Room correction

Room correction is a calibration feature built into most modern AV receivers, using an included microphone placed at the main seating position. The receiver plays test tones through each speaker, measures how the room's walls, furniture and layout affect that sound, and then automatically adjusts each speaker's volume level, distance-based timing delay, and sometimes frequency response to compensate for the room's quirks.

This matters because no two rooms sound the same, even with identical speakers, due to differences in wall material, furniture, ceiling height and speaker placement. Without correction, one speaker might arrive at the listener's ears slightly later than another, or a corner-placed subwoofer might sound boomier than intended, both of which room correction can measurably improve with a few minutes of setup.

A common mistake is running the calibration microphone from an unusual height or angle instead of at actual ear level in the primary seat, which skews the measurement. Another is treating room correction as a total fix for bad speaker placement or an untreated room, when it works best as a fine-tuning step layered on top of reasonably good physical setup, not a replacement for it.