Ensures the "Rear Left" sound actually comes from the speaker behind your left shoulder. Phase Alignment:

| Channel | Audio Cue (Typical) | What to Check | | :--- | :--- | :--- | | | Pink noise or a woman saying "Left" | Sound comes only from the left tower/satellite. | | Front Center | Voice saying "Center" or a door knock | Clear dialog from the center speaker (crucial for movies). | | Front Right | Pink noise or "Right" | Symmetrical volume compared to Front Left. | | Surround Right | Static hiss or "Right Surround" | Sound comes from behind/ beside your right ear. | | Surround Left | Static hiss or "Left Surround" | Sound comes from behind/ beside your left ear. | | Subwoofer (LFE) | A deep rumble or a man saying "Subwoofer" | You should feel vibration, not necessarily "hear" a tone. |

You’ve just unboxed a new home theater system. You have five speakers, one subwoofer, and a receiver flashing “Dolby Digital.” But how do you know it’s working correctly?