how far off the wall

I undesrstand that a speaker should be given some room to breath, that is to pull it a couple of feet of the wall. With my kef reference fours I found this to be simple. The speakers are enclosed and so i measured the disstance from the back of the speaker to the wall behind it, and advanced it the need distance. With the Martin logan vantage should i measure from the woffer enclouser or from the electrostatic surface. thanks,cj