Thanks so much for the reply sterretje. I see what you mean about it just staying in S_seriesAOn when the condition is met. Glad you pointed that out.
So, I set it to read the sensor outside the switch/case, put the conditional in the switch/case, and added S_stopped as the initial state.
It works, but the sensor is running the whole time. Is there a way to stop the sensor read when the switch/case is running? I'd like to have it complete all the cases each time something is in range of the sensor.
Still looking into the sound issue...