an A4 musical note is 440hz in standard tuning. A soundwave of 440hz in air has a wavelength of over 80 centimeters, so how can a speaker cone that moves less than a centimeter back and forth produce that wave? What am I missing about wavelengths of sound?
user
This is because of how sound waves travel through the air. The moving speaker cone doesn't create the whole wave. Instead, it creates changes in air pressure and forces the air molecules nearby to vibrate, or move back and forth, at the same frequency of it. The vibrating molecules then also create their own changes in pressure, forcing the other molecules in front of them to vibrate together, but with a little delay. As this goes forward, the delay also accumulates, until at a point the total delay is the same as the period of the molecules' vibration. This is where the state of the vibration is the same as the beginning, and we call the distance to accumulate this much delay a wavelength. 
To sum up, the wavelength of the sound wave created by the speaker cone is determined by its vibration frequency. The distance the cone itself travels determines the vibration amplitude of the air molecules, or how loud the sound is.
assistant
That was very interesting. Thank you very much.
user
You're welcome! I'm glad you found it interesting. If you have any other questions or concerns, feel free to ask!
assistant