Do you need crossfeed for headphones?

The problem

With loudspeakers, both ears receive sound from both speakers, modified by the room and head. Headphones provide much greater channel separation. On some hard-panned recordings, listeners prefer a little mixing between channels; others prefer the original separation. Crossfeed is an optional listening choice, not a treatment or a universal correction.

What crossfeed does

Crossfeed sends a filtered, slightly delayed copy of each channel to the other ear: low frequencies mostly, because the head shadows the highs. It is a small effect by design. It does not create a room, it restores one of the cues a room would give.

bs2b and the presets

Boris Mikhaylov’s bs2b is the best-known open implementation, used by foobar2000 components, many media players and MP95. It has three classic presets:

These are filter parameters, not a frequency-independent measurement of the level at each ear. In these presets, the larger feed-level value corresponds to a gentler effect; compare the actual result rather than interpreting the number as a universal room simulation.

How to decide

1. Pick a record with hard panning: early Beatles, sixties jazz, Hendrix.
2. Switch crossfeed on at Chu Moy. The instruments should move towards the centre and slightly forward, not collapse into mono.
3. Switch it off. If the difference feels like relief when it is on, keep it. If you miss the width, try Jan Meier, or leave it off for modern mixes.

What it is not

Crossfeed is not head-tracked spatial audio or a surround decoder. Its filtering and channel mixing can change stereo width and frequency response. Compare it at a comfortable level and keep it off if you prefer the original presentation. A subjective preference is not evidence that another player is inaccurate.