Speaker Test
Balance Left & Right Audio With Free Tool

Balancing your left and right speakers is completely free and requires no registration. Open this page in Chrome, Edge, or Firefox with your speakers or headphones connected. Click the Left Channel Only button and confirm you hear sound only from the left side. Click Right Channel Only and confirm sound comes only from the right side. Then click Alternating L/R and watch the live balance meter needle. If the needle swings equally far to each side and both sound equally loud, your balance is correct. If one side sounds louder or the needle swings further in one direction, you have a channel imbalance. The imbalance meter shows the exact dB difference between channels. Check your operating system audio settings or amplifier balance control and adjust until the imbalance reading reaches 0.0 dB. No registration, no download, and no microphone are required.

The Lissajous oscilloscope in our free online speaker test plots the left channel signal on the horizontal X-axis against the right channel signal on the vertical Y-axis simultaneously. The resulting shape reveals important information about the stereo relationship between your channels. When you play a test tone through both channels simultaneously with equal level and phase, you should see a diagonal line going from the bottom-left to the top-right corner of the scope. This indicates the channels are identical and in phase. When you play a true stereo signal such as music or a sweep with different content on each channel, the figure opens into an ellipse or circular shape, with wider shapes indicating more stereo separation. When you play the left channel only, the line is horizontal. When you play the right channel only, the line is vertical. If during a both-channels test the line goes from top-left to bottom-right instead of bottom-left to top-right, one of your speakers is wired out of phase. This is the most reliable way to detect phase polarity issues in a speaker installation. Our free Lissajous scope requires no registration to use.

The stereo width imager in our free online speaker test is a horizontal display that shows the real-time distribution of audio energy across the stereo field from hard left to hard right. Content that is identical on both channels, such as a mono signal or a both-channels test tone, appears as a bright line in the centre of the display. Content that is exclusively on the left channel appears as energy at the far left of the imager. Content exclusively on the right channel appears at the far right. True stereo content such as music or a binaural beat test shows energy distributed across the full width of the imager. The stereo imager is useful for confirming that a both-channels test is genuinely playing through both channels, identifying whether your system is collapsing stereo to mono such as some Bluetooth speakers do, and checking that alternating left/right tests are switching correctly between channels. No registration is needed to use the stereo imager.

Fixing channel imbalance depends on where in your audio chain the imbalance is occurring. Use our free speaker balance test to first confirm which channel is louder and by how many dB. For a software balance setting, check your operating system. In Windows right-click the volume icon in the taskbar, open Sound settings, select your output device, click Properties and look for a balance or channel level slider. On macOS open System Preferences then Sound and check for a balance control under the Output tab. In many audio driver control panels there is an additional balance or equalisation setting. For an amplifier or receiver, the balance knob may have drifted from the centre position. For headphones, imbalance of less than 3 dB is within normal manufacturing tolerance. Larger imbalances in headphones may indicate a driver failure and the headphones may need repair. For speakers, check that the positive and negative wires are correctly connected to each speaker terminal. Our free online tool lets you verify balance after each adjustment without registration.

During the full frequency sweep in our free online speaker test you should hear a continuously rising tone starting from a very low subsonic rumble at 20 Hz and rising smoothly through bass, midrange, treble, and into a high-pitched whistle before reaching 20 kHz. The key things to listen for are consistency on both channels, meaning neither side should drop out, distort, or change character relative to the other at any point in the sweep. The low frequency portion below 80 Hz may be inaudible through small speakers or laptop speakers because those devices cannot reproduce sub-bass. The very high frequency end above 15 kHz may become inaudible depending on your age and hearing ability. Any specific frequency where you hear buzzing, rattling, or distortion indicates a mechanical resonance in your speaker cabinet, a loose component, or driver damage. Watch the FFT spectrum analyser while the sweep runs to see the sweeping peak move across the display. If one channel shows noticeably lower peaks than the other at the same frequency point you have a frequency-specific channel difference that may indicate driver aging or damage.

The binaural beat test in our free online speaker test plays a 400 Hz tone through the left channel and a slightly different 410 Hz tone through the right channel simultaneously. When you listen through headphones with good stereo separation, your brain perceives a third beating frequency at the difference between the two tones, which in this case is 10 Hz. This beating sensation is a binaural beat. The binaural beat test is useful for verifying that your headphones or earphones are genuinely passing two separate independent channels to each ear rather than mixing the channels together. If you hear a clearly audible 10 Hz beating pulse, your headphones have good stereo channel separation. If you hear only two steady tones without a beat, or if the beat is very faint, your headphones may be leaking signal between channels or your audio system may be summing the stereo signal to mono. Binaural beats only work through headphones and will not create the beating sensation through open speakers because the room acoustics mix the two tones in air before they reach your ears. No registration is required to run this test.

Pink noise and white noise are both random noise signals that contain all audible frequencies but distribute energy differently. White noise has equal energy at every individual frequency from 20 Hz to 20 kHz. Because there are many more high frequency bands than low frequency bands, white noise sounds bright and harsh, with a strong hiss. Pink noise has equal energy per octave, meaning each octave band such as the 100 to 200 Hz octave and the 1 to 2 kHz octave contains the same amount of energy regardless of how many individual frequency bins that octave contains. This results in pink noise having more low frequency energy than white noise relative to the highs, and pink noise sounds more balanced and natural to the human ear. Pink noise is the professional standard for speaker level matching and frequency response measurement because its energy distribution matches the way human hearing perceives loudness across the frequency range. Use the pink noise test to match left and right channel levels by ear, and use the white noise test to specifically check high frequency extension and tweeter health. Both tests require no registration.

Yes, our free online speaker test works with Bluetooth headphones, earbuds, and Bluetooth speakers. Connect your Bluetooth device through your operating system Bluetooth settings first and set it as the default audio output. Your browser will then route all test tones to the Bluetooth device. There are some important considerations when testing Bluetooth devices. True wireless stereo earbuds that have a separate driver in each ear work correctly with all tests including the binaural beat test. Mono Bluetooth speakers that combine left and right channels into a single output will play all test tones including the left-only and right-only tests through the single speaker because both channels are mixed before output. Bluetooth codecs add processing latency which does not affect the tone tests but means the Lissajous scope timing may show slight phase offsets not related to the speaker polarity. Some Bluetooth headsets used for voice calls automatically switch to a narrowband call codec when connected, which limits high frequency response to 4 kHz. Switch to media audio mode to hear the full frequency sweep. No registration is required.

Speaker phase describes whether the speaker cone moves in the same direction as other speakers in response to the same electrical signal. When all speakers are in phase, the cones all push and pull in unison, creating coherent, full-sounding audio with solid bass. When one speaker is wired out of phase, meaning its positive and negative terminals are reversed, its cone moves in the opposite direction to the other speakers. When you play the same bass frequency through two out-of-phase speakers in the same room, the pressure waves from the two cones cancel each other out. The result is dramatically thin, weak bass and a vague, diffuse stereo image. Our free phase test plays a 440 Hz tone through both channels simultaneously. If your system is correctly in phase, you should hear a clear centered sound with full body. If one speaker is out of phase, the bass will sound thin and the sound image will seem to come from the sides or from nowhere specific rather than from between the speakers. Watch the Lissajous scope during the phase test. A diagonal line from bottom-left to top-right means in phase. A diagonal line from top-left to bottom-right means out of phase.

Our free online speaker balance test works in all modern browsers that support the Web Audio API. Google Chrome on Windows, macOS, Linux, Android, and ChromeOS provides the best performance with the most accurate stereo channel separation and the lowest output latency, resulting in the cleanest Lissajous scope display and most precise tone generation. Microsoft Edge on Windows and macOS performs identically to Chrome as both use the same Chromium audio engine. Mozilla Firefox on Windows, macOS, and Linux fully supports all 16 test tones, the frequency sweep, the Lissajous scope, the stereo imager, and the FFT spectrum analyser. Opera on desktop is fully compatible. Safari on macOS 12 and later and iOS 14 and later supports all tests with some minor differences in stereo channel handling on iOS. For the most accurate balance measurement and Lissajous display we recommend Chrome or Edge on a desktop computer with a wired audio connection. On mobile devices, ensure your phone is not in silent mode and that media audio is enabled in your Bluetooth device settings. All tests are completely free, require no registration, and no audio data is ever recorded, stored, or transmitted from your device.