Subwoofer test and bass test
Find how low your subwoofer really goes, catch rattles, check the crossover and track down the one note that booms. Phones and laptop speakers cannot play most of these tones.
Volume first. Turn your device volume down before pressing play, then raise it slowly. Tones start quiet on purpose. Very low tones can damage small speakers and woofers if pushed hard. Stop if you hear rattling, distortion or cone slap.
Bass test tones
Tap a tone to play it, tap again to stop. Tick the ones you can hear or feel clearly without distortion.
Tick every tone that plays cleanly.
Low-frequency sweep
A slow glide from 200 Hz down to 15 Hz. The loudness should stay fairly even. A sudden swell is a room mode; a buzz is something rattling (walls, shelves, the sub's own panels). Mark each one.
The WAV is rendered on your device at 48 kHz, 16-bit stereo, using the settings above, so you can play it from a USB stick, a TV or measurement software.
Why one bass note booms: room modes
Between two parallel walls, sound bounces back and forth. When exactly half a wavelength fits between them, the reflections line up into a standing wave: loud in some spots, almost silent in others. These axial room modes happen at frequency = 343 ÷ (2 × distance), and at whole-number multiples. Enter your room size to predict which bass notes will boom.
■ length ■ width ■ height · taller line = stronger (lower-order) mode
| Frequency | Between | Order |
|---|---|---|
| 34.3 Hz | length walls | 1 |
| 42.9 Hz | width walls | 1 |
| 68.6 Hz | length walls | 2 |
| 68.6 Hz | height walls | 1 |
| 85.8 Hz | width walls | 2 |
| 102.9 Hz | length walls | 3 |
| 128.6 Hz | width walls | 3 |
| 137.2 Hz | length walls | 4 |
| 137.2 Hz | height walls | 2 |
| 171.5 Hz | width walls | 4 |
Highlighted rows are modes within 4 Hz of each other; they stack up and cause the worst boom. Play those frequencies with a tone generator and walk around the room: you will find loud and dead spots. Moving the subwoofer or your seat, rather than turning up EQ, is usually the fix.
Setting up a subwoofer, step by step
- Set the crossover. In your AV receiver, set the main speakers to "Small" and the crossover to 80 Hz. If the sub has its own crossover knob, set it to maximum or LFE so the receiver controls it.
- Check the handover. Play the 60, 80 and 100 Hz tones. They should sound about equally loud; a dip at 80 Hz suggests the sub's phase needs flipping (0°/180° switch).
- Find rattles. Run the sweep at a moderate level and fix whatever buzzes: loose picture frames, cabinet doors, window panes.
- Balance the level. The sub should blend in, not announce itself. If you can easily point to where the bass is coming from, it is probably too loud or crossed over too high.
Watch the cone at 10–20 Hz. Large, fast excursion with a slapping sound means the driver is at its limit: stop and lower the level.
Still not working? Describe it
An AI assistant turns your description into step-by-step fixes for your device and system. It only answers audio-equipment questions, and it can be wrong, so check steps against your device's manual.
Questions people ask
What frequency should I use to test a subwoofer?
Start at 50 Hz, which almost every subwoofer plays well, then step down through 40, 30 and 20 Hz to find where output fades. Use the 80 Hz tone to check the crossover blends evenly with your main speakers.
Why can't I hear the 20 Hz tone?
Many compact subwoofers are rated only down to 30–35 Hz, and at 20 Hz you tend to feel pressure more than hear a pitch. Laptops, phones and TV speakers cannot play it at all.
What is the best crossover frequency?
THX recommends 80 Hz for most home theatre systems. Set it higher (100–120 Hz) for very small satellite speakers, and lower (60 Hz) only if your main speakers are large and genuinely reach down that far.
How do I find the best subwoofer position?
Try the "subwoofer crawl": put the sub at your listening seat, play the low sweep or pink noise, and crawl around the floor where the sub could go. Wherever the bass sounds smoothest is where the sub should sit.
Keep testing
- Room mode calculatorPredict booming bass notes from your room size.
- Frequency sweepLogarithmic or linear sweeps over any range and duration.
- Speaker testChannel, range and polarity checks for stereo speakers.