Understanding Audio

Under 3D audio, I am trying to understand what Pan Level and Spread is for?

Doing some tests but can’t figure it out.

Check out the tutorial on Unity website:

http://unity3d.com/support/documentation/Manual/Sound.html

“Pan 2D Sets how much the engine has an effect on the audio source.”
pretty sure that means you can move the sound to be heard more from either left or right speaker

“Pan Level Sets how much the 3d engine has an effect on the audio source.
Spread Sets the spread angle to 3d stereo or multichannel sound in speaker space.”