Interference with Resonance Boxes
![2 resonant boxes with different tuning forks on top](/media/libraries/college-of-science-and-engineering/physics/images/demo-images/RESBOX1A.jpg)
PIRA 3B50.60
The depth of the cavity in the resonance box shown at right is equal to one-quarter of the wavelength of the sound produced by the tuning fork. After striking the tuning fork with a rubber or padded mallet, walk towards and away from a good reflective surface for sound, like a blackboard. Constructive and destructive interference between the sound produced by the fork and the reflected sound can be easily heard.