I'm new here, and perhaps my question is really simple. I have an overdub project with one instrument (a trombone) and four microphones. Four melodic parts have been recorded into DP, so with four mics recording each part, that makes a total of 16 tracks. The tracks are grouped by part, so that I can move one fader in a group and my nice balance of levels on the four mics goes up and down together for the corresponding voice. Simple, right?
Ok, now I want to graphically automate the volume on a part-by-part basis. But but but... if I apply automation to the entire group (e.g., the four tracks that make up "part 1"), the balance between the four mics is lost. All mics go to that one level specified by the automation insert in one of the tracks. Now I sound like a buffalo in heat!
Somebody help me out here.
How do I keep my definition mic (front and center) constantly at the highest level of the group, while automating volume for the group of four mics together? I suppose it would be easy to bounce the tracks down to a stereo track and automate that -- but I would like to be able to adjust the balance between the mics specially in certain parts of the tune. That is to say, sometimes I just want the room mic by itself, while other times I might want only the definition mic. 
It would be way cool if I could draw one automation line for the volume of the top track in a group of four, and have the others follow relative to the top track. For example, if track 1 goes from -6dB to -3dB, then track 2 goes from its starting place at -10dB to -7dB. Then I can suspend the group to automate and adjustment of the balance between the mics. Isn't this a simple thing to do? Many thanks for your help if you can tell me the magic for this.
B