Two loudspeakers, A and B (Fig. 16.40), are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. Consider point Q along the extension of the line connecting the speakers, 1.00 m to the right of speaker B. Both speakers emit sound waves that travel directly from he speaker to point Q.
(a) What is the lowest frequency for which constructive interference occurs at point Q?
(b) What is the lowest frequency for which destructive interference occurs at point Q?