I have always thought that trying to keep one area designated as loud and another as quiet is impractical, especially at a large event when everyone ends up "peg to peg". I think that designating an area as loud can encourage some to be as loud as they can, or that anything goes.
My home club, the Yankee Beemers, have a reputation for being a bit rambunctious. Not puke behind the tent kind but stay up late jawing and drinking beer. We used to rope off "our" area but this gets obnoxious. The spirit behind the MOA rally is supposed to be one of camaraderie. What we do now is find a spot near shade, set up our club gear and have at it. We don't tell anyone where they can or can not camp (been there done that, it's lame) but when we see someone new setting up nearby we do introduce ourselves and welcome them to the neighborhood. We tell them that we can be loud late and we hope to avoid problems before they become problems. We also invite them to be loud with us. If they have children with them we strongly suggest that this is not a kid friendly environment. This year everyone we approached said that is what ear plugs are for and we had no problems. It has been a long time since anyone nearby complained, perhaps we are getting soft.
What I think is a better solution is to have an area designated as family camping. This would accomplish a few goals.
First, it would identify an area where families could camp with other families. This would be great for the kids as they might enjoy the rally more if they were camping with other kids.
Second, it would identify an area where folks would be expected to behave with some decorum. Kids go to bed early so it should be quiet. Ideally this area would be large enough so anyone who wanted quiet without children could find a spot.