Audio phase test

How to use the audio phase test

Choose in phase or out of phase, then select a test sound: noise or frequency.

In frequency mode, adjust the value in hertz with the − and + buttons or by typing a number directly. The Play button starts the phase test.

What is a phase test used for?

A phase test lets you hear the difference between the same signal on both channels and a signal inverted on one channel.

It can help reveal inverted wiring, stereo playback issues, or a sound that feels less centered.

In phase and out of phase

In phase mode sends the same signal to the left and right channels. The sound should usually feel centered.

Out of phase mode inverts one of the two channels. With headphones, the sound may feel more diffuse or less stable in the center. With speakers, the effect depends heavily on the room, listening position, and equipment.

Noise or frequency

Noise mode uses simple pink noise. It is often useful for quickly hearing the difference between both modes.

Frequency mode uses an adjustable sine wave. It lets you test phase with a precise pitch.

Tool limits

The result depends on the browser, audio system, headphones, speakers, room, and device settings.

The goal is to provide a quick and local check, without installation and without external audio files.

Phase or stereo?

The phase test compares in-phase and out-of-phase signals. To simply check the left, center, and right channels, use the stereo test instead.

Data and privacy

The sound is generated directly in the browser. The selected settings are not sent to the server to use the tool.