An online speaker test for stereo, bass, treble and phase
The speaker test sends sound exactly where you choose — the left speaker, the right speaker or both — and lights up the speaker that should be playing, so you can tell in a second whether a channel is silent or the two are swapped. A 20 Hz to 20 kHz sweep checks how deep the bass goes and how high the treble reaches, and a phase test reveals a speaker wired backwards.
Use it for new headphones or earbuds, laptop and phone speakers, a soundbar, a PC speaker set or a hi-fi connected to your computer. It is also a quick way to confirm Windows, macOS or Android is sending audio to the device you expect.
All sounds are generated in your browser with the Web Audio API; nothing is downloaded, recorded or sent anywhere.
How to use the Speaker Test
- Turn your device volume down, then set the Master volume slider — 30 % is a sensible start, especially with headphones.
- Press Left only, Right only and Both. The speaker that lights up on screen should be the one you hear. Try Sweep left → right to hear the sound travel across.
- Press Play sweep. Press Mark this frequency when you first hear the tone and again when it fades out — those two marks are your speakers’ (and ears’) usable range.
- Press Play phase test, listen, then press Invert right channel. In phase should sound fuller and centred; inverted should sound thin and hard to place.
- Press Stop all sound when you are done.
Speaker Test features
True stereo placement
Tones are panned with the browser’s StereoPannerNode so the left and right channels are isolated, with a visual indicator and a live level meter for each side.
Choice of test tones
Test with 110 Hz bass, 440 Hz (concert A), 1 kHz or 4 kHz to check small earbuds and large woofers alike.
Logarithmic frequency sweep
An exponential sweep from 20 Hz to 20 kHz over 10, 20 or 40 seconds, with the current frequency displayed and a mark button to record your limits.
Phase (polarity) test
Low-passed noise in both channels with a one-click polarity flip of the right channel to expose mis-wired speakers.
Volume safety
A master volume slider that starts at 30 %, smooth fade-ins to avoid clicks, and sound stops automatically when the tab is hidden.
Output channel count
Shows how many channels your current audio device reports, so you know whether a surround receiver is in stereo mode.
What the frequency sweep tells you
Human hearing spans roughly 20 Hz to 20 kHz in children; the top end falls with age, so many adults over 40 hear little above 14–16 kHz, and over 60 often below 12 kHz. Speakers have their own limits: a phone speaker may start at 400–600 Hz, a small bookshelf speaker at 60–80 Hz, and a subwoofer at 25–40 Hz. When you mark the first frequency you hear, you are measuring the speaker’s bass limit (unless your ears give out first, which is not the case for bass). The last frequency you hear is the lower of the speaker’s treble limit and your own hearing limit.
The sweep is exponential, meaning each octave takes the same amount of time, which matches how we hear pitch. Listen for rattles or buzzing at particular frequencies (a loose grille or cabinet panel), sudden dips or jumps in loudness (crossover problems or room resonances) and distortion at the bottom end when the volume is high.
| Band | Frequency | What lives here |
|---|---|---|
| Sub-bass | 20–60 Hz | Kick drum weight, cinema rumble; needs a subwoofer or large woofer |
| Bass | 60–250 Hz | Bass guitar, warmth of voices |
| Mid-range | 250 Hz–4 kHz | Speech intelligibility, most instruments |
| Presence / treble | 4–10 kHz | Consonants, cymbals, clarity |
| Air | 10–20 kHz | Sparkle and sense of space; first to go with age |
Speaker not working? Troubleshooting checklist
- No sound anywhere: check the system output device (Windows: click the speaker icon in the taskbar; macOS: System Settings → Sound → Output), make sure the browser tab is not muted, and raise the Master volume slider here.
- One channel silent: push the 3.5 mm plug fully in, try another cable or port, and check the left/right balance in the sound settings — a balance slider at one extreme is a common cause.
- Left and right swapped: the speakers or plugs are reversed. Swap the cables, or on headphones check the L / R markings.
- Thin, hollow sound that is hard to locate: run the phase test; if “inverted” sounds better than “in phase”, one speaker has + and − wires swapped at the amplifier or speaker terminals.
- Bluetooth speaker or headphones: some switch to a low-quality “hands-free” mode when the microphone is active. Close apps using the mic and reconnect.
- Surround systems: browsers normally output two channels. The receiver may upmix to 5.1 or 7.1; use its own test-tone mode to check centre, surround and subwoofer channels individually. Pair this test with the Mic Test for a full call check, or use the Tone Generator for a steady tone at any frequency.
Speaker Test FAQ
How do I test my left and right speakers?
Press “Left only” and “Right only”. The speaker icon that lights up on screen is the one that should be playing. If the other speaker plays, the channels are swapped at the plug or in the wiring; if nothing plays on one side, check the balance setting and the cable.
Is it safe to run the frequency sweep with headphones?
Yes, if you start quietly. Keep the master slider at 30 % or lower and your device volume moderate. High frequencies can feel piercing even at the same level, so lower the volume if the top end becomes uncomfortable.
Why can’t I hear anything below 60 Hz or above 15 kHz?
Small speakers and earbuds physically cannot reproduce very low frequencies, and adult hearing naturally loses the top octave with age. Try the same sweep on headphones to separate the speaker’s limits from your own.
Does this speaker test work with 5.1 or 7.1 surround sound?
Partly. Web pages normally output stereo, so the test drives left and right; your receiver may spread that across other speakers but the centre, surround and subwoofer channels are not addressed directly. Use the receiver’s or sound card’s own channel test for those.
What does the phase test show?
Whether your two speakers move in step. In phase, bass is full and the sound image sits between the speakers. Out of phase (one speaker wired backwards), bass cancels and the sound seems to come from everywhere and nowhere. If the inverted button makes things sound better, swap the + and − wires on one speaker.
Does the test download or record anything?
No. Every tone and the noise are synthesised in your browser with the Web Audio API, and the microphone is never used.