Speaker Test

First confirm your headphones or speakers are physically oriented correctly (the L/R markings). If they are, check your operating system's audio settings or your audio interface software for a channel-swap or balance option.

440 Hz (the default) is comfortable and audible on any speaker. Sweep lower (60–120 Hz) to check bass response and higher (8–15 kHz) to check treble, small laptop speakers naturally reproduce little below ~200 Hz.

Check the output device selected in your OS (audio may be routed to a display or Bluetooth device), the system volume and mute state, and the volume slider in the tool. Browsers also require a click before playing audio. Press one of the test buttons.

Sustained loud tones are unpleasant and can be harmful to hearing at high volumes. Start with the tool's volume low, especially with in-ear headphones, and raise it gradually.

It plays one tone through both channels either in phase or with the right channel inverted 180°. Drop the frequency to the bass region (60–150 Hz) and compare: in-phase bass should sound clearly fuller and more centered. If the out-of-phase tone instead sounds louder or more solid, one speaker is wired with reversed polarity. Swap the + and − wires on that speaker. This mostly matters for passive stereo speakers; it has little audible effect on headphones.