Two in-phase loudspeakers are positioned all along a wall and are separated through a distance of 4.00 m. They emit sound having a frequency of 514 Hz. A person is standing away from the wall, in front of one of the loudspeakers. Determine the closest distance from the wall the person can stand and hear constructive interference? The speed of sound in air is around 343 m/s.
i) 1.64 m
ii) 1.15 m
iii) 0.344 m
iv) 0.729 m