AKG C 400 BL User Instructions page 18

Fig. 3
18
2.1. Placement
2.1.1. General Recording/Sound Reinforcement Use
Place the microphone on the floor about 7 to 16 feet
(2 to 5 m) in front of the talkers.
Choose the actual woking distance such that all sound
sources will be within the microphone's pickup angle
(50° above the floor).
Make sure to point the microphone away from the
sound system loudspeakers. (Refer to fig. 3.)
Listen to the microphone at several different locations
and install the microphone where it sounds best.