Think these questions over tonight. Be prepared to answer them, and to test your answers, in class on Wednesday.

Suppose we begin with one generator, hooked up to two speakers about eight feet apart, and generating a sine wave of frequency 300 Hz. People in some locations will hear a loud tone and people in other locations will hear hardly anything. As we try the following things, let us suppose these people do not move.

Suppose we swap the leads on one of the speakers (connect the red wire where the black one was and vice versa). What (if anything) changes? Suppose we swap the leads on the other speaker, while returning the first speaker to its original connections. What (if anything) changes? What if the leads on both speakers are switched from their original connections?

Let's change the generator frequency from 300 Hz to 600 Hz. What (if anything) changes?

Let's change the generator frequency from 600 Hz to 150 Hz. What (if anything) changes?

Why is it that we don't generally hear these strong fluctuations in sound level as we move around the room while listening to a stereo? Is it possible that we ever would?