Hi Dragos, For lecture halls/auditoriums we go with R710s. For a similar size auditorium, we would use from 3 to 5 APs (we might disablesome of 2.4GHz radios).You should also consider the type of applications/ traffic that the clientswill use: web browsing/ e-mail or also video etc..I wouldn't worry about the coverage, but more about the capacity.