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Test tones are the quickest way to find out what your subwoofer is really doing in your room. This page plays a steady bass tone at any frequency from 10 to 200 Hz, runs a slow sweep so you can hunt down rattles, and walks you through a simple bass check at your seat with a decibel meter or a phone app. It all runs in your browser, so there is nothing to install or download.
- Play the tones through your subwoofer system. Phone and laptop speakers can’t reproduce deep bass.
- Turn your system volume down first, then raise it slowly.
- Don’t run loud tones below 25 Hz for long. If you hear chuffing, clicking or a slapping sound, stop: that’s the driver at its limit.
- On an iPhone, flip the silent switch off or you may hear nothing.
How to get the tones to your subwoofer
Connect the device playing this page to your system the way you’d normally play music: HDMI from a laptop, Bluetooth, AirPlay or a cable into your receiver or soundbar. Bluetooth is fine for this, since a sine tone doesn’t need a lossless connection.
With an AV receiver, bass management decides what goes to the sub. If your speakers are set to Large, the receiver may send these tones to your front speakers instead. Set the speakers to Small with an 80 Hz crossover (see our crossover settings guide) and the sub will get everything below that. If your sub is wired to a stereo amp, check which input you’re using in LFE vs line-in. Soundbars with a wireless sub handle this automatically.
Finding rattles with the sweep
Use the Sweep tab at a moderately loud level, from 20 to 120 Hz over 60 seconds. Walk slowly around the room while it plays and tap Mark rattle whenever something buzzes. Each mark becomes a button: tap it to play that frequency as a steady tone, which makes the source much easier to track down.
In a living room, the usual suspects are picture frames, window panes, glass shelves, cabinet doors, lamp shades, and the sub itself buzzing against the floor. In a car it’s the license plate, trunk lid, rear deck and door panels. Our guide to fixing subwoofer rattles covers the fixes, from felt pads to sound deadening mat like KILMAT 80 mil.
Checking your bass at the listening seat
The Room check tab turns the tones into a rough frequency response for your seat. You need something to measure loudness: a cheap meter such as the TopTes TS-501B or a free SPL app on your phone. Phone mics are not very accurate in deep bass, but they’re consistent, and consistency is what matters when you compare one tone to the next.
- Set the meter to C-weighting and slow response.
- Hold it at ear height in your main seat, pointed at the ceiling, and keep it in the same spot.
- Play each tone and type in the reading. Five readings is enough for a first look; all seventeen give a much better picture.
- Read the chart: orange dots are peaks, blue dots are dips, and the green band is within 3 dB of your average.
Peaks are easy to tame with EQ, either in your receiver’s room correction or a DSP like the miniDSP 2×4 HD. Our subwoofer EQ guide explains how. Dips are different. They’re caused by sound waves cancelling each other, and boosting them only burns amplifier power. Fix dips by moving the sub (try the “sub crawl” in our placement guide), moving your seat, or adding a second subwoofer.
When you’re ready for proper measurements, a calibrated USB mic like the miniDSP UMIK-1 and free Room EQ Wizard software will show you far more detail than a meter can.
Setting your sub level with bass noise
Switch the Tone tab to Bass noise for a steady rumble between about 25 and 80 Hz. It reads more steadily on a meter than a single tone, which makes it better for level matching. Play your receiver’s own test noise through the front speakers, note the reading, then adjust the sub’s level until the bass noise reads about the same. Many people then add 2 to 4 dB because they like a little extra weight, and that’s fine. Once the level is right, fine-tune timing with our distance and delay guide.
What the frequencies tell you
| Range | What lives there | What to listen for |
|---|---|---|
| 10–20 Hz | Infrasonic effects in some movies | Pressure rather than a note. Only big subs play this cleanly; keep the volume low. |
| 20–30 Hz | Explosions, engines, pipe organ | Where small subs start to fade. A gentle drop here is normal. |
| 30–45 Hz | Weight in movie effects and synth bass | Should be clean and roughly even around the room. |
| 45–70 Hz | Kick drum, bass guitar | The usual range for rattles and for big room peaks. |
| 70–100 Hz | Around the crossover | If you can hear where the sub is, lower the crossover or move it nearer the front speakers. |
| 100–200 Hz | Upper bass, male vocals | Normally played by your main speakers, not the sub. |
Frequently asked questions
Can test tones damage my subwoofer?
They can if you play them very loud for a long time, especially below the frequency your sub is designed for. A pure tone puts continuous energy into the driver, unlike music. Keep the volume moderate, and stop straight away if you hear chuffing, clicking or slapping.
Why can’t I hear the lowest tones?
Two reasons. Human hearing is much less sensitive below about 30 Hz, so a tone that’s playing well can still seem quiet. And most subwoofers roll off somewhere between 20 and 35 Hz. Check your sub’s spec sheet for its lower limit (often shown as “−3 dB” or “−6 dB”).
Why do I hear nothing on my phone or laptop?
Their speakers are tiny and physically can’t move enough air below about 100 Hz. Connect your device to your sound system, or use headphones for a quick check (they can reproduce deep bass, just not the room effects).
Is a phone decibel app good enough?
For comparing one tone with the next, yes. Absolute readings from a phone mic are often several dB off in deep bass, but the shape of your chart is still useful. A dedicated meter or a calibrated USB mic is more reliable.
Why does bass sound much louder in some seats?
Room modes. Bass wavelengths are long enough to bounce between your walls and either pile up or cancel at certain spots. That’s why moving the sub or your seat by a couple of feet can change the bass more than any setting. Our placement guide explains what to try.