3C40.15 - Acoustic Telescope Emitter
To demonstrate how you can place a sound emitter at the focal point of a dish and use it to collimate the beam of sound out into the audience.
Open the storage case and flip up the dish inside. Mount the assembly to the large Samson tripod. The sound emitter plugs into the back of the dish and a white sound reflector fits on the front of the dish located at the focal point. Connect the sound emitter to the amplifier with banana cables. Connect the sound source (iPod) to the amplifier and turn it on.
Turn on the amplifier and the sound source. Point the dish to one side of the classroom. Tell the students to pay attention as you sweep the dish across the classroom. Then tell the students to raise their hand when they think the sound is the largest as you sweep the dish across the classroom a second time. It should be observed that the loudest sound is concentrated directly in front of the dish.