from the point of view of a "typical" tv network, what is 4-channel audio? is it two stereo mixes; one with voice, and the other with music & effects? will they accept four seperate mono tracks as an alternative, if correspondingly named? is there a difference btwn 4-ch audio and 4 mono tracks? i'm hoping that the moment i understand the purpose of 4-ch audio, that i will then understand why vegas keeps rendering a 4-channel audio mix that doesn't make sense to me.