X-Fi 3D headphone function - WOW!

[Participant]

Hi all. I've just tried for the first time my Sennheiser ear buds with the 3D headphone function, and although I didn't believe it, it can actually make the sound appear to come from either in front of you or behind. Amazing! How on earth does this work with only 2 channels??

Has anyone else tried this function and what do you think?

 

[Alexrose1uk]

Its very clever, but can be a bit ropey. Basically it works by altering pitch and volume of sounds (as well as left/right), to simulate the effects the human ear has on noise coming from behind.

Basically it tries to 'bend' the sound to the way it thinks we should hear if it was behind us.

 

[smsmasters]

It basically modifies the sine, cosine transforms, reverb etc of the sound wave to simulate "ambience" and positional sound.

If you are any good at physics you would understand this.