If two speakers are generating a frequency of 280Hz, the smallest separation distance between the speakers that will produce destructive interference at a listener standing in front of them is also known as the wavelength of the sound wave generated.
Using the expression;
Velocity v = frequency f × wavelength ¶
Given frequency = 280Hz, speed of sound v = 338m/s
Substituting this data's in the expression given to get the wavelength will give;
¶ = v/f
¶ = 338/280
¶ = 1.21m
The smallest separation between the speakers that will produce the interference is 1.21m
