This master Halo 2 tip may seem a bit expensive, but if you truly want to become someone to fear on Xbox Live...

Footsteps from Behind

Surround sound speakers are a noteable advantage when playing Halo 2. You will actually hear explosions, gunfire and even footsteps from the direction that they are taking place. Imagine the advantage of suddenly being shot and hearing the direction the shot came from. Imagine hearing the boom of a sniper rifle and knowing the general direction from which the shot was fired. Imagine your fear as you hear the sudden twang of a energy sword unsheathed directly behind you...

Bonus Tip!

A surround sound speaker system will also enable you to hear the location of a flying Banshee or the direction of an oncoming Warthog or Ghost.