What 8D audio is
"8D audio" is a popular name for music that seems to move around the listener's head. There are no real eight dimensions; the name only describes the effect. It is made with a technique from 3D audio called binaural processing. Our brain locates a sound by tiny differences between the two ears: which ear hears it first, which hears it louder, and how the shape of the head and ears changes the tone. A model of these differences, called an HRTF (head-related transfer function), lets software place a sound in any direction around you using just two headphone channels.
This tool places the song in a virtual space and rotates it in a slow circle around your head using an HRTF. The processing is done in your browser; the song is not uploaded.
Choosing the speed
The most important setting is the rotation speed: how long one full circle takes. 8–15 seconds per circle is the typical relaxed 8D feel. Faster rotation is more dramatic but can feel restless over a whole song, and very slow rotation can be hard to notice. A little room sound or reverb helps the brain place the music outside the head; too much makes it blurry.
Tips for the best effect
- Always use headphones. On speakers, the sound of both channels reaches both ears, and the 3D effect disappears.
- Choose suitable music. Calm songs with a clear vocal, ambient music, lo-fi and acoustic tracks work best. Very dense, loud music loses some punch when it moves away from the centre.
- Close your eyes. It sounds strange, but the effect is stronger when you are not looking at a screen.
- Keep the volume moderate. When the sound passes one ear it gets louder in that ear.
Why it feels so real
Simple left-right panning only changes the volume between the ears, so the sound seems to move along a line inside your head. An HRTF also adds the tiny time difference between the ears, less than a millisecond, and the change in tone caused by your head and outer ear. A sound behind you is slightly darker than one in front, and a sound from the side reaches the far ear later. The brain uses exactly these clues in real life, which is why binaural audio can make music feel like it is outside your head. Everyone's ears are a little different, so the effect is stronger for some listeners than for others.
8D and slowed versions
Many popular 8D videos also slow the song and add reverb. You can do the same: first lower the tempo with Change Speed (about 0.85x with pitch following), then make the 8D version here. To add more depth, the bass booster works well before the rotation. For simple left-right movement without the head model, use the stereo panner with auto-pan.