A special compression driver speaker is mounted to the left of the glass. When the speaker is set to the resonance of the glass, vibrations will constructively interfere with each other until the glass breaks. This demonstration takes a special speaker, a frequency generator, and an amplifier that can drive the speaker at 120 watts. The action is captured with a high speed flash operating at 1/1,000,000th of a second. This image is one out of a set of two showing the glass before and after it shatters.