Bass test — subwoofer and low frequency test online
Bass test
Press Start for a 200 → 20 Hz sweep followed by eight fixed bass tones. Use Custom tone to hold one low frequency as long as you need.
Start at a moderate volume and raise it slowly — deep bass loads small speakers hardest.
Using headphones? Turn the volume down before you start.
Bass test finished. Note the lowest step you could still hear or feel. A rattle or buzz at one step points to something loose; a small phone or laptop speaker going quiet on the lowest steps is normal — deep bass needs a bigger speaker.
Tone finished.
A bass test plays low frequencies one by one so you can hear how deep a speaker, subwoofer or pair of headphones really goes. This one plays a 20-second sweep from 200 Hz down to 20 Hz, then fixed tones at 100, 80, 60, 50, 40, 30, 25 and 20 Hz, 2.5 seconds each.
The sections below explain how to run a subwoofer test, how to read the lowest step you can hear, and when a rattle means something needs fixing.
Bass test online
An online bass test works because the browser generates each tone itself, so there is no compressed audio file between the test and your speaker. Every step is a pure sine wave at a known frequency, which makes it easy to tell exactly where the bass fades.
| Part | What plays | Length |
|---|---|---|
| Sweep | Sine tone gliding from 200 Hz down to 20 Hz | 20 sec |
| Steps | 100, 80, 60, 50, 40, 30, 25 and 20 Hz | 2.5 sec each |
| Total | Sweep plus eight steps | 40 sec |
The test plays below full scale on purpose. Deep tones make a speaker cone travel much further than midrange sound at the same level, and a small driver pushed hard at 20 Hz will distort before it plays anything useful.
Subwoofer test
A subwoofer test checks three things: that the subwoofer plays at all, how low it reaches, and whether anything rattles. Run the full test with the main speakers playing too, then again with only the subwoofer connected if your receiver allows it.
Step 1
Start quietly
Set the volume low, then raise it during the sweep until the bass is clearly audible but not strained.
Step 2
Listen to the sweep
The level should stay fairly even. A sudden boom at one point is usually the room, not the subwoofer.
Step 3
Note the last step
Write down the lowest fixed tone you can still hear or feel. That is your practical low-frequency limit.
Step 4
Hunt for rattles
If one step buzzes, hold it with Custom tone and touch nearby objects to find what vibrates.
Step 5
Move and repeat
Try another position. In a room, bass often changes more with placement than with settings.
On a phone or laptop, use Custom tone to hold a single low frequency and listen to each end of the device in turn.
Low frequency test: how low your speakers go
A low frequency test tells you where a speaker’s bass ends, and the answer depends mostly on its size. The table below is a guide to reading your result, not a pass or fail score.
| Device | What a normal result looks like | What deserves a second look |
|---|---|---|
| Subwoofer | Clear output down to the lowest steps, even level through the sweep | Silence on every step, or a buzz at one frequency |
| Bookshelf or TV speakers | Output fading somewhere in the lower steps | One speaker of a pair noticeably weaker |
| Headphones | Low tones clear when the ear cushions or tips seal well | One side quieter or rattling |
| Phone or laptop | Little or nothing on the lowest steps | Distortion or crackle on the higher steps |
If a phone speaker crackles even on the highest bass steps, the cause may be dust or water in the grille rather than the test — the online speaker cleaner plays low sweeps meant for that.
Test bass with music
Testing bass with music shows how a system handles real recordings, which fixed tones cannot. Use tracks you already know well from a system you trust, with a sustained low bass line rather than short kick drums, so you can hear whether notes stay even as they go deeper.
On a home theater, run the surround speaker channel test first to confirm the subwoofer channel reaches the subwoofer at all. Music and tones answer different questions. Tones find the exact frequency of a rattle or a drop-off; music tells you whether the balance sounds right. Run the tone test first, fix what it finds, then listen to music. For the full range rather than only the bass, the frequency sweep speaker test covers 20 Hz to 20 kHz.