Audio Channel L/R Speaker & Phase Tester

When two speakers or headphone drivers are wired out of phase, one driver pushes forward while the other pulls backward. When listening to in-phase sound, the audio feels solid and centered in your forehead. When out of phase, bass cancels out completely and sound seems hollow and coming from behind your ears.

Wearing headphones backwards, reversing RCA or banana plug speaker cables, or incorrect stereo wiring in cars are common causes of reversed channels.

The phantom center is the acoustic illusion that sound is originating from directly between two stereo speakers when identical in-phase signals are played in both channels.