Do you need crossfeed for headphones?

The problem

Stereo was mixed for two speakers in a room. Each ear hears both speakers, the far one slightly later and duller because your head is in the way. The brain uses those cues to place sounds in front of you. Headphones feed each ear only its own channel. A sound panned hard left exists only in your left ear, which never happens in nature. With early stereo, where the drums are on one side and the vocal on the other, that is tiring. With modern mixes, it makes the sound sit inside your head rather than in front of it.

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:

The dB figure is how much quieter the far ear is than the near one, so the larger number is the weaker effect.

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 spatial audio, 8D or a surround virtualiser. It adds no reverb and no head tracking. Done properly, the centre of the mix stays where it was; designs that stack an extra delay on top of the filter can hollow out the midrange around 1 kHz, which bs2b avoids.