This is veteran actor Jeff Steitzer. He's done Broadway. Law & Order. Oh, and if you've ever played Halo, chances are you've heard his voice more than Master Chief's, Sgt. Johnson's and Cortana's combined.
Why? Because he's the voice of the game's multiplayer announcer, meaning any time you've heard a gravelly, distant voice grunt "DOUBLE KILL', or "SLAYER", Steitzer is the man behind it. Stay tuned until the end for an awesome Dick Cheney gag.
Like all good voice actors, he looks nothing like you expect, does he?