Speaker & Headphone Test
Find out whether every speaker plays from the right place, in phase and in balance.
Volume
−24 dBTurn your system volume down before the first test, then raise it slowly. Sounds start quietly and fade in. Stop at once if you hear rattling or distortion, and never play low tones loudly on small laptop or phone speakers.
Which speaker is which?
This browser has no speech voices, so the speaker names are shown on screen only.
The voice plays through your normal speakers and only names the speaker; the noise that follows comes from that one channel. Hearing it from somewhere else means the speakers are swapped or the system is set up differently. Speaker positions follow ITU-R BS.775 for 5.1 (fronts at ±30°, surrounds at about ±110°).
Are the speakers wired in phase?
Sit in the middle between the speakers (or wear the headphones) and play both versions. The same noise plays from both sides; in the second one the right side is inverted.
Which one sounded fuller, with more bass and a clear centre?
Left / right balance
centrePlay the noise, then move the slider until the sound seems to come from straight ahead. The page tells you how much quieter the weaker side is.
Bass and subwoofer (20–200 Hz)
–The sweep rises smoothly from 20 to 200 Hz over 30 seconds. Press I can hear it now when the bass first becomes audible. Buzzes and rattles on the way point to loose parts or a resonating room.
About the Speaker & Headphone Test
Check that your speakers or headphones are connected the right way round. Press a speaker and a short burst of noise plays from that channel only, after a spoken cue that names it, so you hear at once whether left is really left. When your system is set to 5.1 or 7.1, the page offers every surround channel and the subwoofer.
Three more checks find common set-up faults: the phase test shows whether one speaker is wired in reverse (+ and − swapped), the balance test measures how much quieter one side is, and the bass sweep from 20 to 200 Hz finds where your speakers or subwoofer start to play, and any rattles on the way. Every sound is generated in your browser, starts quietly and fades in.
How to use it
- Turn your system volume down, then set the Test volume slider (it starts low).
- Press Left and Right (or Play all in turn) and check that each sound comes from the speaker the voice names. For surround, choose 5.1 or 7.1 under Speaker setup if the page enables it.
- Play In phase and Out of phase, then answer which sounded fuller: the page tells you whether a speaker is wired in reverse.
- Play the balance noise and move the slider until the sound is centred to see how much quieter one side is.
- Play the bass sweep and press I can hear it now when the bass becomes audible; use the single tones to check a frequency again.
Examples
Press Left
The voice says “Left” but the noise comes from your right ear: the headphones are reversed (or the left and right cables of a speaker set are swapped).
Play In phase, then Out of phase
The second sounds fuller → “One speaker is probably wired in reverse” — swap the red and black wires on one speaker.
The noise sounds centred with the slider at 15% right
“The right side is about 2.1 dB quieter.”
Bass sweep 20→200 Hz
“You first heard the sweep at about 71 Hz.” — typical for small speakers; a subwoofer extends this lower.
How the channels are addressed
The page sends each test sound to one output channel with the Web Audio API, so the sound cannot leak into the other speakers. For stereo the order is left, right; for 5.1 the Web Audio standard defines the order L, R, C, LFE, SL, SR (front left, front right, centre, subwoofer, surround left, surround right). For 7.1 the page uses the order Windows uses: L, R, C, LFE, back left, back right, side left, side right. If a 7.1 system plays the back sounds from the side speakers, that system orders the last four channels the other way.
Surround channels only exist when the operating system’s output is set to 5.1 or 7.1 and the browser reports enough output channels (AudioContext maxChannelCount). Phones, laptops and most headphones report two.
Phase and polarity
Every speaker has a + and a − terminal. If one speaker of a pair is connected the other way round, its cone moves out while the other moves in: bass cancels and the sound seems to come from nowhere in particular. The test plays the same pink noise from both channels, once identical (in phase) and once with the right channel inverted (out of phase). With correct wiring the first sounds fuller and centred; if the second sounds fuller, one speaker is reversed.
Balance, measured
The balance slider uses the equal-power law of the Web Audio StereoPannerNode: at position p (−1 to +1) the left gain is cos((p+1)·π/4) and the right gain sin((p+1)·π/4). When the sound seems centred, the ratio of the two gains is the level difference your ears compensated for, shown in decibels. Differences under about 1 dB are hard to hear; several decibels point to a balance setting, speaker placement or a fault.
The bass sweep
The sweep rises exponentially (equal time per octave) from 20 to 200 Hz over 30 seconds: its frequency at time t is 20 × 10^(t/30) Hz. Small laptop and phone speakers usually start somewhere above 100 Hz, desk speakers around 60–80 Hz, and a subwoofer can reach 30 Hz or lower. Your hearing is much less sensitive at low frequencies, so a frequency you cannot hear at a low volume may appear when it is louder — keep the volume moderate.
Limitations
- The page plays through your current output device. To test another speaker or headphones, switch the output in your system’s sound settings.
- Spoken cues use your system’s speech voices and play through the normal speakers; they name the speaker, the following noise is the actual channel test.
- 5.1 and 7.1 tests need a browser and system output that report 6 or 8 channels; Bluetooth headphones and most phones offer stereo only, and “virtual surround” headphones cannot be tested channel by channel.
- Results depend on the room and where you sit; this is a listening check, not a calibrated measurement.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I test left and right on headphones?
Put the headphones on, press Left and then Right. Each noise must come from the ear the voice names. If they are swapped, check the L/R marks on the headphones; if one side is silent, try another cable or device.
Why are 5.1 and 7.1 greyed out?
Your browser reports only two output channels. Set the output to 5.1 or 7.1 in the system (Windows: Control Panel → Sound → choose the device → Configure; macOS: Audio MIDI Setup → Configure Speakers), connect the receiver by HDMI or a multichannel interface, then reload the page.
Is the test safe for my speakers?
Sounds start at −24 dB on the slider, fade in, and the first sound of a visit ramps up from silence. Still, turn the system volume down first and avoid loud low tones on small speakers: if you hear distortion or rattling, stop.
Why does the voice come from both speakers?
Browsers send speech from the system’s voice directly to the speakers, so it cannot be steered to one channel. The voice only says which speaker comes next; listen to where the noise comes from.
What does it mean if the in-phase and out-of-phase sounds are the same?
Usually that you sit far off-centre or the speakers are very far apart. Sit in the middle, closer to both, and listen again. On headphones the difference is always obvious.
Why can I barely hear the lowest tones?
Human hearing is much less sensitive below about 100 Hz, and small speakers cannot move enough air for deep bass. That is normal; the sweep shows where your speakers start to play.