Subwoofer Test — Tones & Sweep
Subwoofer test with 20–100 Hz tones, a 20–200 Hz sweep and kick pulses to check extension, rattle and punch. Small speakers stay silent. Free in browser.
Protect your hearing. Start at a low volume. Never raise the volume to make a tone audible. Levels are shown in dBFS, relative to full scale — not SPL.
How it works
Discrete sine presets at exactly 20, 30, 40, 50, 60, 80, and 100 Hz are played with a click-free envelope through createTone, and a 20 to 200 Hz logarithmic sweep runs over 16 seconds through createSweep with a live frequency readout. The kick repeats short 55 Hz sine hits with a fast attack and decaying release at a fixed 96 BPM. Nothing is uploaded or recorded, and no sound plays until you ask for it.
A subwoofer test checks whether your system truly reproduces the bottom two octaves. Play discrete sine tones at 20, 30, 40, 50, 60, 80, and 100 Hz to find your clean extension limit, run the slow 20–200 Hz logarithmic sweep to hear room modes and integration, then hit the 96 BPM kick pulse to judge punch and control. Phone and laptop speakers cannot reproduce anything below about 100–200 Hz, so run this test on a real subwoofer or full-range speakers — and remember that true sub-bass is felt rather than heard. Everything runs live in your browser, and nothing is uploaded or recorded.
Discrete sub-bass tones
Each preset is a continuous sine at exactly the labelled frequency with a click-free attack and release. Work upward from 20 Hz at a low volume and note where clean output begins. Buzzing, port chuffing, or a tone that suddenly jumps in level marks the limit of your speaker, not your hearing.
Slow 20–200 Hz sweep
The sweep runs logarithmically from 20 Hz to 200 Hz over 16 seconds with a live frequency readout. Because the sweep is slow, you can walk the room and feel where bass builds up or cancels. Peaks that follow you are room modes; a null that stays in one spot is a cancellation worth treating with placement or phase before equalisation.
Subwoofer kick pulse
The kick repeats short 55 Hz sine hits at a fixed 96 BPM with a fast attack and a decaying release. It behaves like a metronome for your low end: tight, even hits mean good amplifier damping and placement, while overhang, boom, or rattling objects point at room or mounting problems.
Aliases covered on this page: subwoofer test, bass test, sub bass test, low frequency test, 20hz test tone, and subwoofer kick test.
Frequently asked questions
Why can't I hear the 20 Hz or 30 Hz tones on my phone?
Phone and laptop speakers physically cannot reproduce frequencies below about 100–200 Hz. Their tiny drivers roll off steeply in the bass, so a 20–50 Hz tone may be silent or appear only as faint buzzing and distortion. Use a real subwoofer or full-range speakers to run this test.
Is sub-bass heard or felt?
Below roughly 40–60 Hz, sub-bass is felt rather than heard. You may sense pressure, chest movement, or room vibration even when there is almost no audible pitch. That is normal — judge the lowest presets by air movement and sympathetic rattles as much as by tone.
How do I use the discrete preset tones?
Pick a preset from 20, 30, 40, 50, 60, 80, or 100 Hz and press Play preset tone. Each preset plays a continuous sine at exactly the labelled frequency with a click-free envelope. Note the lowest frequency that produces clean output on your system, and stop immediately if you hear chuffing, buzzing, or port noise.
What does the 20–200 Hz slow sweep tell me?
The sweep moves logarithmically from 20 Hz to 200 Hz over 16 seconds, so each octave gets equal time. Listen and feel for where output fades in, where it peaks from room modes, and where rattles appear. A flat, gradually rising presence means good integration; sudden dropouts or booms point to placement or crossover issues.
What is the kick pulse for?
The kick plays short 55 Hz sine hits with a fast attack and a decaying release at a fixed 96 BPM. It tests punch, amplifier control, and room behaviour under repeating transient load. If hits blur together or the room rings long after each hit, try moving the subwoofer or lowering the crossover.
Is this safe for my speakers and hearing?
Start at a low volume and keep gains modest — sub-bass at high gain can distort or damage cheap speakers. Every signal starts only from a button you press, a persistent Stop and Mute are always available, and levels are reported in dBFS, relative to full scale, never in SPL. Never raise the volume just to make a 20 Hz tone audible.
Which subwoofer test tones should I start with?
Start at 80 Hz at low volume, confirm clean output, then step down through 60, 50, 40 and 30 Hz noting where level drops or distortion appears. Phones and laptops stay nearly silent below 100 Hz, which reflects driver limits rather than failure. Finish with the slow sweep to expose rattles and room-mode peaks.