19. a pair of in-phase stereo speakers are placed next to each other, 0.600 m apart. you stand directly in front of one of the speakers, 1.000 m from the speaker. what is the lowest frequency that will produce constructive interference at your location? the air temperature is 15.0 degrees celsius.19. a pair of in-phase stereo speakers are placed next to each other, 0.600 m apart. you stand directly in front of one of the speakers, 1.000 m from the speaker. what is the lowest frequency that will produce constructive interference at your location? the air temperature is 15.0 degrees celsius.19. a pair of in-phase stereo speakers are placed next to each other, 0.600 m apart. you stand directly in front of one of the speakers, 1.000 m from the speaker. what is the lowest frequency that will produce constructive interference at your location? the air temperature is 15.0 degrees celsius.