[Tainojim]

That setup is know as noise canceling.

Also there is another design with a resonator on the rear of a closed system.

Another one called bass port where depending on the acoustics of the room, you can adjust the port to equalize the resonance to the acoustics.

A bass drum can use this very same method through the port hole.

I've seen Yamaha bass drums with two ports but Ive never looked inside of one.