andychamp has the idea - WALK AROUND the room listening for the sweet spot - this is where your room mic goes. it's not rocket science. flip the phase switch in & out - you shouldn't have terrible dramas if you allow a bit of distance. JUST LISTEN to what the track needs....maybe it just needs that bit more air in behind the OHs.....maybe it needs a huge crushed hall-mic sound (in which case stick the mic out in the hall and nuke it!).....maybe it needs a tight dry drum sound.........at the end of the day you gotta be guided by the song - not the drummer!!!......there are no rules - but there is shite!