1. The problem statement, all variables and given/known data Speakers L_1 and L_2 are placed at a 2 m distance from each other. The speakers send out soundwaves that are in the same phase and the loudness (?) is examined in the point P (see figure). The velocity of the sound is 343 m/s and the distance L_2P is 6 m. L_1 L_2 P (right triangle) a)Which is the lowest frequency that causes a maximum in P? b)Which is the highest frequency that causes a minimum in the point P? Answer is 1060 and 528 Hz. 2. Relevant equations v=fλ 3. The attempt at a solution With maximum, do they mean that both the sound waves should have antinodes at the same time in P? I've been trying different ways but I'm not getting it.