Multichannel Sound Test

The first number describes the main full-range channels, while the number after the decimal point identifies the low-frequency effects channel, or LFE. “.1” does not mean that a subwoofer plays only one percent of the sound. It is a separate channel intended for low-frequency effects. The crossover between the subwoofer and the other speakers is controlled by your receiver or operating system, not by this test.

• Mono contains one audio signal. A stereo output may reproduce that signal through both the left and right speakers.
• Stereo uses front left (L) and front right ® channels.
• 2.1 combines a stereo pair with a subwoofer. Browsers may rely on the device or driver’s bass management to route low frequencies, so behavior can vary.
• 4.0 uses front left and right plus rear left and right, without a center channel or discrete LFE channel.
• 5.1 adds a center channel, LFE, and rear left and right to the front pair. The center commonly carries dialogue, while the rear channels provide ambience and directional effects.
• 7.1 expands 5.1 with a pair of side surround channels, helping distinguish sounds beside the listener from sounds behind them.

Your system is routed correctly when each signal comes only from the highlighted speaker, every side matches the diagram, and similar speakers have a reasonably even level at the listening position. The low-frequency channel should reach the subwoofer, although it may sound quiet on small systems or be redirected to the main speakers.

• If a left signal comes from the right, or a rear signal comes from the front, inspect the cables, terminals, and channel assignments in the audio driver or receiver.
• If rear and side signals play through the front speakers at the same time, the device, operating system, or browser is probably downmixing the output to stereo.
• If one channel is silent, check speaker power, the connection, its channel level, and the selected output configuration.
• If one speaker is noticeably louder, compare channel levels and speaker distances in the receiver first. Accurate level calibration requires a measurement microphone or sound level meter.
• If LFE is barely audible, check the subwoofer’s power and volume plus the crossover, Bass Management, LFE, and Subwoofer settings in your audio system.

Multichannel audio must pass through the complete playback chain: browser, operating system, driver, cable, television or receiver, and finally the speakers. Any part of that chain can restrict the signal to two channels. The maximum channel count shown on this page is the value reported to the browser by the current audio output. It does not guarantee that every physical speaker is connected or configured correctly.

• Select the multichannel output device and configure a 5.1 or 7.1 speaker layout in Windows, macOS, or the driver control panel.
• For an AV receiver, use a connection that can carry multichannel PCM, such as compatible HDMI. A standard 3.5 mm analog connection normally carries stereo only.
• Disable modes that force all content to stereo, then try the receiver’s direct or multichannel PCM playback mode.
• Try an up-to-date version of another browser. The available channel count and Web Audio behavior depend on the browser, operating system, and audio driver.
• Bluetooth headphones and most built-in laptop speakers are stereo devices. Virtual headphone surround is processed differently and does not create separate physical output channels.

The page generates test tones with Web Audio directly on your device and routes them to individual channels. It does not record the microphone, upload audio files, or send sound to a server. The test is useful for an initial check of speaker assignment, connection integrity, and channel availability after installing equipment or changing settings.

It does not measure frequency response, latency, phase, room acoustics, or absolute sound pressure, and it cannot replace a receiver’s microphone-based calibration. To compare left and right channels separately, use the headphone test. Open the subwoofer test for a focused low-frequency check, or view the audio codecs page to inspect playback format support.