I would agree with @NolanHerring It should not matter where you connect the cable as long as you are connecting them to the right radio i.e, you should be connecting both the cables to either 2.4Ghz radio or to the 5 Ghz radio. You should be fine as long as you follow that.
Ok cool, thanks. I was kind of thinking that since on the MR84 the ant ports were dual band that it didn't really matter. I just couldn't find any documentation to verify.
I ran into the same issue concerning documentation. The distance between the antenna’s should be at least one wave length. Have no idea what the maximum distance is but keep in mind to far apart will increase the coverage angle and that might affect your intended coverage.
a few weeks ago I opened a thread about the MR84 and how to use the antennas
Take a look maybe the discussion has some useful information for you.
There are two 4-lead antennas for the MR42E/53E and for the MR84 you can use the Stadium antenna or a third party antenna. The 2 antenna setup is a bit odd and I wonder why they designed them the way they did (considering the fact that Cisco Enterprise has enough templates for antennas to use).
Both antenna had a large overlapping area, so they don't point to the same direction. It's about 25° difference.
Is someone here who is using the stadium antenna? It's huge and expensive!
I've considered the MR84 with a stadium antenna for a wharehouse because this antenna has a narrow beam ideal for getting the signal between the racks but we went for the MR42E with the narrow patch antenna fot the initial design. Things might change, have to get feedback about what the enviroment will be in the wharehouse.
Acceltext has a great range of products. The AP mount looks great.