Move a song in a circle around the listener’s head. On headphones the voice passes from the front, to the right ear, behind, to the left ear, and back to the front, once per orbit.
Three cues the ear uses
Your brain places a sound from differences between the two ears. The converter recreates three of them for a source moving around a circle.
Arrival time. Sound reaches the near ear first. With the source fully to one side the gap is about 0.66 ms, the figure Woodworth’s spherical head model gives for an average head. The far ear’s signal runs through a fractional delay line, so the gap slides smoothly as the source moves rather than stepping one sample at a time.
Head shadow. The head blocks high frequencies on the far side long before it blocks the low end. A low-pass filter at about 1.5 kHz is mixed into the far ear by how far round the source is, and the far ear also drops up to 6 dB in level.
Front and back. Delay and level are identical for a source at 45 degrees in front and 45 degrees behind. Behind the listener the converter takes some of the top octave out of both ears, which is the change the outer ear makes and the one that breaks the tie.
Orbit time and direction
Orbit time is how long one full circle takes, from 1 to 60 seconds. Ten seconds is the familiar slow rotation of most 8D uploads. Under three seconds the motion stops reading as a circle and starts to feel like a fast side-to-side wobble.
Clockwise, seen from above, goes front, right, back, left. Counterclockwise goes front, left, back, right.
Width, head shadow, and mix
Width scales how far to each side the source travels. At 100% it reaches the ears; at 50% it swings through a narrower arc in front and behind; at 0% it sits in the middle as a plain mono sum.
Head shadow sets the strength of the tone cues: the far-ear filter and the dulling behind. At 0% only arrival time and level move, which sounds wider but less like a real room.
Mix blends the original file back in. At 0% the export is the source, unchanged.
Keeping the result loud enough
When the source is at one side, the far ear loses up to 6 dB. Left alone, the overall level would dip each time the source passes an ear. Both ears are raised together to hold the combined power steady around the whole circle, so the track does not pump at the orbit rate.
Summing a wide stereo mix to mono can lower its level, and parts that were out of phase between the channels can cancel. If the result sounds thin, check the mono sum first with the Audio Channel Tool.
Example: a slow vocal orbit
Orbit time 12 s, clockwise, width 100%, head shadow 70%, mix 100%, then the Reverb step at 30% mix.
The voice takes three seconds to reach the right ear, three more to pass behind, and returns to the front at the 12 second mark. Shorten the orbit to 6 s and raise reverb to 40% for the busier rotation common on 8D remixes.