write the numbers down; a difference of two or three steps is normal, a cliff of six is a real roll-off.
The sweep and the rattle mode
A sweep moves continuously through the band, which is far better for finding narrow problems than stepping. Switch on Find rattles and the sweep repeats with a triangle wave, whose extra harmonics shake loose the buzzes a pure sine misses - a picture frame, a loose grille, a cable against a panel. Walk around the room while it runs; a rattle you can only hear from one seat is a room problem, not a speaker one.
Why the A/B compare is level-matched
Human hearing judges loudness by more than amplitude, so a fair comparison holds everything else constant. The three comparison tones are generated at identical gain; if 20 Hz sounds quieter than 80 Hz, that is your system, not the signal. This is the honest way to find which bass notes disappear in your room.
What this page cannot tell you
It generates a mathematically clean signal. What reaches your ears is that signal after it has passed through your device, your amplifier, your speakers and your room. Claims about tone quality made with these tones are always claims about that chain, limited by every part of it - the generator side of the chain is exact.