system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does a dynamic driver produce bass and treble frequencies at the same time?
gpt
Say you're on a river ferry, and that ferry is constantly moving back and forth between the two banks of the river at 2 mph. We'll assume it takes 200 seconds for a round-trip.

Let's also say that while the ferry is in motion, you constantly run from the front of the ferry to the back at 10 mph, and we'll say you need 20 seconds for a round-trip.

You're going back and forth at 1/20 Hz on top of the ferry and the ferry itself is going back and forth at 1/200 Hz. So you're 'oscillating' at two different frequencies at the same time.

The membrane of a speaker can do the same thing. You can have a slow oscillation while playing a bass note and at the same time it can play a high note by adding a fast oscillation on top of that.