Subwoofer crossover

A subwoofer crossover is the setting, either on the subwoofer itself or in a receiver's speaker configuration menu, that decides the frequency point where deep bass hands off from the main speakers to the subwoofer. Frequencies below the crossover point go to the sub, while everything above it stays with the front, center and surround speakers, which are usually not built to handle very low bass cleanly.

80 Hz is the most common starting point and matches the default used in most receiver setup wizards and calibration routines, based on the assumption that smaller bookshelf or in-wall speakers cannot reproduce much below that. Larger tower speakers with their own substantial bass drivers can sometimes use a lower crossover point, letting them share more of the bass load with the subwoofer.

A common mistake is leaving every speaker set to full range alongside an active subwoofer, which causes bass to overlap and sound boomy or muddy at certain frequencies. Another is setting the crossover too low for small speakers, which forces them to strain on bass they were not designed to reproduce and can lead to distortion or even damage over time.